WSR 19-16-156

PROPOSED RULES

BUILDING CODE COUNCIL

[Filed August 7, 2019, 11:06 a.m.]

Original Notice.

Preproposal statement of inquiry was filed as WSR 19-06-073.

Title of Rule and Other Identifying Information: Chapter 51-50 [51-51] WAC, Adoption and amendment of the 2018 International Residential Code.

Hearing Location(s): On September 13, 2019, at 10:00 a.m., at the CenterPlace Regional Event Center, 2426 North Discovery Place, Spokane Valley, WA 99216; and on September 27, 2019, at 10:00 a.m., at the Department of Enterprise Services, Presentation Room (1213), 1500 Jefferson Street, Olympia, WA 98504.

Date of Intended Adoption: November 8, 2019.

Submit Written Comments to: Doug Orth, 1500 Jefferson Street S.E., Olympia, WA 98504, email SBCC@des.wa.gov, by September 27, 2019.

Assistance for Persons with Disabilities: Contact Carrie Toebbe, phone 360-407-9255, email carrie.toebbe@des.wa.gov, by September 4, 2019.

Purpose of the Proposal and Its Anticipated Effects, Including Any Changes in Existing Rules: The proposed rules adopt the 2018 edition of the International Residential Code (IRC), published by the International Code Council (ICC), with state amendments to incorporate proposed changes as adopted by the Washington state building code council (SBCC). The rules will provide increased clarity and life safety measures for building construction in Washington state.

SUMMARY OF PROPOSED CHANGES

2018 IRC

Amendments to Chapter 51-51 WAC*

	WAC	Section	Changes in 2018	Discussion
1	51-51-000		Chapter title	Updated to address the 2018 IRC.
2	51-51-003		Adopts by reference the IRC	Updated to address the 2018 IRC.
3	51-51-008		Establishes the effective date	Updated from July 1, 2015, to July 1, 2020.
4	51-51-01010		Addresses appendix renumbering	Response to appended renumbering in the 2018 code.
5	51-51-0106	R106.1	Submittal documents	Allows digital format permit submission.
6	51-51-0202	R202	Definitions	Deletes the amendment definition of Air impermeable insulation that is now defined in the 2018 code.
7				Added definition for Balanced Whole House Ventilation.
8				Modifies the definition of Building.
9				Modifies Existing Building definition.
10				Added definition for Distributed Whole House Ventilation.
11				Modifies Dwelling Unit definition.
12				Deletes Battery System, Stationary Storage definition. Adds Energy Storage Systems (ESS) definition.
13				Defines Floor Area.
14				Modifies the definition of Lot and Lot Line.
15				Modifies definition of Landing Platform.
16				Modified definition of Local Exhaust.
17				Modifies definition of Loft.
18				Deleted definition for Mixed Ventilation Zone.
19				Modified the definition of Townhouse and adds a definition for Townhouse Unit. Defines minimum length to be considered appropriate width to a yard or public way.
20				Modified definition of Whole House Ventilation System.
21	51-51-0301	R301.2.2.3.1	Design criteria	Amendment deleted because it is now addressed in the 2018 code.
22		Table R301.5	Minimum uniformly distributed live loads	Changes the live load from forty to sixty for exterior balconies and decks.
23	51-51-0302	R302.1	Exterior walls	Amendments deleted because they are now addressed in the 2018 code.
24		R302.2.1 R302.2.2 R302.2.3 R302.2.4 R310.1	Double walls Common walls Continuity Parapets for townhouses Emergency escape and rescue opening required	Addresses the new definition of Townhouse Unit as it applies to the separation of Townhouse Units and emergency escape.
25		Table R302.1(1) Table R302.1(2)	Exterior walls, footnote b Dwellings with fire sprinklers, footnote c	Addresses the situation where there are no vents at the underside of the rake overhang, or in any walls underneath the rake overhang. This section has been modified to be more generic so that the concept can be applied at gable, hip and any other roof style with overhangs.
26		R302.2	Townhouses	Clarifies that the townhouse common wall be "tight against" two locations, the inside face of the exterior wall and the underside of the roof sheathing. Requires common walls to continue to the exterior sheathing of the exterior wall. A new exception allows (2) 2x wood studs to be used to extend the common wall through the exterior wall stud cavity.
27		Figure R302.2(2)	Townhouse separation overhang protection	Aligns values in Figure R302.2(2) with the value given for protecting projections in Table R302.1(2).
28		R302.2.6	Structural independence	Option One: Addresses the new definition of Townhouse Unit as it applies to the separation of Townhouse Units and emergency escape. Option Two: Deletes amendment.
29		R302.3 R302.3.1 R302.3.2 R302.3.3	Two family dwellings	Addresses unit separation requirements and supporting construction requirements.
30		R302.4.1	Through penetrations	Includes fire sprinkler piping in the exception.
31	51-51-0303	R303.9	Required glazed openings	Addresses the length of the clear vertical space.
32	51-51-0308	R308.4.4 R308.4.4.1	Glazing in guards and railings Structural glass baluster panels	Amendments deleted because they are now addressed in the 2018 code.
33	51-51-0310	R310.1	Emergency escape and rescue opening required	Addresses minimum width.
34		R310.1.1	Operational constraints and opening control devices	Addresses the location of the window control device.
35		R310.2.4	Emergency escape and rescue openings under decks and porches	Addresses the length of the clear vertical space.
36	51-51-0311	R311.7.3	Vertical rise	Converts an inch dimension to feet and inches.
37	51-51-0313	R313	Automatic fire sprinkler system	Addresses fire sprinkler systems for townhouses.
38	51-51-0314	R314	Smoke alarms and heat detection	Modifies section to address heat detection in residential garages.
39		R314.2.2 R314.4	Alterations, repairs and additions Interconnection	Addresses the required location of smoke alarms in accessory dwelling units and how they should be interconnected.
40	51-51-0315	R315.3	Location	Addresses an error made when submitting the WAC language for the 2015 code.
41	51-51-03240	R324.1 R324.2 R324.3.1 R324.4.1 R.24.4.2 [R324.4.2] R324.5 R324.6	General Solar thermal systems Equipment listing Roof load Wind resistance Building-integrated photovoltaic systems Ground-mounted photovoltaic systems	Amendments deleted because they are now addressed in the 2018 code.
42	51-51-0325	R325.6	Habitable attic	Habitable attics are considered a story unless the structure is fully sprinklered.
43	51-51-0326	R326.1	General	Adds requirements for sleeping lofts.
44		R326.2 R326.2.2 R326.3 R326.3.1.1 R326.3.1.2 R326.3.1.3 R326.3.1.4 R326.3.1.5 R326.3.1.6 R326.3.1.7 R326.3.2 R326.3.2.1 R326.3.2.2 R326.3.3 R326.3.4 R326.4 R326.5	Sleeping loft area and dimensions Minimum horizontal dimensions Sleeping loft access and egress Headroom Width Treads and risers Landings Landing platforms Handrails Stairway guards Ladders Size and capacity Incline Alternating tread devices Ships ladders Sleeping loft guards Emergency escape and rescue openings	Moves and modifies language from the Tiny Home appendix and places it here.
45	51-51-0327	R327.1 R327.2 R327.3 R327.4 R327.5 R327.6 R327.6.1 R327.7	General Equipment listing Installation Electrical installation Ventilation Commissioning Installation prior to closing Protection from impact	Replaces the term Stationary Battery Storage System with ESS. It also includes new requirements for commissioning an ESS and provides for a handoff of the commissioning paperwork to the owner for new construction.
46	51-51-0325 now 51-51-0328	R328	Adult family homes	Number adjustment to accommodate renumbering in the model code.
47	51-51-0326 now 51-51-0329	R329	Family home child care	Number adjustment to accommodate renumbering in the model code.
48	51-51-0327 now 51-51-0330	R330	Protection against radon	Number adjustment to accommodate renumbering in the model code.
49	51-51-0328	R328	Mezzanines now reserved	Amendments deleted because they are now addressed in the 2018 code.
50	51-51-0329 now 51-51-0326	R326	Swimming pools, spas, and hot tubs	Number adjustment to accommodate renumbering in the model code. Updated to address the 2018 code.
51	51-51-0403	R403.1.6	Foundation anchorage	Allows wet setting anchor bolts for attaching wood sills to foundations.
52	51-51-0404	R404.1.3.3.6	Form materials and form ties	Allows wet setting anchor bolts for attaching wood sills to foundations.
53	51-51-0507	R507.1	Decks	Reminds designers that they must consider live load and ground snow load.
54		Table R507.3.1	Minimum footing size for decks	Modifies dimensions for some footings. Modifies footnote addressing bearing.
55		R507.4	Deck posts	Addresses deck posts.
56		Table R507.4	Deck Post Height	Modifies table.
57		R507.5	Deck beams	Addresses new table numbering.
58		Table R507.5(1)	Maximum deck beam span - 40 psf live load	Modifies table and footnotes.
59		Table R507.5(2)	Maximum deck beam span - 50 psf live load	New table and footnotes.
60		Table R507.5(3)	Maximum deck beam span - 60 psf live load	New table and footnotes.
61		Table R507.5(3)	Maximum deck beam span - 70 psf live load	New table and footnotes.
62		R507.6	Deck joists	Deletes text addressing cantilevering.
63		Table R507.6	Maximum deck joist spans	Modifies table and footnotes.
64		R507.9.1.2	Band joist details	Requires the band joists used to attach the deck ledger to be in compliance with sawn lumber or the engineered wood rim board.
65		Table R507.9.1.3(1)	Deck ledger connection to band joist	Modifies table and footnotes.
66		R507.9.2	Lateral connection	Amendment updated to synchronize with the revised section numbers and titles in the model code.
67	51-51-0602	R602.1.1.1	Used sawn lumber	Gives structural properties for used lumber.
68		R602.7.5 R602.9 R602.10.10	Supports for headers Cripple walls Cripple wall bracing	Deletes amendment not adopting R602.7.5. Number adjustment to accommodate renumbering in the model code.
69	51-51-0608	R608.1 R608.5.1	General Concrete and materials for concrete	References ACI 332 Residential Code Requirements for Structural Concrete.
70	51-51-0703	R703.2	Water-resistive barrier	Provides a more flexible definition of water-resistive barriers.
71	51-51-1006	R1006.6	Solid fuel burning appliances and fireplace	Number adjustment to accommodate renumbering in the model code.
72	51-51-1504	M1504.3	Exhaust openings	Allows for intake/exhaust combination terminations.
73	51-51-1507	M1507.3.2	Control operation	Addresses labeling.
74		M1507.3.3.1	Testing	Adds testing requirements for whole house mechanical ventilation systems.
75	51-51-4400	Standards	Modified ANCE NMX-J-521/2-40-ANCE-2019/CAN/CSA-22.2 No. 60335-2-40-19/UL 60335-2-40-2019 (if published)	Updates standard.
76			Added ASTM E2556/E2556M-10	Provides a more flexible definition of water-resistive barriers.
77			Added ANSI LC1/CSA 6.26—18	Added standard.
78			Modified CSA CAN/CSA/C22.2 No. 60335-2-40-2019 (if published)	Updates standard.
79			Modified UL/CSA/ANCE 60335-2-40-2019 (if published)	Updates standard.
80	51-51-60103	AF103	Requirements	Adjusts numbering to accommodate renumbering in the model code.
81	51-51-60104	Appendix Q	Tiny houses	Adopts and modifies appendix.
82		AQ101.1	Scope	Adopted.
83		AQ102.1	General	Adopted.
84			Definitions	Adopted and modified Tiny House definition.
85		AQ103	Ceiling height	Adopted and modified.
86		AQ104.1	Testing for tiny houses	New section addressing air leakage.
87		AQ104.1.1	Whole house mechanical ventilation	New section addressing whole house mechanical ventilation.
88		AQ104.1	Tiny house	New section addressing energy usage compliance.
89	51-51-60105	Appendix Q now Appendix U	Dwelling unit fire sprinkler systems	Adjusts numbering to accommodate renumbering in the model code.
90	51-51-60107	Appendix V	Fire sprinklers	Adjusts numbering to accommodate renumbering in the model code.

*Note:

Those not listed on the table above remain as adopted in 2015.

Reasons Supporting Proposal: RCW 19.27.031 and 19.27.074.

Statutory Authority for Adoption: RCW 19.27.031, 19.27.074.

Statute Being Implemented: RCW 19.27.031, 19.27.074.

Rule is not necessitated by federal law, federal or state court decision.

Name of Proponent: SBCC, governmental.

Name of Agency Personnel Responsible for Drafting and Implementation: Richard Brown, 1500 Jefferson Street S.E., Olympia, WA 98504, 360-407-9277; and Enforcement: Local jurisdictions having authority.

A school district fiscal impact statement is not required under RCW 28A.305.135.

A cost-benefit analysis is required under RCW 34.05.328. A preliminary cost-benefit analysis may be obtained by contacting Richard Brown, 1500 Jefferson Street S.E., Olympia, WA 98504, phone 360-407-9277, email Richard.brown@des.wa.gov.

The proposed rule does impose more-than-minor costs on businesses.

There are costs imposed by the proposed rules but the costs do not fall disproportionately on small businesses. These rules will not affect the distribution of impacted work, whether by small businesses or not, doing the work. The rules do not affect employment, reporting or recordkeeping.

Small Business Economic Impact Statement

(RCW 19.85.040)

Description: SBCC is filing a proposed rule to adopt the updated 2018 edition of IRC (chapter 51-51 WAC). Since 1985 SBCC has been responsible to update to new editions of the Building Code per RCW 19.27.074. IRC is updated every three years by ICC. The code development process conducted by the model code organization is open to all interest groups within the design and construction industry and from governmental organizations. See www.iccsafe.org for more information about the model code development process.

The administrative compliance requirements are under the authority of the local government, RCW 19.27.050. Compliance activities including permit issuance, plan review and approval, and inspections, occur at the local level. Requirements for construction document submittal and other reporting requirements are determined by the local jurisdiction and are consistent with previously established policies. The proposed amendments to chapter 51-51 WAC include specific technical requirements for building construction to be consistent with national standards.

Professional Services: Washington has had a statewide Building Code in effect since 1974. The local enforcement authority having jurisdiction administers the codes through the building and/or fire departments. Administrative procedures for state Building Code compliance are established and will not be changed by the adoption of the update to the current building codes. Small businesses will employ the same types of professional services for the design and construction of buildings and systems to comply with the state Building Code.

The proposed rule updates the state Building Code and does not require additional equipment, supplies, labor or other services. Services needed to comply with the Building Code are existing within the construction industry as required by the local authority having jurisdiction.

Costs of Compliance for Businesses: The cost of compliance incurred by Washington businesses includes training and educational materials. IRC 2018 model code costs $99 + tax, shipping and handling. This publication is also available online at http://codes.iccsafe.org/I-Codes.html. ICC chapters offer training for continuing education credits to architects, engineers and building inspectors for $285 (in 2016).

The Building Code technical advisory group (TAG) determined there is a cost for compliance on businesses for the following proposed state amendments.

1. TABLE 301.5, R507.1, TABLE R507.3.1, R507.4, TABLE R507.4, R507.5, TABLE R507.5, TABLE R507.5(2) (new), TABLE R507.5(3) (new), TABLE R507.5(4) (new), R507.6, TABLE R507.6, TABLE R507.9.1.3(1): Clarifies the state's deck live load interpretation and provides a footnote to TABLE 301.5 that allows using Section R507. This proposal also aligns the IRC deck and balcony live load requirements with IBC and ASCE7. This will increase the cost of construction. A full parametric study of every size, shape, and configuration of decks is not practical, as there are too many variables, however, the biggest impacts are to ledger bolt spacing and footing sizes; how much depends on the particulars of the design.

2. Section(s): TABLE R302.1(1) footnote b and TABLE R302.1(2) footnote c Reduction of fire-resistance rating on underside of rake overhang: If there were no vents at the underside of the rake overhang, or in any walls underneath the rake overhang, both of which allow fire to freely move into attic areas, then there should be no requirement to rate the underside of the rake overhang. This section has been modified to be more generic so that the concept can be applied at gable, hip and any other roof style with overhangs. This will decrease the cost of rating the rake overhang in cases where there are no openings into the attic that could cause fire to spread. In this case, it would eliminate the cost of a one hour rating for the underside of the rake.

3. Section R302.2.6 Structural independence: Removes the structural independence section for townhouses in IRC. This will decrease the cost of construction since it is eliminating requirements and makes code compliance easier when designing townhouse projects.

4. Section R302.4.1 Through penetrations: Listed fire sprinkler piping is ignition resistant and will not sustain combustion. Allowing common fire sprinkler piping to protect multiple units in a townhouse can significantly reduce installation costs, and IBC now allows penetration of townhouse separation walls in any townhouse that does not exceed the height and area limits. The code change proposal will decrease the cost of construction. The allowance for sprinkler piping to penetrate townhouse separation walls will reduce the infrastructure required to install a fire sprinkler system in some cases by allowing a shared feed for multiple units.

5. Section R313 Automatic fire sprinkler systems: Requires fire sprinklering for townhouses composed of five or more townhouse units. Installation costs for fire sprinklers in townhouses are offset by cost savings that can be realized in other aspects of construction, including:


•	Reduced fire ratings of townhouse separation walls.
•	Elimination of the requirement to provide a fire-resistant floor-ceiling system between unfinished basements and occupied areas.
•	Reductions in road width, number of required access roads into a community, and elimination of some portions of fire access roads based on permissible increase in maximum distance from an access road to the most remote point of buildings (normally limited to one hundred fifty feet). These allowances will vary based on local jurisdiction fire code access requirements.
•	Reductions in minimum required water supply flow rate, smaller water mains, and possible elimination of some fire hydrants. These allowances will vary based on local jurisdiction fire code water supply requirements.
•	Allowance for a single means of escape window or door for the entire basement, which may eliminate not only additional windows for sleeping rooms, but also the associated window well, escape ladder, fall protection for the window well opening and issues with sealing below-grade wall openings from water infiltration.
•	Increased portion of roof area permitted to have solar panels (R324.6), which increases available solar generating capacity.
•	Permissible area of a mezzanine increases from 1/3 of the floor area of the room with a mezzanine to 1/2 (R325.3). This permits increased design flexibility for a top-story mezzanine versus having a fourth story in a townhouse, which falls out of IRC scope and forces IBC compliance.
•	Permissible enclosure of mezzanines in rooms not exceeding two stories above grade plane versus requiring openness to the room with walls not exceeding 36 inches in height (R325.5).

Many of these cost offsets relate to design options that are difficult to quantify because they relate to specific architectural design features, such as the inclusion of mezzanines, or on local fire code requirements that are unique to specific jurisdictions. However, the cost offsets associated with permissible reductions in townhouse separations and unfinished basement floor-ceiling assemblies can be quantified. Based on the highest-cost system from model runs and parameters described above, the net monthly payment for fire sprinklers is $1.23, or approximately $15/year.

6. Section R314 Smoke alarms and heat detection: Addresses heat detectors in garages. An interconnected heat detector or heat alarm will increase the cost of construction by about $100, which includes installation. If a new garage is attached to an existing dwelling that has only battery powered smoke alarms installed, the heat detector or heat alarm will require the installation of an interconnected alarm or smoke alarm to be installed in the dwelling for the purposes of providing occupant notification. Under this scenario, the total cost will increase to about $200.

7. Section R325.6 Habitable attic: This change will require habitable attics above the third floor to be considered a floor unless the building if [is] fully sprinklered. This will increase the cost of construction where this is applicable by requiring the habitable attic to be built to the same standard as the floors below.

8. Sections R403.1.6 and R404.1.3.3.6 Foundation anchorage and form materials and form ties: This allows wet-setting anchor bolts. This will reduce the labor and time needed in foundation construction.

9. Appendix Q Tiny house: This takes an important part of Appendix Q and incorporates it into the main sections of IRC. It makes those sections available to all dwelling units that are constructed out of IRC. Additionally, this provides modifications to Appendix Q for tiny houses and addresses some energy code standards for these smaller spaces. This proposal may decrease the cost of construction by allowing flexibility in how smaller dwelling unit spaces are designed and constructed.

Loss of Sales or Revenue: The proposed rules make the state code for building construction consistent with national standards. Businesses with new products or updated test or design standards are recognized in the updated Building Code.

The update will result in some cost outlay for some small businesses for specific building projects for a transition period. Other small businesses would see an increase in revenue. The amendments to the building codes affect over twenty-five thousand (in 2012) small businesses in the state, where construction activity occurs. The primary intent of the amendments is to improve the safety features in buildings and provide consistency and fairness across the state, for a predictable business environment. The amendments should result in enhanced safety and value in buildings.

Cost of Compliance for Small Businesses (determine whether the proposed rule will have a disproportionate cost impact on small businesses, compare the cost of compliance for small business[es] with the cost of compliance for the ten percent of businesses that are the largest businesses): The majority of businesses affected by the updates to the building codes are small businesses; over ninety-five percent of those listed in the construction and related industries have under fifty employees. The costs per employee are comparable between the largest businesses and the majority of small businesses. The cost to comply with the updated codes is not a disproportionate impact on small business[es]. Where SBCC found the cost of compliance for small businesses to be disproportionate, the proposed rule mitigates the cost. The proposed rules include a definition of small business and provide exceptions for compliance with the updated rule.

Reducing the Costs of the Rule on Small Businesses: The revision history for the 2018 model code amendments shows several hundred amendments proposed by industry and local governments which add flexibility and clarity to the code and coordinate rules, and represent a savings for small business building owners and operators.

SBCC conducted a detailed review process, including participation at the national code development hearings, to document significant economic impacts of the proposed code amendments.

Small Businesses Involved in the Development of the Rule: For IRC, SBCC conducted ten open public meetings of the Building Code TAG, available via telephone conference bridge and over the internet, and allowed comment on every item on every agenda. For IRC TAG the SBCC appointed six representatives of all segments of the business and construction community to serve on the TAGs.

List of Industries: Below is a list of industries required to comply with the Building Code:

North American Industry Classification System (NAICS) Code	NAICS Code Definition	Number of Establish- ments in Washington State	TOTAL Annual Payroll	TOTAL Annual Revenue	AVG Annual Payroll	AVG Annual Revenue	1% of Avg Annual Payroll	0.3% of Avg Annual Revenue
236115	New single-family housing construction (except for-sale builders)	1261	$186,272,000	---	$147,718	---	$1,477	---
236116	New multifamily housing construction (except for-sale builders)	45	$54,622,000	---	$1,213,822	---	$12,138	---
236118	Residential remodelers	2777	$318,180,000	$1,536,217,000	$114,577	$553,193	$1,146	$1,660
236210	Industrial building construction	53 (s)	$99,790,000	---	---	---	---	---
236220	Commercial and institutional building construction	862	$772,473,000	$6,925,925,000	$896,140	$8,034,716	$8,961	$24,104
238110	Poured concrete foundation and structure contractors	511	$144,643,000	$479,256,000	$283,059	$937,879	$2,831	$2,814
238120	Structural steel and precast concrete contractors	68	$93,454,000	$336,100,000	$1,374,324	$4,942,647	$13,743	$14,828
238130	Framing contractors	417	$79,196,000	$279,226,000	$189,918	$669,607	$1,899	$2,009
238140	Masonry contractors	293	$74,067,000	$215,274,000	$252,788	$734,724	$2,528	$2,204
238150	Glass and glazing contractors	141	$67,626,000	$237,985,000	$479,617	$1,687,837	$4,796	$5,064
238160	Roofing contractors	537	$179,942,000	$660,911,000	$335,088	$1,230,747	$3,351	$3,692
238170	Siding contractors	327	$58,557,000	$286,471,000	$179,073	$876,058	$1,791	$2,628
238190	Other foundation, structure, and building exterior contractors	113	$37,585,000	$123,771,000	$332,611	$1,095,319	$3,326	$3,286
238210	Electrical contractors and other wiring installation contractors	1847	$940,854,000	$3,026,762,000	$509,396	$1,638,745	$5,094	$4,916
238220	Plumbing, heating, and air-conditioning contractors	1664	$959,976,000	$3,169,548,000	$576,909	$1,904,776	$5,769	$5,714
238290	Other building equipment contractors	81	$117,696,000	---	$1,453,037	---	$14,530	---
238310	Drywall and insulation contractors	653	$282,929,000	$723,945,000	$433,276	$1,108,644	$4,333	$3,325
238990	All other specialty trade contractors	547	$182,710,000	$573,308,000	$334,022	$1,048,095	$3,340	$3,144
321213	Engineered wood member (except truss) manufacturing	11	$14,216,000	$79,051,000	$1,292,364	$7,186,455	$12,924	$21,559
321214	Truss manufacturing	22	---	---	---	---	---	---
321219	Reconstituted wood product manufacturing	3	---	---	---	---	---	---
321911	Wood window and door manufacturing	39	$37,814,000	$145,137,000	$969,590	$3,721,462	$9,696	$11,164
321992	Prefabricated wood building manufacturing	18	$6,891,000	---	$382,833	---	$382,833	---
327310	Cement manufacturing	7	---	---	---	---	---	---
327320	Ready-mix concrete manufacturing	93	$74,457,000	---	$800,613	---	$8,006	---
327331	Concrete block and brick manufacturing	18	$11,218,000	---	$623,222	---	$6,232	---
332311	Prefabricated metal building and component manufacturing	9	$3,564,000	---	$396,000	---	$3,960	---
332312	Fabricated structural metal manufacturing	94	$125,755,000	---	$1,337,819	---	$13,378	---
332321	Metal window and door manufacturing	16	$23,776,000	---	$1,486,000	---	$14,860	---
332322	Sheet metal work manufacturing	122	$122,956,000	$573,443,000	$1,007,836	$4,700,352	$10,078	$14,101
335121	Residential electric lighting fixture manufacturing	9	---	---	---	---	---	---
335122	Commercial, industrial, and institutional electric lighting fixture manufacturing	8	$2,625,000	---	$328,125	---	$3,281	---
335129	Other lighting equipment manufacturing	4	---	---	---	---	---	---
423720	Plumbing and heating equipment and supplies (hydronics) merchant wholesalers	168	$82,225,000	$897,748,000	$489,435	$5,343,738	$4,894	$16,031
541310	Architectural services	635	$326,798,000	$921,033,000	$514,643	$1,450,446	$5,146	$4,351
541330	Engineering services	1599	$1,758,825,000	$3,946,553,000	$1,099,953	$2,468,138	$11,000	$7,404
541350	Building inspection services	154	$9,724,000	$28,297,000	$63,143	$183,747	$631	$551
561621	Security systems services (except locksmiths)	109	$86,072,000	$233,388,000	$789,651	$2,141,174	$7,897	$6,424

Note:	Data is blank in some fields to protect data source.
Data Source:	Economic Census of the United States.

Estimate of the Number of Jobs That Will Be Created or Lost: The adoption of the latest code edition is not expected to significantly impact the number of jobs in the construction industry. These rules are likely to be job neutral overall, i.e., they will not result in any job gains or losses. The scheduled effective date of the new edition is July 1, 2020. Building permits issued prior to that date will be vested under the 2015 Building Code. Permits issued for projects under the 2018 code edition will generally start with the 2021 construction season.

A copy of the statement may be obtained by contacting Richard Brown, 1500 Jefferson Street S.E., Olympia, WA 98504, phone 360-407-9277, email Richard.brown@des.wa.gov.

August 5, 2019

Doug Orth

Council Chair

Chapter 51-51 WAC

STATE BUILDING CODE ADOPTION AND AMENDMENT OF THE ((2015))2018 EDITION OF THE INTERNATIONAL RESIDENTIAL CODE

AMENDATORY SECTION(Amending WSR 16-03-025, filed 1/11/16, effective 7/1/16)

WAC 51-51-003International Residential Code.

The ((2015))2018 edition of the International Residential Code as published by the International Code Council is hereby adopted by reference with the following additions, deletions, and exceptions: Provided that chapters 11 and 25 through 43 of this code are not adopted. Energy Code is regulated by chapter 51-11R WAC; Plumbing Code is regulated by chapter 51-56 WAC; Electrical Code is regulated by chapter 296-46B WAC or Electrical Code as adopted by the local jurisdiction. Appendix F, Radon Control Methods, ((and))Appendix Q, Tiny Homes, and Appendix ((Q))U, Dwelling Unit Fire Sprinkler Systems, are included in adoption of the International Residential Code.

AMENDATORY SECTION(Amending WSR 16-03-025, filed 1/11/16, effective 7/1/16)

WAC 51-51-008Implementation.

The International Residential Code adopted by chapter 51-51 WAC shall become effective in all counties and cities of this state on July 1, ((2016))2020.

AMENDATORY SECTION(Amending WSR 16-03-025, filed 1/11/16, effective 7/1/16)

WAC 51-51-01010Scope.

The provisions of the International Residential Code for One- and Two-Family Dwellings shall apply to the construction, alteration, movement, enlargement, replacement, repair, equipment, use and occupancy, location, removal and demolition of detached one- and two-family dwellings, adult family homes, and townhouses not more than three stories above grade plane in height with a separate means of egress and their accessory structures not more than three stories above grade plane in height.

EXCEPTIONS:	1. Live/work units located in townhouses and complying with the requirements of Section 419 of the International Building Code shall be permitted to be constructed in accordance with the International Residential Code for One- and Two-Family Dwellings. Fire suppression required by Section 419.5 of the International Building Code where constructed under the International Residential Code for One- and Two-Family Dwellings shall conform to Appendix ((Q))U.
	2. Owner-occupied lodging houses with one or two guestrooms shall be permitted to be constructed in accordance with the International Residential Code forOne- and Two-Family Dwellings.
	3. Owner-occupied lodging homes with three to five guestrooms shall be permitted to be constructed in accordance with the International Residential Code for One- and Two- Family Dwellings where equipped with a fire sprinkler system in accordance with Appendix ((Q))U.

NEW SECTION

WAC 51-51-0106Section 106—Construction documents.

R106.1 Submittal documents. Submittal documents consisting of construction documents, and other data shall be submitted in two or more sets, or in a digital format where allowed by the building official, with each application for a permit. The construction documents shall be prepared by a registered design professional where required by the statutes of the jurisdiction in which the project is to be constructed. Where special conditions exist, the building official is authorized to require additional construction documents to be prepared by a registered design professional.

EXCEPTION:

The building official is authorized to waive the submission of construction documents and other data not required to be prepared by a registered design professional if it is found that the nature of the work applied for is such that reviewing of construction documents is not necessary to obtain compliance with this code.

AMENDATORY SECTION(Amending WSR 16-03-025, filed 1/11/16, effective 7/1/16)

WAC 51-51-0202Section R202—Definitions.

ADULT FAMILY HOME means a dwelling in which a person or persons provide personal care, special care, room and board to more than one but not more than six adults who are not related by blood or marriage to the person or persons providing the services.

((AIR-IMPERMEABLE INSULATION. An insulation having an air permeance equal to or less than 0.02 L/s-m2 at 75 Pa pressure differential tested in accordance with ASTM E2178 or ASTM E283.))

ATTIC, HABITABLE. A conditioned area complying with all of the following requirements:

1. The occupiable floor area is at least 70 square feet (6.5 m2), in accordance with Section R304.

2. The occupiable floor area has a ceiling height in accordance with Section R305.

3. The occupiable space is entirely enclosed by the roof assembly above, knee walls (if applicable) on the sides, and the floor-ceiling assembly below.

A habitable attic is not considered a story.

BALANCED VENTILATION. This definition is not adopted.

BALANCED WHOLE HOUSE VENTILATION. Balanced whole house ventilation is defined as any combination of concurrently operating residential unit mechanical exhaust and mechanical supply whereby the total mechanical exhaust airflow rate is within 10 percent or 5 cfm, whichever is greater, of the total mechanical supply airflow rate. Intermittent dryer exhaust, intermittent range hood exhaust, and intermittent toilet room exhaust airflow rates above the residential dwelling or sleeping unit minimum ventilation rate are exempt from the balanced airflow calculation.

BATTERY SYSTEM, STATIONARY STORAGE. This definition is not adopted.

BUILDING, EXISTING. A building or structure erected prior to the adoption of this code, or one that has passed a final inspection.

BUILDING. Any one- or two-family dwelling or townhouse, or portion thereof used or intended to be used for human habitation, for living, sleeping, cooking or eating purposes, or any combination thereof, or any accessory structure.

CHILD CARE, FAMILY HOME. A child care facility, licensed by Washington state, located in the dwelling of the person or persons under whose direct care and supervision the child is placed, for the care of twelve or fewer children, including children who reside at the home.

CHILD DAY CARE, shall, for the purposes of these regulations, mean the care of children during any period of a 24 hour day.

CONDITIONED SPACE. An area, room or space that is enclosed within the building thermal envelope and that is directly or indirectly heated or cooled. Spaces are indirectly heated or cooled where they communicate through openings with conditioned spaces, where they are separated from conditioned spaces by uninsulated walls, floors or ceilings, or where they contain uninsulated ducts, piping or other sources of heating or cooling.

DISTRIBUTED VENTILATION SYSTEM. This definition is not adopted.

DISTRIBUTED WHOLE HOUSE VENTILATION. A whole house ventilation system shall be considered distributed when it supplies outdoor air directly (not transfer air) to each dwelling or sleeping unit habitable space (living room, den, office, interior adjoining spaces or bedroom), and exhausts air from all kitchens and bathrooms directly outside.

DWELLING UNIT. A single unit providing complete independent living facilities for one or more persons, including permanent provisions for living, sleeping, eating, cooking and sanitation. Dwelling units may also include the following uses:

1. Adult family homes, foster family care homes and family day care homes licensed by the Washington state department of social and health services.

2. Offices, mercantile, food preparation for off-site consumption, personal care salons or similar uses which are conducted primarily by the occupants of the dwelling unit and are secondary to the use of the unit for dwelling purposes, and which do not exceed 500 square feet (46.4 m2).

((3. One accessory dwelling unit, which need not be considered a separated dwelling unit, provided:

a. The accessory dwelling unit is constructed within an existing dwelling unit.

b. Either the accessory dwelling unit or primary dwelling unit is owner-occupied.

c. All required smoke alarms in the accessory dwelling unit and the primary dwelling unit are interconnected in such a manner that the actuation of one alarm will activate all alarms in both the primary dwelling unit and the accessory dwelling unit.))

ENERGY STORAGE SYSTEMS (ESS). One or more devices, assembled together, capable of storing energy in order to supply electrical energy at a future time.

FIRE SEPARATION DISTANCE. The distance measured from the foundation wall or face of the wall framing, whichever is closer, to one of the following:

1. To the closest interior lot line; or

2. To the centerline of a street, an alley or public way; or

3. To an imaginary line between two buildings on the lot.

The distance shall be measured at a right angle from the wall.

FLOOR AREA. The area within the inside perimeter of exterior walls of the building. The floor area of a building, or portion thereof, not provided with surrounding exterior walls shall be the usable area under the horizontal projection of the roof or floor above.

LOCAL EXHAUST. An exhaust system that uses one or more fans to exhaust air from a specific room or rooms within a residential dwelling or sleeping unit.

LOT. A measured portion or parcel of land considered as a unit having fixed boundaries.

LOT LINE. The line which bounds a plot of ground described as a lot in the title to the property.

MEZZANINE, LOFT. An intermediate level or levels between the floor and ceiling of any story.

MIXED VENTILATION ZONE. This definition is not adopted.

SALT WATER COASTAL AREA. Those areas designated as salt water coastal areas by the local jurisdiction.

SMALL BUSINESS. Any business entity (including a sole proprietorship, corporation, partnership or other legal entity) which is owned and operated independently from all other businesses, which has the purpose of making a profit, and which has fifty or fewer employees.

TOWNHOUSE. A building that contains three or more attached townhouse units.

TOWNHOUSE UNIT. A single-family dwelling unit in a townhouse that extends from foundation to roof and that has a yard or public way on not less than two sides that extends at least 50 percent of the length of each of these two sides.

WHOLE HOUSE VENTILATION SYSTEM. A mechanical ventilation system, including fans, controls, and ducts, which replaces, by direct ((or indirect)) means, air from the habitable rooms with outdoor air.

AMENDATORY SECTION(Amending WSR 16-03-025, filed 1/11/16, effective 7/1/16)

WAC 51-51-0301Design criteria.

R301.2 Climatic and geographic design criteria. Buildings shall be constructed in accordance with the provisions of this code as limited by the provisions of this section. Additional criteria shall be established by the local jurisdiction and set forth in Table R301.2(1). The local jurisdiction shall designate the salt water coastal areas within their jurisdiction.

((R301.2.2.3.1 Height limitations. Wood-framed buildings shall be limited to three stories above grade plane or the limits given in Table R602.10.3(3). Cold-formed, steel-framed buildings shall be limited to less than or equal to three stories above grade plane in accordance with AISI S230. Mezzanines that comply with Section R328 shall not be considered as stories. Structural insulated panel buildings shall be limited to two stories above grade plane.))

R301.5 Live load. The minimum uniformly distributed live load shall be as provided in Table R301.5.

TABLE R301.5

MINIMUM UNIFORMLY DISTRIBUTED LIVE LOADS

(in pounds per square foot)

Use	Live Load
Uninhabitable attics without storageb	10
Uninhabitable attics with limited storageb, g	20
Habitable attics and attics served with fixed stairs	30
Balconies (exterior) and deckse	60i
Fire escapes	40
Guards and handrailsd	200h
Guard in-fill componentsf	50h
Passenger vehicle garagesa	50a
Rooms other than sleeping rooms	40
Sleeping rooms	30
Stairs	40c

(((No change to footnotes)))

For SI: 1 pound per square foot = 0.0479 kPa, 1 square inch = 645 mm, 1 pound = 4.45 N
a.	Elevated garage floors shall be capable of supporting a 2,000 pound load applied over a 20 square-inch area.
b.	Uninhabitable attics without storage are those where the clear height between joists and rafters is not more than 42 inches, or where there are not two or more adjacent trusses with web configurations capable of accommodating an assumed rectangle 42 inches in height by 24 inches in width, or greater, within the plane of the trusses. This live load need not be assumed to act concurrently with any other live load requirements.
c.	Individual stair treads shall be designed for the uniformly distributed live load or a 300 pound concentrated load acting over an area of 4 square inches, whichever produces the greater stresses.
d.	A single concentrated load applied in any direction at any point along the top.
e.	See Section R507.1 for decks attached to exterior walls.
f.	Guard in-fill components (all those except the handrail), balusters and panel fillers shall be designed to withstand a horizontally applied normal load of 50 pounds on an area equal to 1 square foot. This load need not be assumed to act concurrently with any other live load requirement.
g.	Uninhabitable attics with limited storage are those where the clear height between joists and rafters is 42 inches or greater, or where there are two or more adjacent trusses with web configurations capable of accommodating an assumed rectangle 42 inches in height by 24 inches in width, or greater, within the plane of the trusses. The live load need only be applied to those portions of the joists or truss bottom chords where all of the following conditions are met:
g.1.	The attic area is accessed from an opening not less than 20 inches in width by 30 inches in length that is located where the clear height in the attic is not less than 30 inches.
g.2.	The slopes of the joists or truss bottom chords are not greater than 2 inches vertical to 12 units horizontal.
g.3.	Required insulation depth is less than the joist or truss bottom chord member depth. The remaining portions of the joists or truss bottom chords shall be designed for a uniformly distributed concurrent live load of not less than 10 pounds per square foot.
h.	Glazing used in handrail assemblies and guards shall be designed with a safety factor of 4. The safety factor shall be applied to each of the concentrated loads applied to the top of the rail, and to the load on the in-fill components. These loads shall be determined independent of one another, and loads are assumed not to occur with any other live load.
i.	Where structural tables in Section R507 only specify snow loads, the values corresponding to 70 psf snow loads shall be used.

AMENDATORY SECTION(Amending WSR 16-03-025, filed 1/11/16, effective 7/1/16)

WAC 51-51-0302Section R302—Fire-resistant construction.

((R302.1 Exterior walls. Construction, projections, openings and penetrations of exterior walls of dwellings and accessory buildings shall comply with Table R302.1(1); or dwellings equipped throughout with an automatic sprinkler system installed in accordance with Section P2904 shall comply with Table R302.1(2).

EXCEPTIONS:	1. Walls, projections, openings or penetrations in walls perpendicular to the line used to determine the fire separation distance.
	2. Walls of dwellings and accessory structures located on the same lot.
	3. Detached tool sheds and storage sheds, playhouses and similar structures exempted from permits are not required to provide protection based on location on the lot. Projections beyond the exterior wall shall not extend over the lot line.
	4. Detached garages accessory to a dwelling located within 2 feet (610 mm) of a lot line are permitted to have roof eave projections not exceeding 4 inches (102 mm).
	5. Foundation vents installed in compliance with this code are permitted.))

R302.2 Townhouses. Each townhouse shall be considered a separate building and shall be separated by one of the following methods:

1. A common 1-hour fire-resistance-rated wall assembly tested in accordance with ASTM E 119 or UL 263 and a fire sprinkler system in accordance with Section P2904 in both townhouses shall be provided. The cavity of the common wall shall not contain plumbing or mechanical equipment, ducts or vents. The wall shall be rated for fire exposure from both sides and shall extend to and be tight against the inside face of the exterior wall((s))sheathing and the underside of the roof sheathing. Penetrations of electrical outlet boxes shall be in accordance with Section R302.4.

2. A common 2-hour fire-resistance-rated wall assembly tested in accordance with ASTM E 119 or UL 263 shall be provided. The cavity of the common wall shall not contain plumbing or mechanical equipment, ducts or vents. The wall shall be rated for fire exposure from both sides and shall extend to and be tight against the inside face of the exterior wall((s))sheathing and the underside of the roof sheathing. Penetrations of electrical outlet boxes shall be in accordance with Section R302.4.

3. Two wall assemblies meeting the requirements of Section R302.1 for exterior walls shall be provided.

EXCEPTION:

Common walls are permitted to extend to and be tight against the interior side of the exterior walls if the cavity between the end of the common wall and the inside face of the exterior sheathing is filled, the full depth of the exterior wall, with a minimum of two, two-inch nominal thickness wood studs.

R302.2.1 Double walls. Each townhouse unit shall be separated from other townhouse units by two 1-hour fire-resistance-rated wall assemblies tested in accordance with ASTM E119, UL 263 or Section 703.3 of the International Building Code.

R302.2.2 Common walls. Common walls separating townhouse units shall be assigned a fire resistance rating in accordance with Item 1 or 2. The common wall shared by townhouse units shall be constructed without plumbing or mechanical equipment, ducts or vents in the cavity of the common wall. The wall shall be rated for fire exposure from both sides and shall extend to and be tight against exterior walls and the underside of the roof sheathing. Electrical installations shall be in accordance with Chapters 34 through 43. Penetrations of the membrane of common walls for electrical outlet boxes shall be in accordance with Section R302.4.

1. Where a fire sprinkler system in accordance with Section P2904 is provided, the common wall shall be not less than a 1-hour fire-resistance-rated wall assembly tested in accordance with ASTM E119, UL 263 or Section 703.3 of the International Building Code.

2. Where a fire sprinkler system in accordance with Section P2904 is not provided, the common wall shall be not less than a 2-hour fire-resistance-rated wall assembly tested in accordance with ASTM E119, UL 263 or Section 703.3 of the International Building Code.

R302.2.3Continuity. The fire-resistance-rated wall or assembly separating ((townhouses))townhouse units shall be continuous from the foundation to the underside of the roof sheathing, deck or slab. The fire-resistance rating shall extend the full length of the wall or assembly, including wall extensions through and separating attached enclosed accessory structures.

Where a story extends beyond the exterior wall of a story below:

1. The fire-resistance-rated wall or assembly shall extend to the outside edge of the upper story (see Figure R302.2(1)); or

2. The underside of the exposed floor-ceiling assembly shall be protected as required for projections in Section R302 (see Figure R302.2(2)).

R302.2.2 Common walls. Common walls separating townhouse units shall be assigned a fire-resistance rating in accordance with Item 1 or 2. The common wall shared by townhouse units shall be constructed without plumbing or mechanical equipment, ducts or vents in the cavity of the common wall. The wall shall be rated for fire exposure from both sides and shall extend to and be tight against exterior walls and the underside of the roof sheathing. Electrical installations shall be in accordance with Chapters 34 through 43. Penetrations of the membrane of common walls for electrical outlet boxes shall be in accordance with Section R302.4.

R302.2.3 Continuity. The fire-resistance-rated wall or assembly separating townhouse units shall be continuous from the foundation to the underside of the roof sheathing, deck or slab. The fire-resistance rating shall extend the full length of the wall or assembly, including wall extensions through and separating attached enclosed accessory structures.

R302.2.4 Parapets for townhouses. Parapets constructed in accordance with Section R302.2.5 shall be constructed for townhouses as an extension of exterior walls or common walls separating townhouse units in accordance with the following:

1. Where roof surfaces adjacent to the wall or walls are at the same elevation, the parapet shall extend not less than 30 inches (762 mm) above the roof surfaces.

2. Where roof surfaces adjacent to the wall or walls are at different elevations and the higher roof is not more than 30 inches (762 mm) above the lower roof, the parapet shall extend not less than 30 inches (762 mm) above the lower roof surface.

EXCEPTION:

A parapet is not required in the preceding two cases where the roof covering complies with a minimum Class C rating as tested in accordance with ASTM E108 or UL 790 and the roof decking or sheathing is of noncombustible materials or fire retardant-treated wood for a distance of 4 feet (1219 mm) on each side of the wall or walls, or one layer of 5/8-inch (15.9 mm) Type X gypsum board is installed directly beneath the roof decking or sheathing, supported by not less than nominal 2-inch (51 mm) ledgers attached to the sides of the roof framing members, for a distance of not less than 4 feet (1219 mm) on each side of the wall or walls and any openings or penetrations in the roof are not within 4 feet (1219 mm) of the common walls. Fire retardant-treated wood shall meet the requirements of Sections R802.1.5 and R803.2.1.2.

3. A parapet is not required where roof surfaces adjacent to the wall or walls are at different elevations and the higher roof is more than 30 inches (762 mm) above the lower roof. The common wall construction from the lower roof to the underside of the higher roof deck shall have not less than a 1-hour fire-resistance rating. The wall shall be rated for exposure from both sides.

OPTION ONE:

((R302.2.4))R302.2.6 Structural independence. Each ((individual))townhouseunit shall be structurally independent.

EXCEPTIONS:	1. Foundation supporting exterior walls or common walls.
	2. Structural roof and wall sheathing from each unit may be fastened to the common wall framing.
	3. Nonstructural wall and roof coverings.
	4. Flashing at termination of roof covering over common wall.
	5. Townhouse((s))units separated by a common wall as provided in Section R302.2, Item 1 or 2.
	6. Floor sheathing may fasten to the floor framing of both units.

OPTION TWO:

((R302.2.4 Structural independence. Each individual townhouse shall be structurally independent.

EXCEPTIONS:	1. Foundation supporting exterior walls or common walls.
	2. Structural roof and wall sheathing from each unit may be fastened to the common wall framing.
	3. Nonstructural wall and roof coverings.
	4. Flashing at termination of roof covering over common wall.
	5. Townhouse separated by a common wall as provided in Section R302.2, Item 1 or 2.
	6. Floor sheathing may fasten to the floor framing of both units.))

TABLE R302.1(1)

EXTERIOR WALLS

No Change to the Table

a	The fire-resistance rating shall be permitted to be reduced to 0 hours on the underside of the eave overhang if fireblocking is provided from the wall top plate to the underside of the roof sheathing.
b	The fire-resistance rating shall be permitted to be reduced to 0 hours on the underside of the rake overhang where ventilation openings are not installed in the rake overhang or in walls that are common to attic areas.

TABLE R302.1(2)

EXTERIOR WALLS - DWELLINGS WITH FIRE SPRINKLERS

No Change to the Table

a	For residential subdivisions where all dwellings are equipped throughout with an automatic sprinkler system installed in accordance with Section P2904, the fire separation distance for exterior walls not fire-resistance-rated and for fire-resistance-rated projections shall be permitted to be reduced to 0 feet, and unlimited unprotected openings and penetrations shall be permitted, where the adjoining lot provides an open setback yard that is 6 feet or more in width on the opposite side of the property line.
b	The fire-resistance rating shall be permitted to be reduced to 0 hours on the underside of the eave overhang if fireblocking is provided from the wall top plate to the underside of the roof sheathing.
c	The fire-resistance rating shall be permitted to be reduced to 0 hours on the underside of the rake overhang where ventilation openings are not installed in the rake overhang or in walls that are common to attic areas.

R302.3 Two-family dwellings. Wall and floor/ceiling assemblies separating dwelling units in two-family dwellings shall be constructed in accordance with Section R302.3.1 or R302.3.3. One accessory dwelling unit constructed within an existing dwelling unit need not be considered a separated dwelling unit in a two-family dwelling where all required smoke alarms, in the accessory dwelling unit and the primary dwelling unit, are interconnected in such a manner that the actuation of one alarm will activate all alarms in both the primary dwelling unit and the accessory dwelling unit.

R302.3.1Dwelling units in two-family dwellings shall be separated from each other by wall and floor assemblies having not less than a 1-hour fire-resistance rating where tested in accordance with ASTM E119, UL 263 or Section 703.3 of the International Building Code.

EXCEPTION:

A fire-resistance rating of 1/2 hour shall be permitted in buildings equipped throughout with an automatic sprinkler system installed in accordance with NFPA 13D.

R302.3.2 Fire-resistance-rated floor/ceiling and wall assemblies shall extend to and be tight against the exterior wall, and wall assemblies shall extend from the foundation to the underside of the roof sheathing.

EXCEPTION:

Wall assemblies need not extend through attic spaces where the ceiling is protected by not less than 5/8-inch (15.9 mm) Type X gypsum board, an attic draft stop constructed as specified in Section R302.12.1 is provided above and along the wall assembly separating the dwellings and the structural framing supporting the ceiling is protected by not less than 1/2-inch (12.7 mm) gypsum board or equivalent.

((R302.3.1))R302.3.3 Supporting construction. When floor assemblies are required to be fire-resistance rated by Section R302.3, the supporting construction of such assemblies shall have an equal or greater fire-resistance rating.

((EXCEPTION:

The supporting construction is not required to be fire-resistance rated where automatic fire sprinklers are installed in accordance with Appendix Q in both dwelling units.))

R302.4.1 Through penetrations. Through penetrations of fire-resistance-rated wall or floor assemblies shall comply with Section R302.4.1.1 or R302.4.1.2.

EXCEPTION:	Where the penetrating items are steel, ferrous or copper pipes, tubes or conduits, or fire sprinkler piping, the annular space shall be protected as follows:
	1. In concrete or masonry wall or floor assemblies, concrete, grout or mortar shall be permitted where installed to the full thickness of the wall or floor assembly or the thickness required to maintain the fire-resistance rating, provided that both of the following are complied with:
	1.1. The nominal diameter of the penetrating item is not more than 6 inches (152 mm).
	1.2. The area of the opening through the wall does not exceed 144 square inches (92900 mm2).
	2. The material used to fill the annular space shall prevent the passage of flame and hot gases sufficient to ignite cotton waste where subjected to ASTM E119 or UL 263 time temperature fire conditions under a positive pressure differential of not less than 0.01 inch of water (3 Pa) at the location of the penetration for the time period equivalent to the fire-resistance rating of the construction penetrated.

R302.13 Fire protection of floors. Floor assemblies that are not required elsewhere in this code to be fire-resistance rated, shall be provided with a 1/2-inch (12.7 mm) gypsum wallboard membrane, 5/8-inch (16 mm) wood structural panel membrane, or equivalent on the underside of the floor framing member. Penetrations or openings for ducts, vents, electrical outlets, lighting, devices, luminaires, wires, speakers, drainage, piping and similar openings or penetrations shall be permitted.

EXCEPTIONS:	1. Floor assemblies located directly over a space protected by an automatic sprinkler system in accordance with Appendix Q, NFPA 13D, or other approved equivalent sprinkler system.
	2. Floor assemblies located directly over a crawl space not intended for storage or fuel-fired appliances.
	3. Portions of floor assemblies shall be permitted to be unprotected when complying with the following:
	3.1. The aggregate area of the unprotected portions shall not exceed 80 square feet per story.
	3.2. Fire blocking in accordance with Section R302.11.1 is installed along the perimeter of the unprotected portion to separate the unprotected portion from the remainder of the floor assembly.
	4. Wood floor assemblies using dimensional lumber or structural composite lumber with a cross sectional area equal to or greater than 2-inch by 10-inch nominal dimension, or other approved floor assemblies demonstrating equivalent fire performance.

AMENDATORY SECTION(Amending WSR 16-03-025, filed 1/11/16, effective 7/1/16)

WAC 51-51-0303Section R303—Light, ventilation and heating.

R303.1 Natural light. All habitable rooms shall have an aggregate glazing area of not less than 8 percent of the floor area of such rooms.

EXCEPTION:

The glazed areas need not be installed in rooms where artificial light is provided capable of producing an average illumination of 6 footcandles (65 lux) over the area of the room at a height of 30 inches (762 mm) above the floor level.

R303.2 Adjoining rooms. For the purpose of determining light requirements, any room shall be considered as a portion of an adjoining room when at least one-half of the area of the common wall is open and unobstructed and provides an opening of not less than one-tenth of the floor area of the interior room but not less than 25 square feet (2.3 m2).

EXCEPTION:

Openings required for light shall be permitted to open into a sunroom with thermal isolation or a patio cover, provided there is an openable area between the adjoining room and the sunroom or a patio cover of not less than one-tenth of the floor area of the interior room but not less than 20 square feet (2 m2).

R303.3 Bathrooms. This section is not adopted.

R303.4 Minimum ventilation performance. Dwelling units shall be equipped with local exhaust and whole house ventilation systems designed and installed as specified in Section M1507.

EXCEPTION:

Additions with less than 500 square feet of conditioned floor area are exempt from the requirements in this Code for Whole House Ventilation Systems.

R303.5 Opening location. Outdoor intake and exhaust openings shall be located in accordance with Sections R303.5.1 and R303.5.2.

R303.5.1 Intake openings. Mechanical and gravity outdoor air intake openings shall be located a minimum of 10 feet (3048 mm) from any hazardous or noxious contaminant, such as vents, chimneys, plumbing vents, streets, alleys, parking lots and loading docks, except as otherwise specified in this code.

For the purpose of this section, the exhaust from dwelling unit toilet rooms, bathrooms and kitchens shall not be considered as hazardous or noxious.

EXCEPTIONS:	1. The 10-foot (3048 mm) separation is not required where the intake opening is located 3 feet (914 mm) or greater below the contaminant source.
	2. Vents and chimneys serving fuel-burning appliances shall be terminated in accordance with the applicable provisions of Chapters 18 and 24.
	3. Clothes dryer exhaust ducts shall be terminated in accordance with Section 1502.3.

R303.5.2 Exhaust openings. Exhaust air shall not be directed onto walkways. All exhaust ducts shall terminate outside the building. Terminal elements shall have at least the equivalent net free area of the duct work.

R303.5.2.1 Exhaust ducts. Exhaust ducts shall be equipped with back-draft dampers. All exhaust ducts in unconditioned spaces shall be insulated to a minimum of R-4.

R303.7 Interior stairway illumination. Interior stairways shall be provided with an artificial light source to illuminate the landings and treads. Stairway illumination shall receive primary power from the building wiring. The light source shall be capable of illuminating treads and landings to levels not less than 1 foot-candle (11 lux) measured at the center of treads and landings. There shall be a wall switch at each floor level to control the light source where the stairway has six or more risers.

EXCEPTION:

A switch is not required where remote, central or automatic control of lighting is provided.

R303.8 Exterior stairway illumination. Exterior stairways shall be provided with an artificial light source located at the top landing of the stairway. Stairway illumination shall receive primary power from the building wiring. Exterior stairways providing access to a basement from the outdoor grade level shall be provided with an artificial light source located at the bottom landing of the stairway.

R303.9 Required glazed openings. Required glazed openings shall open directly onto a street or public alley, or a yard or court located on the same lot as the building.

EXCEPTIONS:	1. Required glazed openings that face into a roofed porch where the porch abuts a street, yard or court are permitted where the longer side of the porch is not less than 65 percent unobstructed and the ceiling height is not less than 7 feet (2134 mm).
	2. Eave projections shall not be considered as obstructing the clear open space of a yard or court.
	3. Required glazed openings that face into the area under a deck, balcony, bay or floor cantilever are permitted where an unobstructed pathway of not less than 36 inches (914 mm) in height, 36 inches (914 mm) in width, and no greater than 60 inches (1524 mm) in length is provided and opens to a yard or court. The pathway shall be measured from the exterior face of the glazed opening, or if the glazed opening is in a window well, at the window well wall furthest from the exterior face of the glazed opening.

R303.10Required heating. When the winter design temperature in Table R301.2(1) is below 60°F (16°C), every dwelling unit shall be provided with heating facilities capable of maintaining a minimum room temperature of 68°F (20°C) at a point 3 feet (914 mm) above the floor and 2 feet (610 mm) from exterior walls in all habitable rooms at design temperature. The installation of one or more portable heaters shall not be used to achieve compliance with this section.

EXCEPTION:

Unheated recreational tents or yurts not exceeding 500 square feet provided it is not occupied as a permanent dwelling.

((R303.9.1))R303.10.1 Definitions. For the purposes of this section only, the following definitions apply.

DESIGNATED AREAS are those areas designated by a county to be an urban growth area in chapter 36.70A RCW and those areas designated by the U.S. Environmental Protection Agency as being in nonattainment for particulate matter.

SUBSTANTIALLY REMODELED means any alteration or restoration of a building exceeding 60 percent of the appraised value of such building within a 12 month period. For the purpose of this section, the appraised value is the estimated cost to replace the building and structure in kind, based on current replacement costs.

((R303.9.2))R303.10.2 Primary heating source. Primary heating sources in all new and substantially remodeled buildings in designated areas shall not be dependent upon wood stoves.

((R303.9.3))R303.10.3 Solid fuel burning devices. No new or used solid fuel burning device shall be installed in new or existing buildings unless such device is U.S. Environmental Protection Agency certified or exempt from certification by the United States Environmental Protection Agency and conforms with RCW 70.94.011, 70.94.450, 70.94.453, and 70.94.457.

EXCEPTIONS:	1. Wood cook stoves.
	2. Antique wood heaters manufactured prior to 1940.

AMENDATORY SECTION(Amending WSR 16-03-025, filed 1/11/16, effective 7/1/16)

WAC 51-51-0308((Section R308—Glazing.))Reserved.

((R308.4.4 Glazing in guards and railings. Glazing in guards and railings, including structural baluster panels and nonstructural in-fill panels, regardless of area or height above a walking surface shall be considered to be a hazardous location.

R308.4.4.1 Structural glass baluster panels. Guards with structural glass baluster panels shall be installed with an attached top rail or handrail. The top rail or handrail shall be supported by a minimum of three glass baluster panels, or shall be otherwise supported to remain in place should one glass baluster panel fail.

EXCEPTION:

An attached top rail or handrail is not required where the glass baluster panels are laminated glass with two or more glass plies of equal thickness and of the same glass type.))

NEW SECTION

WAC 51-51-03100Section 3100—Emergency escape and rescue openings.

R3100.1 Emergency escape and rescue opening required. Basements, habitable attics and every sleeping room shall have not less than one operable emergency escape and rescue opening. Where basements contain one or more sleeping rooms, an emergency escape and rescue opening shall be required in each sleeping room. Emergency escape and rescue openings shall open directly into a public way, or to a yard or court providing an unobstructed path with a width of not less than 36 inches (914 mm) that opens to a public way.

EXCEPTIONS:	1. Storm shelters and basements used only to house mechanical equipment not exceeding a total floor area of 200 square feet (18.58 m).
	2. Where the dwelling unit or townhouse unit is equipped with an automatic sprinkler system installed in accordance with Section P2904, sleeping rooms in basements shall not be required to have emergency escape and rescue openings provided that the basement has one of the following:
	2.1. One means of egress complying with Section R311 and one emergency escape and rescue opening.
	2.2. Two means of egress complying with Section R311.

R3100.1.1 Operational constraints and opening control devices. Emergency escape and rescue openings shall be operational from the inside of the room without the use of keys, tools, or special knowledge. Window opening control devices on windows serving as a required emergency escape and rescue opening shall be not more than 70 inches (177.8 cm) above the finished floor and shall comply with ASTM F2090.

R3100.2.4 Emergency escape and rescue openings under decks and porches. Emergency escape and rescue openings installed under decks and porches shall be fully openable and provided with an unobstructed pathway of not less than 36 inches (914 mm) in height, 36 inches (914 mm) in width, and no greater than 60 inches (1524 mm) in length that opens to a yard or court. The pathway shall be measured from the exterior face of the glazed opening, or if the glazed opening is in a window well, at the window well wall furthest from the exterior face of the glazed opening.

AMENDATORY SECTION(Amending WSR 10-03-098, filed 1/20/10, effective 7/1/10)

WAC 51-51-0311Section R311—Means of egress.

R311.4 Vertical egress. Egress from habitable levels including habitable attics and basements not provided with an egress door in accordance with Section R311.2 shall be by ramp in accordance with Section R311.8 or a stairway in accordance with Section R311.7.

EXCEPTION:

Stairs or ladders within an individual dwelling unit used for access to areas of 200 square feet (18.6 m2) or less, and not containing the primary bathroom or kitchen.

R311.7.3 Vertical rise. A flight of stairs shall not have a vertical rise larger than 12 feet 7 inches (3835 mm) between floor levels or landings.

AMENDATORY SECTION(Amending WSR 16-03-025, filed 1/11/16, effective 7/1/16)

WAC 51-51-0313Section R313—Automatic fire sprinkler systems.

((This section is not adopted.))R313.1 Townhouse automatic fire sprinkler systems. An automatic residential fire sprinkler system shall be installed in townhouse units.

EXCEPTIONS:	1. An automatic residential fire sprinkler system shall not be required where additions or alterations are made to existing townhouse units that do not have an automatic residential fire sprinkler system installed.
	2. Townhouse buildings containing no more than four townhouse units.

R313.1.1 Design and installation. Automatic residential fire sprinkler systems for townhouses shall be designed and installed in accordance with Section P2904 or NFPA 13D.

R313.2 One- and two-family dwellings automatic fire sprinkler system. This section is not adopted.

AMENDATORY SECTION(Amending WSR 16-03-025, filed 1/11/16, effective 7/1/16)

WAC 51-51-0314Section R314—Smoke alarms and heat detection.

R314.1 General. Smoke alarms, heat detectors, and heat alarms shall comply with NFPA 72 and this section.

R314.1.1 Listings. Smoke alarms shall be listed in accordance with UL 217. Heat detectors and heat alarms shall be listed for the intended application. Combination smoke and carbon monoxide alarms shall be listed in accordance with UL 217 and UL 2034.

R314.2 Where required. Smoke alarms, heat detectors, and heat alarms shall be provided in accordance with this section.

R314.2.1 New construction. Smoke alarms shall be provided in dwelling units. A heat detector or heat alarm shall be provided in new attached garages.

R314.2.2 Alterations, repairs and additions. Where alterations, repairs or additions requiring a permit occur, ((or)) where one or more sleeping rooms are added or created in existing dwellings, ((the individual))or where an accessory dwelling unit is created within an existing dwelling unit, eachdwelling unit shall be equipped with smoke alarms located as required for new dwellings.

EXCEPTIONS:	1. Work involving the exterior surfaces of dwellings, such as the replacement of roofing or siding, the addition or replacement of windows or doors, or the addition of a porch or deck are exempt from the requirements of this section.
	2. Installation, alteration or repairs of plumbing, electrical or mechanical systems are exempt from the requirements of this section.

R314.2.3 New attached garages. A heat detector or heat alarm rated for the ambient outdoor temperatures and humidity shall be installed in new garages that are attached to or located under new and existing dwellings. Heat detectors and heat alarms shall be installed in a central location and in accordance with the manufacturer's instructions.

EXCEPTION:

Heat detectors and heat alarms shall not be required in dwellings without commercial power.

R314.3 Location. Smoke alarms shall be installed in the following locations:

1. In each sleeping room or sleeping loft.

2. Outside each separate sleeping area in the immediate vicinity of the bedrooms.

3. On each additional story of the dwelling, including basements and habitable attics but not including crawl spaces and uninhabitable attics. In dwellings or dwelling units with split levels and without an intervening door between the adjacent levels, a smoke alarm installed on the upper level shall suffice for the adjacent lower level provided that the lower level is less than one full story below the upper level.

4. Smoke alarms shall be installed not less than 3 feet (914 mm) horizontally from the door or opening of a bathroom that contains a bathtub or shower unless this would prevent placement of a smoke alarm required by Section R314.3.

5. In napping areas in a family home child care.

R314.3.1 Installation near cooking appliances. Smoke alarms shall not be installed in the following locations unless this would prevent placement of a smoke alarm in a location required by Section R314.3.

1. Ionization smoke alarms shall not be installed less than 20 feet (6096 mm) horizontally from a permanently installed cooking appliance.

2. Ionization smoke alarms with an alarm-silencing switch shall not be installed less than 10 feet (3048 mm) horizontally from a permanently installed cooking appliance.

3. Photoelectric smoke alarms shall not be installed less than 6 feet (1828 mm) horizontally from a permanently installed cooking appliance.

R314.4 Interconnection. Where more than one smoke alarm is required to be installed within an individual dwelling unit in accordance with Section R314.2, the alarm devices shall be interconnected in such a manner that the actuation of one alarm will activate all of the alarms in the individual dwelling unit. Where an accessory dwelling unit is created within an existing dwelling unit all required smoke alarms, in the accessory dwelling unit and the primary dwelling unit, shall be interconnected in such a manner that the actuation of one alarm will activate all alarms in both the primary dwelling unit and the accessory dwelling unit. Physical interconnection of smoke alarms shall not be required where listed wireless alarms are installed and all alarms sound upon activation of one alarm.

EXCEPTION:

Smoke alarms and alarms installed to satisfy Section R314.4.1 shall not be required to be interconnected to existing smoke alarms where such existing smoke alarms are not interconnected or where such new smoke alarm or alarm is not capable of being interconnected to the existing smoke alarms.

R314.4.1 Heat detection interconnection. Heat detectors and heat alarms shall be connected to an alarm or a smoke alarm that is installed in the dwelling. Alarms and smoke alarms that are installed for this purpose shall be located in a hallway, room, or other location that will provide occupant notification.

R314.6 Power source. Smoke alarms, heat alarms, and heat detectors shall receive their primary power from the building wiring where such wiring is served from a commercial source and, where primary power is interrupted, shall receive power from a battery. Wiring shall be permanent and without a disconnecting switch other than those required for overcurrent protection.

EXCEPTIONS:	1. Smoke alarms shall be permitted to be battery operated where installed in buildings without commercial power.
	2. Smoke alarms installed in accordance with Section R314.2.2 shall be permitted to be battery powered.

AMENDATORY SECTION(Amending WSR 16-03-025, filed 1/11/16, effective 7/1/16)

WAC 51-51-0315Section R315—Carbon monoxide alarms.

R315.1General. Carbon monoxide alarms shall comply with Section R315.

R315.1.1 Listings. Carbon monoxide alarms shall be listed in accordance with UL 2034. Combination carbon monoxide and smoke alarms shall be listed in accordance with UL 2034 and UL 217.

R315.2 Where required. Carbon monoxide alarms shall be provided in accordance with Sections R315.2.1 and R315.2.2.

R315.2.1 New construction. For new construction, an approved carbon monoxide alarm shall be installed outside of each separate sleeping area in the immediate vicinity of the bedrooms in dwelling units and on each level of the dwelling in accordance with the manufacturer's recommendation.

R315.2.2 Alterations, repairs, and additions. Existing dwellings shall be equipped with carbon monoxide alarms in accordance with Section R315.2.1. An inspection will occur where alterations, repairs, or additions requiring a permit occur, or where one or more sleeping rooms are added or created.

EXCEPTIONS:	1. Work involving only the exterior surfaces of dwellings, such as the replacement of roofing or siding, or the addition or replacement of windows or doors, or the addition of a porch or deck, is exempt from the inspection requirements of this section.
	2. Installation, alteration or repairs of nonfuel burning plumbing or mechanical systems or electrical systems are exempt from the inspection requirements of this section.
	3. Owner-occupied single-family residences legally occupied before July 26, 2009. RCW 19.27.530 (2)(b).

R315.3 Location. Carbon monoxide alarms in dwelling units shall be installed outside of each separate sleeping area in the immediate vicinity of the bedrooms and on each level of the dwelling and in accordance with the manufacturer's recommendations. Where a fuel burning appliance is located within a bedroom or its attached bathroom, a carbon monoxide alarm shall be installed within the bedroom.

R315.4 Combination alarms. Combination carbon monoxide and smoke alarms shall be permitted to be used in lieu of carbon monoxide alarms.

AMENDATORY SECTION(Amending WSR 16-03-025, filed 1/11/16, effective 7/1/16)

WAC 51-51-03240Section R324—Solar energy systems.

((R324.1 General. Solar energy systems shall comply with the provisions of this section.

R324.2 Solar thermal systems. Solar thermal systems shall be designed and installed in accordance with Chapter 23 and the International Fire Code.))

R324.3 Photovoltaic systems. Installation, modification, or alteration of solar photovoltaic power systems shall comply with this section and the International Fire Code. Section R104.11 alternate materials and methods of this code shall be considered when approving the installation of solar photovoltaic power systems. Photovoltaic systems shall be designed and installed in accordance with Sections R324.3.1 through R324.6 and chapter 19.28 RCW. Inverters shall be listed and labeled in accordance with UL 1741. Systems connected to the utility grid shall use inverters listed for utility interaction.

EXCEPTION:

Detached, nonhabitable Group U structures shall not be subject to the requirements of this section for structural and fire safety.

((R324.3.1 Equipment listing. Photovoltaic panels and modules shall be listed and labeled in accordance with UL 1703.))

R324.4 Rooftop-mounted photovoltaic systems. Rooftop-mounted photovoltaic panel systems installed on or above the roof covering shall be designed and installed in accordance with Section 907.

EXCEPTIONS:	The roof structure shall be deemed adequate to support the load of the rooftop solar photovoltaic system if all of the following requirements are met:
	1. The solar photovoltaic panel system shall be designed for the wind speed of the local area, and shall be installed per the manufacturer's specifications.
	2. The ground snow load does not exceed 70 pounds per square foot.
	3. The total dead load of modules, supports, mountings, raceways, and all other appurtenances weigh no more than 4 pounds per square foot.
	4. Photovoltaic modules are not mounted higher than 18 inches above the surface of the roofing to which they are affixed.
	5. Supports for solar modules are to be installed to spread the dead load across as many roof-framing members as needed, so that no point load exceeds 50 pounds.

((R324.4.1 Roof load. Portions of roof structures not covered with photovoltaic panel systems shall be designed for dead loads and roof loads in accordance with Sections R301.4 and R301.6. Portions of roof structures covered by photovoltaic panel systems shall be designed for the following load cases:

1. Dead load (including photovoltaic panel weight) plus snow load in accordance with Table R301.2(1).

2. Dead load (excluding photovoltaic panel weight), plus roof live load or snow load, whichever is greater, in accordance with Section R301.6.

R324.4.2 Wind resistance. Rooftop-mounted photovoltaic panel or module systems and their supports shall be designed to resist the component and cladding loads specified in Table R301.2(2), adjusted for height and exposure in accordance with Table R301.2(3).

R324.5 Building-integrated photovoltaic systems. Building-integrated photovoltaic systems that serve as roof coverings shall be designed and installed in accordance with Section R905.))

R324.5.1 Photovoltaic shingles. Photovoltaic shingles shall comply with Section R905.16.

R324.6 ((Ground-mounted photovoltaic systems. Ground-mounted photovoltaic systems shall be designed and installed in accordance with Section R301.

R324.7)) This section is not adopted.

AMENDATORY SECTION(Amending WSR 16-03-025, filed 1/11/16, effective 7/1/16)

WAC 51-51-0325Section R325—((Adult family homes.))Mezzanines.

((SECTION R325

ADULT FAMILY HOMES

R325.1 General. This section shall apply to all newly constructed adult family homes and all existing single family homes being converted to adult family homes. This section shall not apply to those adult family homes licensed by the state of Washington department of social and health services prior to July 1, 2001.

R325.2Reserved.

R325.3 Sleeping room classification. Each sleeping room in an adult family home shall be classified as:

1. Type S - Where the means of egress contains stairs, elevators or platform lifts.

2. Type NS1 - Where one means of egress is at grade level or a ramp constructed in accordance with R325.9 is provided.

3. Type NS2 - Where two means of egress are at grade level or ramps constructed in accordance with R325.9 are provided.

R325.4 Types of locking devices and door activation. All bedroom and bathroom doors shall be openable from the outside when locked.

Every closet shall be readily openable from the inside.

Operable parts of door handles, pulls, latches, locks and other devices installed in adult family homes shall be operable with one hand and shall not require tight grasping, pinching or twisting of the wrist. Pocket doors shall have graspable hardware available when in the closed or open position.

The force required to activate operable parts shall be 5.0 pounds (22.2 N) maximum. Required exit doors shall have no additional locking devices.

Required exit door hardware shall unlock inside and outside mechanisms when exiting the building allowing reentry into the adult family home without the use of a key, tool or special knowledge.

R325.5 Smoke and carbon monoxide alarm requirements. All adult family homes shall be equipped with smoke and carbon monoxide alarms installed as required in Sections R314 and R315.1. Alarms shall be installed in such a manner so that the detection device warning is audible from all areas of the dwelling upon activation of a single alarm.

R325.6 Escape windows and doors. Every sleeping room shall be provided with emergency escape and rescue windows as required by Section R310. No alternatives to the sill height such as steps, raised platforms or other devices placed by the openings will be approved as meeting this requirement.

R325.7 Fire apparatus access roads and water supply for fire protection. Adult family homes shall be served by fire apparatus access roads and water supplies meeting the requirements of the local jurisdiction.

R325.8 Grab bar general requirements. Where facilities are designated for use by adult family home clients, grab bars for water closets, bathtubs and shower stalls shall be installed according to this section.

R325.8.1 Grab bar cross section. Grab bars with a circular cross section shall have an outside diameter of 1 1/4 inches minimum and 2 inches maximum. Grab bars with noncircular cross section shall have a cross section dimension of 2 inches maximum and a perimeter dimension of 4 inches minimum and 4 5/8 inches maximum.

R325.8.2 Grab bar installation. Grab bars shall have a spacing of 1 1/2 inches between the wall and the bar. Projecting objects, control valves and bathtub or shower stall enclosure features above, below and at the ends of the grab bar shall have a clear space of 1 1/2 inches to the grab bar.

EXCEPTION:

Swing-up grab bars shall not be required to meet the 1 1/2 inch spacing requirement.

Grabs bars shall have a structural strength of 250 pounds applied at any point on the grab bar, fastener, mounting device or supporting structural member. Grab bars shall not be supported directly by any residential grade fiberglass bathing or showering unit. Acrylic bars found in bathing units shall be removed.

Fixed position grab bars, when mounted, shall not rotate, spin or move and have a graspable surface finish.

R325.8.3 Grab bars at water closets. Water closets shall have grab bars mounted on both sides. Grab bars can be a combination of fixed position and swing-up bars. Grab bars shall meet the requirements of R325.8. Grab bars shall mount between 33 inches and 36 inches above floor grade. Centerline distance between grab bars, regardless of type used, shall be between 25 inches minimum and 30 inches maximum.

R325.8.3.1 Fixed position grab bars. Fixed position grab bars shall be a minimum of 36 inches in length and start 12 inches from the rear wall.

R325.8.3.2 Swing-up grab bars. Swing-up grab bars shall be a minimum of 28 inches in length from the rear wall.

R325.8.4 Grab bars at bathtubs. Horizontal and vertical grab bars shall meet the requirements of R325.8.

R325.8.4.1 Vertical grab bars. Vertical grab bars shall be a minimum of 18 inches long and installed at the control end wall and head end wall. Grab bars shall mount within 4 inches of the exterior of the bath tub edge or within 4 inches within the bath tub. The bottom end of the bar shall start between 36 inches and 42 inches above floor grade.

EXCEPTION:

The required vertical grab bar can be substituted with a floor to ceiling grab bar meeting the requirements of R325.8 at the control end and head end entry points.

R325.8.4.2 Horizontal grab bars. Horizontal grab bars shall be provided at the control end, head end, and the back wall within the bathtub area. Grab bars shall be mounted between 33 inches and 36 inches above floor grade. Control end and head end grab bars shall be 24 inches minimum in length. Back wall grab bar shall be 36 inches minimum in length.

R325.8.5 Grab bars at shower stalls. Where shower stalls are provided to meet the requirements for bathing facilities, grab bars shall meet the requirements of R325.8.

EXCEPTION:

Shower stalls with permanent built-in seats are not required to have vertical or horizontal grab bars at the seat end wall. A vertical floor to ceiling grab bar shall be installed within 4 inches of the exterior of the shower aligned with the nose of the built-in seat.

R325.8.5.1 Vertical grab bars. Vertical grab bars shall be 18 inches minimum in length and installed at the control end wall and head end wall. Vertical bars shall be mounted within 4 inches of the exterior of the shower stall or within 4 inches inside the shower stall. The bottom end of vertical bars mount between 36 inches and 42 inches above floor grade.

R325.8.5.2 Horizontal grab bars. Horizontal grab bars shall be installed on all sides of the shower stall mounted between 33 inches and 36 inches above the floor grade. Horizontal grab bars shall be a maximum of 6 inches from adjacent walls. Horizontal grab bars shall not interfere with shower control valves.

R325.9 Ramps. All interior and exterior ramps, when provided, shall be constructed in accordance with Section R311.8 with a maximum slope of 1 vertical to 12 horizontal. The exception to R311.8.1 is not allowed for adult family homes. Handrails shall be installed in accordance with R325.9.1.

R325.9.1 Handrails for ramps. Handrails shall be installed on both sides of ramps between the slope of 1 vertical to 12 horizontal and 1 vertical and 20 horizontal in accordance with R311.8.3.1 through R311.8.3.3.

R325.10 Stair treads and risers. Stair treads and risers shall be constructed in accordance with R311.7.5. Handrails shall be installed in accordance with R325.10.1.

R325.10.1 Handrails for treads and risers. Handrails shall be installed on both sides of treads and risers numbering from one riser to multiple risers. Handrails shall be installed in accordance with R311.7.8.1 through R311.7.8.4.

R325.11 Shower stalls. Where provided to meet the requirements for bathing facilities, the minimum size of shower stalls for an adult family home shall be 30 inches deep by 48 inches long.))

R325.6 Habitable attic. A habitable attic shall be considered to be a story above grade plane.

EXCEPTION:

Where located above the third story, an automatic sprinkler system complying with P2904 or NFPA 13D shall be installed throughout the dwelling or townhouse that includes the habitable attic.

AMENDATORY SECTION(Amending WSR 13-04-068, filed 2/1/13, effective 7/1/13)

WAC 51-51-0326Section R326—((Family home child care.))Sleeping lofts.

((R326 Family home child care. For family home child care with more than six children, each floor level used for family child care purposes shall be served by two remote means of egress. Exterior exit doors shall be operable from the inside without the use of keys or any special knowledge or effort.

Basements located more than 4 feet below grade level shall not be used for family home child care unless one of following conditions exist:

1. Stairways from the basement open directly to the exterior of the building without entering the first floor; or

2. One of the two required means of egress discharges directly to the exterior from the basement level, and a self-closing door is installed at the top or bottom of the interior stair leading to the floor above; or

3. One of the two required means of egress is an operable window or door, approved for emergency escape or rescue, that opens directly to a public street, public alley, yard or exit court; or

4. A residential sprinkler system is provided throughout the entire building in accordance with NFPA 13d.

Floors located more than 4 feet above grade level shall not be occupied by children in family home child care.

EXCEPTIONS:	1. Use of toilet facilities while under supervision of an adult staff person.
	2. Family home child care may be allowed on the second story if one of the following conditions exists:
	2.1 Stairways from the second story open directly to the exterior of the building without entering the first floor; or
	2.2 One of the two required means of egress discharges directly to the exterior from the second story level, and a self-closing door is installed at the top or bottom of the interior stair leading to the floor below; or
	2.3 A residential sprinkler system is provided throughout the entire building in accordance with NFPA 13d.

Every sleeping or napping room in a family home child care shall have at least one operable window for emergency rescue.

EXCEPTION:

Sleeping or napping rooms having doors leading to two separate means of egress, or a door leading directly to the exterior of the building.

Rooms or spaces containing a commercial-type cooking kitchen, boiler, maintenance shop, janitor closet, laundry, woodworking shop, flammable or combustible storage, or painting operation shall be separated from the family home child care area by at least one-hour fire-resistive construction.

EXCEPTION:

A fire-resistive separation shall not be required where the food preparation kitchen contains only a domestic cooking range, and the preparation of food does not result in the production of smoke or grease laden vapors.))

R326.1 General.Sleeping lofts shall comply with Sections R326 through R326.5.

R326.2 Sleeping loft area and dimensions.Sleeping lofts shall meet the minimum area and dimension requirements of Sections R326.2.1 through R326.2.3.

R326.2.1 Area.Sleeping lofts shall have a floor area of not less than 35 square feet (3.25 m2) and less than 70 square feet (6.5 m2).

R326.2.2 Minimum horizontal dimensions.Sleeping lofts shall be not less than 5 feet (1524 mm) in any horizontal dimension.

R326.2.3 Height effect on sleeping loft area. Portions of a sleeping loft with a sloped ceiling measuring less than 3 feet (914 mm) from the finished floor to the finished ceiling shall not be considered as contributing to the minimum required area for the loft but shall contribute to the maximum allowable area.

EXCEPTION:

Under gable roofs with a minimum slope of 6 units vertical in 12 units horizontal (50-percent slope), portions of a sleeping loft with a sloped ceiling measuring less than 16 inches (406 mm) from the finished floor to the finished ceiling shall not be considered as contributing to the minimum required area for the sleeping loft but shall contribute to the maximum allowable area.

R326.3 Sleeping loft access and egress. The access to and primary egress from sleeping lofts shall be of any type described in Sections R326.3.1 through R326.3.5 and shall meet the sleeping loft where the sleeping loft's ceiling height is not less than 3 feet (914 mm) along the entire width of the access and egress component.

R326.3.1 Stairways. Stairways accessing sleeping lofts shall comply with Sections R326.3.1.1 through R326.3.1.7.

R326.3.1.1 Headroom. The headroom above the sleeping loft access and egress shall be not less than 6 feet 2 inches (1880 mm), as measured vertically, from a sloped line connecting the tread, landing, or landing platform nosing's in the center of their width, and vertically from the landing or landing platform along the center of its width.

R326.3.1.2 Width. Stairways accessing a sleeping loft shall not be less than 17 inches (432 mm) in clear width at or above the handrail. The width below the handrail shall be not less than 20 inches (508 mm).

R326.3.1.3 Treads and risers. Risers for stairs accessing a sleeping loft shall be not less than 7 inches (178 mm) and not more than 12 inches (305 mm) in height. Tread depth and riser height shall be calculated in accordance with one of the following formulas:

1. Under gable roofs with a minimum slope of 6 units vertical in 12 units horizontal (50-percent slope), portions of a sleeping loft with a sloped ceiling measuring less than 16 inches (406 mm) from the finished floor to the finished ceiling shall not be considered as contributing to the minimum required area for the sleeping loft but shall contribute to the maximum allowable area.

2. The tread depth shall be 20 inches (508 mm) minus four-thirds of the riser height.

R326.3.1.4 Landings. Intermediate landings and landings at the bottom of stairways shall comply with Section R311.7.6, except that the depth in the direction of travel shall be not less than 24 inches (508 mm).

R326.3.1.5 Landing platforms. The top tread and riser of stairways accessing sleeping lofts shall be constructed as a landing platform where the loft ceiling height is less than 6 feet 2 inches (1880 mm) where the stairway meets the sleeping loft. The landing platform shall be not less than 18 inches (508 mm) in width and in depth measured horizontally from and perpendicular to the nosing of the landing platform. The landing platform riser height to the edge of the sleeping loft floor, shall not be greater than 18 inches (406 to 457 mm) in height.

R326.3.1.6 Handrails. Handrails shall comply with Section R311.7.8.

R326.3.1.7 Stairway guards. Guards at open sides of stairways, landings, and landing platforms shall comply with Section R312.1.

R326.3.2 Ladders. Ladders accessing sleeping lofts shall comply with Sections R326.3.2.1 and R326.3.2.2.

R326.3.2.1 Size and capacity. Ladders accessing sleeping lofts shall have a rung width of not less than 12 inches (305 mm), and 10-inch (254 mm) to 14-inch (356 mm) spacing between rungs. Ladders shall be capable of supporting a 300 pound (136 kg) load on any rung. Rung spacing shall be uniform within 3/8 inch (9.5 mm).

R326.3.2.2 Incline. Ladders shall be installed at 70 to 80 degrees from horizontal.

R326.3.3 Alternating tread devices. Alternating tread devices accessing sleeping lofts shall comply with Sections R311.7.11.1 and R311.7.11.2. The clear width at and below the handrails shall be not less than 20 inches (508 mm).

R326.3.4 Ships ladders. Ships ladders accessing sleeping lofts shall comply with Sections R311.7.12.1 and R311.7.12.2. The clear width at and below handrails shall be not less than 20 inches (508 mm).

R326.4 Sleeping loft guards.Sleeping loft guards shall be located along the open side(s) of sleeping lofts. Sleeping loft guards shall be not less than 36 inches (914 mm) in height or one-half of the clear height to the ceiling, whichever is less. Sleeping loft guards shall comply with Section R312.1.3 and Table R301.5 for their components.

R326.5 Emergency escape and rescue openings. An egress roof access window shall be installed in each sleeping loft and shall be deemed to meet the requirements of Section R310 where installed such that the bottom of the opening is not more than 44 inches (1118 mm) above the sleeping loft floor, provided the egress roof access window complies with the minimum opening area requirements of Section R310.2.1.

AMENDATORY SECTION(Amending WSR 07-01-090, filed 12/19/06, effective 7/1/07)

WAC 51-51-0327Section R327—((Protection against radon.))Swimming pools, spas, and hot tubs.

((R327.1 Protection Against Radon. The radon control provisions of Appendix F of this code shall apply to buildings constructed in High Radon Potential Counties (zone 1) designated in Table AF101 (1). The radon control provisions of Appendix F of this code shall also apply to all buildings constructed using the provisions of Section R408.3 Unvented crawl space compliance method.))R327.1 General. The design and construction of swimming pools, spas, and other aquatic recreation facilities shall comply with the 2018 International Swimming Pool and Spa Code, if the facility is one of the following:

1. For the sole use of residents and invited guests at a single-family dwelling;

2. For the sole use of residents and invited guests of a duplex owned by the residents; or

3. Operated exclusively for physical therapy or rehabilitation and under the supervision of a licensed medical practitioner.

AMENDATORY SECTION(Amending WSR 16-03-025, filed 1/11/16, effective 7/1/16)

WAC 51-51-0328Section R328—((Mezzanines.))Energy storage systems.

((R328.1 General. Mezzanines shall comply with Section R328.

R328.2 Mezzanines. The clear height above and below mezzanine floor construction shall be not less than 7 feet (2134 mm).

R328.3 Area limitation. The aggregate area of a mezzanineor mezzanines shall be not greater than one-third of the floor area of the room or space in which they are located. The enclosed portion of a room shall not be included in a determination of the floor area of the room in which the mezzanine is located.

R328.4 Means of egress. The means of egress for mezzanines shall comply with the applicable provisions of Section R311.

R328.5 Openness. Mezzanines shall be open and unobstructed to the room in which they are located except for walls not more than 42 inches (1067 mm) in height, columns and posts.

EXCEPTIONS:	1. Mezzanines or portions thereof are not required to be open to the room in which they are located, provided that the aggregate floor area of the enclosed space is not greater than 10 percent of the mezzanine area.
	2. Mezzanines that are no more than two stories above grade plane and equipped throughout with an automatic sprinkler system in accordance with NFPA 13R, NFPA 13D or Appendix S, and having two or more means of egress, shall not be required to be open to the room in which the mezzanine is located.))

R328.1 General.Energy storage systems (ESS) shall comply with the provisions of this section.

R328.2 Equipment listings. ESS shall be listed and labeled for residential use in accordance with UL 9540.

EXCEPTIONS:	1. Where approved, repurposed unlisted battery systems from electric vehicles are allowed to be installed outdoors or in detached sheds located not less than 5 feet (1524 mm) from exterior walls, property lines and public ways.
	2. Battery systems that are an integral part of an electric vehicle are allowed provided that the installation complies with Section 625.48 of NFPA 70.
	3. Battery systems less than 1 kWh (3.6 megajoules).

R328.3 Installation. ESS shall be installed in accordance with the manufacturer's instructions and their listing, if applicable, and shall not be installed within the habitable space of a dwelling unit.

R328.4 Electrical installation. ESS shall be installed in accordance with NFPA 70. Inverters shall be listed and labeled in accordance with UL 1741 or provided as part of the UL 9540 listing. Systems connected to the utility grid shall use inverters listed for utility interaction.

R328.5 Ventilation. Indoor installations of ESS that include batteries that produce hydrogen or other flammable gases during charging shall be provided with ventilation in accordance with Section M1307.4.

R328.6 Commissioning. ESS shall be commissioned as follows:

1. Verify that the system is installed in accordance with the approved plans and manufacturer's instructions and is operating properly.

2. Provide a copy of the manufacturer's installation, operation, maintenance, and decommissioning instructions provided with the listed system.

3. Provide a label on the installed system containing the contact information for the qualified maintenance and service providers.

R328.6.1 Installation prior to closing. Where the system is installed in a one- or two-family dwelling or townhouse that is owned by the builder and has yet to be sold, commissioning shall be conducted as outlined in Section R327.6, and the builder shall then transfer the required information in Section R327.6 to the homeowner when the property is transferred to the owner at the closing.

R328.7 Protection from impact. ESS installed in a location subject to vehicle damage shall be protected by approved barriers.

AMENDATORY SECTION(Amending WSR 16-03-025, filed 1/11/16, effective 7/1/16)

WAC 51-51-0329Section R329—((Swimming pools, spas, and hot tubs.))Adult family homes.

R329.1 General.((The design and construction of swimming pools, spas, and other aquatic recreation facilities shall comply with the 2015 International Swimming Pool and Spa Code, if the facility is one of the following:

1. For the sole use of residents and invited guests at a single-family dwelling;

2. For the sole use of residents and invited guests of a duplex owned by the residents; or

3. Operated exclusively for physical therapy or rehabilitation and under the supervision of a licensed medical practitioner.))This section shall apply to all newly constructed adult family homes and all existing single family homes being converted to adult family homes. This section shall not apply to those adult family homes licensed by the state of Washington department of social and health services prior to July 1, 2001.

R329.2 Reserved.

R329.3 Sleeping room classification. Each sleeping room in an adult family home shall be classified as:

1. Type S - Where the means of egress contains stairs, elevators or platform lifts.

2. Type NS1 - Where one means of egress is at grade level or a ramp constructed in accordance with R325.9 is provided.

3. Type NS2 - Where two means of egress are at grade level or ramps constructed in accordance with R325.9 are provided.

R329.4 Types of locking devices and door activation. All bedroom and bathroom doors shall be openable from the outside when locked.

Every closet shall be readily openable from the inside.

The force required to activate operable parts shall be 5.0 pounds (22.2 N) maximum. Required exit doors shall have no additional locking devices.

Required exit door hardware shall unlock inside and outside mechanisms when exiting the building allowing reentry into the adult family home without the use of a key, tool or special knowledge.

R329.5 Smoke and carbon monoxide alarm requirements. All adult family homes shall be equipped with smoke and carbon monoxide alarms installed as required in Sections R314 and R315.1. Alarms shall be installed in such a manner so that the detection device warning is audible from all areas of the dwelling upon activation of a single alarm.

R329.6 Escape windows and doors. Every sleeping room shall be provided with emergency escape and rescue windows as required by Section R310. No alternatives to the sill height such as steps, raised platforms or other devices placed by the openings will be approved as meeting this requirement.

R329.7 Fire apparatus access roads and water supply for fire protection. Adult family homes shall be served by fire apparatus access roads and water supplies meeting the requirements of the local jurisdiction.

R329.8 Grab bar general requirements. Where facilities are designated for use by adult family home clients, grab bars for water closets, bathtubs and shower stalls shall be installed according to this section.

R329.8.1 Grab bar cross section. Grab bars with a circular cross section shall have an outside diameter of 1 1/4 inch minimum and 2 inches maximum. Grab bars with noncircular cross section shall have a cross section dimension of 2 inches maximum and a perimeter dimension of 4 inches minimum and 4 5/8 inches maximum.

R329.8.2 Grab bar installation. Grab bars shall have a spacing of 1 1/2 inch between the wall and the bar. Projecting objects, control valves and bathtub or shower stall enclosure features above, below and at the ends of the grab bar shall have a clear space of 1 1/2 inch to the grab bar.

EXCEPTION:

Swing-up grab bars shall not be required to meet the 1 1/2 inch spacing requirement.

Fixed position grab bars, when mounted, shall not rotate, spin or move and have a graspable surface finish.

R329.8.3 Grab bars at water closets. Water closets shall have grab bars mounted on both sides. Grab bars can be a combination of fixed position and swing-up bars. Grab bars shall meet the requirements of R325.8. Grab bars shall mount between 33 inches and 36 inches above floor grade. Centerline distance between grab bars, regardless of type used, shall be between 25 inches minimum and 30 inches maximum.

R329.8.3.1 Fixed position grab bars. Fixed position grab bars shall be a minimum of 36 inches in length and start 12 inches from the rear wall.

R329.8.3.2 Swing-up grab bars. Swing-up grab bars shall be a minimum of 28 inches in length from the rear wall.

R329.8.4 Grab bars at bathtubs. Horizontal and vertical grab bars shall meet the requirements of R325.8.

R329.8.4.1 Vertical grab bars. Vertical grab bars shall be a minimum of 18 inches long and installed at the control end wall and head end wall. Grab bars shall mount within 4 inches of the exterior of the bath tub edge or within 4 inches within the bath tub. The bottom end of the bar shall start between 36 inches and 42 inches above floor grade.

EXCEPTION:

The required vertical grab bar can be substituted with a floor to ceiling grab bar meeting the requirements of R325.8 at the control end and head end entry points.

R329.8.4.2 Horizontal grab bars. Horizontal grab bars shall be provided at the control end, head end, and the back wall within the bathtub area. Grab bars shall be mounted between 33 inches and 36 inches above floor grade. Control end and head end grab bars shall be 24 inches minimum in length. Back wall grab bar shall be 36 inches minimum in length.

R329.8.5 Grab bars at shower stalls. Where shower stalls are provided to meet the requirements for bathing facilities, grab bars shall meet the requirements of R325.8.

EXCEPTION:

R329.8.5.1 Vertical grab bars. Vertical grab bars shall be 18 inches minimum in length and installed at the control end wall and head end wall. Vertical bars shall be mounted within 4 inches of the exterior of the shower stall or within 4 inches inside the shower stall. The bottom end of vertical bars mount between 36 inches and 42 inches above floor grade.

R329.8.5.2 Horizontal grab bars. Horizontal grab bars shall be installed on all sides of the shower stall mounted between 33 inches and 36 inches above the floor grade. Horizontal grab bars shall be a maximum of 6 inches from adjacent walls. Horizontal grab bars shall not interfere with shower control valves.

R329.9 Ramps. All interior and exterior ramps, when provided, shall be constructed in accordance with Section R311.8 with a maximum slope of 1 vertical to 12 horizontal. The exception to R311.8.1 is not allowed for adult family homes. Handrails shall be installed in accordance with R325.9.1.

R329.9.1 Handrails for ramps. Handrails shall be installed on both sides of ramps between the slope of 1 vertical to 12 horizontal and 1 vertical and 20 horizontal in accordance with R311.8.3.1 through R311.8.3.3.

R329.10 Stair treads and risers. Stair treads and risers shall be constructed in accordance with R311.7.5. Handrails shall be installed in accordance with R325.10.1.

R329.10.1 Handrails for treads and risers. Handrails shall be installed on both sides of treads and risers numbering from one riser to multiple risers. Handrails shall be installed in accordance with R311.7.8.1 through R311.7.8.4.

R329.11 Shower stalls. Where provided to meet the requirements for bathing facilities, the minimum size of shower stalls for an adult family home shall be 30 inches deep by 48 inches long.

NEW SECTION

WAC 51-51-0330Section R330—Family home child care.

R330 Family home child care. For family home child care with more than six children, each floor level used for family child care purposes shall be served by two remote means of egress. Exterior exit doors shall be operable from the inside without the use of keys or any special knowledge or effort.

Basements located more than 4 feet below grade level shall not be used for family home child care unless one of following conditions exist:

1. Stairways from the basement open directly to the exterior of the building without entering the first floor;

3. One of the two required means of egress is an operable window or door, approved for emergency escape or rescue, that opens directly to a public street, public alley, yard or exit court; or

4. A residential sprinkler system is provided throughout the entire building in accordance with NFPA 13d.

Floors located more than 4 feet above grade level shall not be occupied by children in family home child care.

EXCEPTIONS:	1. Use of toilet facilities while under supervision of an adult staff person;
	2. Family home child care may be allowed on the second story if one of the following conditions exists:
	2.1. Stairways from the second story open directly to the exterior of the building without entering the first floor;
	2.2. One of the two required means of egress discharges directly to the exterior from the second story level, and a self-closing door is installed at the top or bottom of the interior stair leading to the floor below; or
	2.3. A residential sprinkler system is provided throughout the entire building in accordance with NFPA 13d.

Every sleeping or napping room in a family home child care shall have at least one operable window for emergency rescue.

EXCEPTION:

Sleeping or napping rooms having doors leading to two separate means of egress, or a door leading directly to the exterior of the building.

EXCEPTION:

NEW SECTION

WAC 51-51-0331Section R331—Protection against radon.

R331.1 Protection against radon. The radon control provisions of Appendix F of this code shall apply to buildings constructed in high radon potential counties (zone 1) designated in Table AF101(1). The radon control provisions of Appendix F of this code shall also apply to all buildings constructed using the provisions of Section R408.3 Unvented crawl space compliance method.

AMENDATORY SECTION(Amending WSR 19-03-036, filed 1/7/19, effective 7/1/19)

WAC 51-51-0403Section R403—Footings.

R403.1.1 Minimum size. The minimum width, W, and thickness, T, for concrete footings shall be in accordance with Tables R403.1(1) through R403.1(3) and Figure R403.1(1) or R403.1.3, as applicable. The footing width shall be based on the load-bearing value of the soil in accordance with Table R401.4.1. Footing projections, P, shall be not less than 2 inches (51 mm) and shall not exceed the thickness of the footing. Footing thickness and projection for fireplaces shall be in accordance with Section R1001. The size of footings supporting piers and columns shall be based on the tributary load and allowable soil pressure in accordance with Table R401.4.1. Footings for wood foundations shall be in accordance with the details set forth in Section R403.2, and Figures R403.1(2) and R403.1(3).

EXCEPTION:

Light-frame construction shall be permitted to have minimum footing size in accordance with Figures R403.1.1(1) through R403.1.1(4) in lieu of that determined by Table R403.1(1).

Figure R403.1.1(1)

Alternative Minimum Footing Size for Light-Frame Construction a,b,c,d,e,f,g,h,i

20 PSF Snow Load

Notes:	a	The minimum footing size is based on the following assumptions: Material weights per Section R301.2.2.2.1 and soil density = 120 pcf. Wood framed walls = 10 foot; crawlspace stem wall = 6 inches × 36 inches; basement wall = 8 inches × 120 inches. Total load (TL) equal to the maximum of three load combinations: LC1=D+L, LC2=D+S and LC3=D=0.75(L+S), where D=dead load, L=live load, S=snow load. TL=max (LC1, LC2, LC3).
	b	Use tributary span of floor and roof. Figure may be used to size exterior and interior footings.
	c	Add 4 feet to tributary floor span for each wood framed wall above first level (i.e., 4' for 2-story, 8' for 3-story).
	d	Multiply floor span by 1.25 for interior footings supporting continuous joists.
	e	Multiply footing width by (1500 psf/capacity) for soil capacity other than 1500 psf. See Section R403.1.1 for thickness.
	f	Dashed line may be used for interior footing size only.
	g	Use footing size indicated on line above the span combination used.
	h	For span combinations above the upper line, a design professional is required.
	i	Interpolation between footing sizes is allowed. Extrapolation is not allowed.

Figure R403.1.1(2)

Alternative Minimum Footing Size for Light-Frame Construction a,b,c,d,e,f,g,h,i

30 PSF Snow Load

Notes:	a	The minimum footing size is based on the following assumptions: Material weights per Section R301.2.2.2.1 and soil density = 120 pcf. Wood framed walls = 10 foot; crawlspace stem wall = 6 inches × 36 inches; basement wall = 8 inches × 120 inches. Total load (TL) equal to the maximum of three load combinations: LC1=D+L, LC2=D+S and LC3=D=0.75(L+S), where D=dead load, L=live load, S=snow load. TL=max (LC1, LC2, LC3).
	b	Use tributary span of floor and roof. Figure may be used to size exterior and interior footings.
	c	Add 4 feet to tributary floor span for each wood framed wall above first level (i.e., 4' for 2-story, 8' for 3-story).
	d	Multiply floor span by 1.25 for interior footings supporting continuous joists.
	e	Multiply footing width by (1500 psf/capacity) for soil capacity other than 1500 psf. See Section R403.1.1 for thickness.
	f	Dashed line may be used for interior footing size only.
	g	Use footing size indicated on line above the span combination used.
	h	For span combinations above the upper line, a design professional is required.
	i	Interpolation between footing sizes is allowed. Extrapolation is not allowed.

Figure R403.1.1(3)

Alternative Minimum Footing Size for Light-Frame Construction a,b,c,d,e,f,g,h,i

50 PSF Snow Load

Notes:	a	The minimum footing size is based on the following assumptions: Material weights per Section R301.2.2.2.1 and soil density = 120 pcf. Wood framed walls = 10 foot; crawlspace stem wall = 6 inches × 36 inches; basement wall = 8 inches × 120 inches. Total load (TL) equal to the maximum of three load combinations: LC1=D+L, LC2=D+S and LC3=D=0.75(L+S), where D=dead load, L=live load, S=snow load. TL=max (LC1, LC2, LC3).
	b	Use tributary span of floor and roof. Figure may be used to size exterior and interior footings.
	c	Add 4 feet to tributary floor span for each wood framed wall above first level (i.e., 4' for 2-story, 8' for 3-story).
	d	Multiply floor span by 1.25 for interior footings supporting continuous joists.
	e	Multiply footing width by (1500 psf/capacity) for soil capacity other than 1500 psf. See Section R403.1.1 for thickness.
	f	Dashed line may be used for interior footing size only.
	g	Use footing size indicated on line above the span combination used.
	h	For span combinations above the upper line, a design professional is required.
	i	Interpolation between footing sizes is allowed. Extrapolation is not allowed.

Figure R403.1.1(4)

Alternative Minimum Footing Size for Light-Frame Construction a,b,c,d,e,f,g,h,i

70 PSF Snow Load

Notes:	a	The minimum footing size is based on the following assumptions: Material weights per Section R301.2.2.2.1 and soil density = 120 pcf. Wood framed walls = 10 foot; crawlspace stem wall = 6 inches × 36 inches; basement wall = 8 inches × 120 inches. Total load (TL) equal to the maximum of three load combinations: LC1=D+L, LC2=D+S and LC3=D=0.75(L+S), where D=dead load, L=live load, S=snow load. TL=max (LC1, LC2, LC3).
	b	Use tributary span of floor and roof. Figure may be used to size exterior and interior footings.
	c	Add 4 feet to tributary floor span for each wood framed wall above first level (i.e., 4' for 2-story, 8' for 3-story).
	d	Multiply floor span by 1.25 for interior footings supporting continuous joists.
	e	Multiply footing width by (1500 psf/capacity) for soil capacity other than 1500 psf. See Section R403.1.1 for thickness.
	f	Dashed line may be used for interior footing size only.
	g	Use footing size indicated on line above the span combination used.
	h	For span combinations above the upper line, a design professional is required.
	i	Interpolation between footing sizes is allowed. Extrapolation is not allowed.

R403.1.6 Foundation anchorage. Wood sill plates and wood walls supported directly on continuous foundations shall be anchored to the foundation in accordance with this section.

Cold-formed steel framing shall be anchored directly to the foundation or fastened to wood sill plates in accordance with Section R505.3.1 or R603.3.1, as applicable. Wood sill plates supporting cold-formed steel framing shall be anchored to the foundation in accordance with this section.

Wood sole plates at all exterior walls on monolithic slabs, wood sole plates of braced wall panels at building interiors on monolithic slabs and all wood sill plates shall be anchored to the foundation with minimum 1/2-inch-diameter (12.7 mm) anchor bolts spaced not greater than 6 feet (1829 mm) on center or approved anchors or anchor straps spaced as required to provide equivalent anchorage to 1/2-inch-diameter (12.7 mm) anchor bolts. Bolts shall extend not less than 7 inches (178 mm) into concrete or grouted cells of concrete masonry units. The bolts shall be located in the middle third of the width of the plate. A nut and washer shall be tightened on each anchor bolt. There shall be not fewer than two bolts per plate section with one bolt located not more than 12 inches (305 mm) or less than seven bolt diameters from each end of the plate section. Interior bearing wall sole plates on monolithic slab foundation that are not part of a braced wall panel shall be positively anchored with approved fasteners. Sill plates and sole plates shall be protected against decay and termites where required by Sections R317 and R318. Anchor bolts are allowed to be located after the concrete is placed and before it has set as referenced ACI 332.

EXCEPTIONS:	1. Walls 24 inches (610 mm) total length or shorter connecting offset braced wall panels shall be anchored to the foundation with not fewer than one anchor bolt located in the center third of the plate section and shall be attached to adjacent braced wall panels at corners as shown in Item 9 of Table R602.3(1).
	2. Connection of walls 12 inches (305 mm) total length or shorter connecting offset braced wall panels to the foundation without anchor bolts shall be permitted. The wall shall be attached to adjacent braced wall panels at corners as shown in Item 9 of Table R602.3(1).

R404.1.3.3.6 Form materials and form ties. Forms shall be made of wood, steel, aluminum, plastic, a composite of cement and foam insulation, a composite of cement and wood chips, or other approved material suitable for supporting and containing concrete. Forms shall be positioned and secured before placing concrete and shall provide sufficient strength to contain concrete during the concrete placement operation. Form ties shall be steel, solid plastic, foam plastic, a composite of cement and wood chips, a composite of cement and foam plastic, or other suitable material capable of resisting the forces created by fluid pressure of fresh concrete.

AMENDATORY SECTION(Amending WSR 16-03-025, filed 1/11/16, effective 7/1/16)

WAC 51-51-0507Section R507—Decks.

((R507.2.4 Deck lateral load connections. The lateral load connection required by Section R507.1 shall be permitted to be in accordance with Figure R507.2.3(1) or R507.2.3(2). Where the lateral load connection is provided in accordance with Figure R507.2.3(1)))R507.1 Decks. Wood-framed decks shall be in accordance with this section. Decks shall be designed for the live load required in Section R301.5 or the ground snow load indicated in Table R301.2(1), whichever is greater. For decks using materials and conditions not prescribed in this section, refer to Section R301.

TABLE R507.3.1

MINIMUM FOOTING SIZE FOR DECKS

LIVE OR GROUND SNOW LOADb (psf)	TRIBUTARY AREAc (sq.ft.)	SOIL BEARING CAPACITYacd
		1500 psf			2000 psf			≥ 3000 psf
		Side of a square footing (inches)	Diameter of a round footing (inches)	Thicknessf (inches)	Side of a square footing (inches)	Diameter of a round footing (inches)	Thicknessf (inches)	Side of a square footing (inches)	Diameter of a round footing (inches)	Thicknessf (inches)
40	5	7	8	6	7	8	6	7	8	6
	20	10	10	6	9	9	6	7	8	6
	40	14	14	7	12	13	6	10	10	6
	60	17	18	9	15	15	8	12	13	6
	80	20	22	7	17	19	6	14	16	6
	100	22	25	8	19	21	6	15	17	6
	120	24	27	9	21	23	7	17	19	6
	140	26	29	10	22	25	8	18	21	6
	160	28	31	11	24	27	9	20	22	7
50	5	7	8	6	7	8	6	7	8	6
	20	11	12	6	10	10	6	8	8	6
	40	16	16	6	8	14	6	11	12	6
	60	19	21	6	16	18	6	13	15	6
	80	21	24	8	19	21	6	15	17	6
	100	24	27	9	21	23	7	17	19	6
	120	26	30	10	23	26	8	19	21	6
	140	28	32	11	25	28	9	20	23	7
	160	30	34	12	26	30	10	21	24	8
60	5	7	8	6	7	8	6	7	8	6
	20	12	13	6	11	11	6	9	9	6
	40	17	18	6	15	15	8	12	13	6
	60	20	23	7	17	20	6	14	16	6
	80	23	26	9	20	23	7	16	19	6
	100	26	29	10	22	25	8	18	21	6
	120	28	32	11	25	28	9	20	23	7
	140	31	35	12	27	30	10	22	24	8
	160	33	37	13	28	32	11	23	26	9
70	6	7	8	6	7	8	6	7	8	6
	20	13	14	7	11	12	6	9	10	6
	40	18	19	9	16	17	8	13	14	7
	60	21	24	8	19	21	6	15	17	6
	80	25	28	9	21	24	8	18	20	6
	100	28	31	11	24	27	9	20	22	7
	120	30	34	12	26	30	10	21	24	8
	140	33	37	13	28	32	11	23	26	9
	160	35	40	15	30	34	12	25	28	9

For SI: 1 inch = 25.4 mm, 1 square foot = 0.0929 m2, 1 pound per square foot = 0.0479 kPa.
a.	Interpolation permitted, extrapolation not permitted.
b.	Based on highest load case: Dead + Live or Dead + Snow.
c.	Footing dimensions shall allow complete bearing of the post.
d.	If the support is a brick or CMU pier, the footing shall have a minimum 2-inch projection on all sides.
e.	Area, in square feet, of deck surface supported by post and footings.
f.	Minimum thickness shall only apply to plain concrete footings,

R507.4 Deck posts. For single-level decks, wood deck post size shall be in accordance with Table R507.4.

TABLE R507.4

DECK POST HEIGHT

LOADSb (psf)	POST SPECIESc	POST SIZE	TRIBUTARY AREAg,h (square feet)
			20	40	60	80	100	120	140	160
			MAXIMUM DECK POST HEIGHTa (feet-inches)
40 Live Load	Southern Pine	4×4	14-0	13-8	11-0	9-5	8-4	7-5	6-9	6-2
		4×6	14-0	14-0	13-11	12-0	10-8	9-8	8-10	8-2
		6×6	14-0	14-0	11-0	14-0	14-0	14-0	14-0	14-0
		8×8	14-0	14-0	14-0	14-0	14-0	14-0	14-0	14-0
	Douglas Fire, Hem-fire, SPFe	4×4	14-0	13-6	10-10	9-3	8-0	7-0	6-2	5-3
		4×6	14-0	14-0	13-10	11-10	10-6	9-5	8-7	7-10
		6×6	14-0	14-0	14-0	14-0	14-0	14-0	14-0	14-0
		8×8	14-0	14-0	14-0	14-0	14-0	14-0	14-0	14-0
	Redwoodf, Western Cedarsf, Ponderosa Pinef, Red Pinef	4×4	14-0	12-1	9-8	8-22	7-1	6-2	5-3	4-2
		4×6	14-0	14-0	12-4	10-7	9-4	8-4	7-7	6-11
		6×6	14-0	14-0	14-0	14-0	14-0	14-0	14-0	12-10
		8×8	14-0	14-0	14-0	14-0	14-0	14-0	14-0	14-0
50 Ground Snow Load	Southern Pine	4×4	14-0	12-2	9-10	8-5	7-5	9-7	5-11	5-4
		4×6	14-0	14-0	12-6	10-9	9-6	8-7	7-10	7-3
		6×6	14-0	14-0	14-0	14-0	14-0	14-0	14-0	13-4
		8×8	14-0	14-0	14-0	14-0	14-0	14-0	14-0	14-0
	Douglas Fire, Hem-fire, SPFe	4×4	14-0	12-1	9-8	8-2	7-1	6-2	5-3	4-2
		4×6	14-0	14-0	12-4	10-7	9-4	8-4	7-7	6-11
		6×6	14-0	14-0	14-0	14-0	14-0	14-0	14-0	12-10
		8×8	14-0	14-0	14-0	14-0	14-0	14-0	14-0	14-0
	Redwoodf, Western Cedarsf, Ponderosa Pinef, Red Pinef	4×4	14-0	11-8	9-0	6-10	3-7	NP	NP	NP
		4×6	14-0	14-0	12-0	10-0	8-6	7-0	5-3	NP
		6×6	14-0	14-0	14-0	14-0	14-0	14-0	10-8	2-4
		8×8	14-0	14-0	14-0	14-0	14-0	14-0	14-0	14-0
60 Ground Snow Load	Southern Pine	4×4	14-0	11-1	8-11	7-7	6-7	5-10	5-2	4-6
		4×6	14-0	14-0	11-4	9-9	8-7	7-9	7-1	6-6
		6×6	14-0	14-0	14-0	14-0	14-0	14-0	12-9	11-2
		8×8	14-0	14-0	14-0	14-0	14-0	14-0	14-0	14-0
	Douglas Fire, Hem-fire, SPFe	4×4	14-0	10-11	8-8	7-3	6-2	5-0	3-7	NP
		4×6	14-0	13-11	112-	9-7	8-4	7-5	6-8	5-11
		6×6	14-0	14-0	14-0	14-0	14-0	14-0	12-2	10-2
		8×8	14-0	14-0	14-0	14-0	14-0	14-0	14-0	14-0
	Redwoodf, Western Cedarsf, Ponderosa Pinef, Red Pinef	4×4	14-0	10-6	7-9	4-7	NP	NP	NP	NP
		4×6	14-0	13-7	10-9	8-9	7-0	4-9	NP	NP
		6×6	14-0	14-0	14-0	14-0	14-0	9-9	NP	NP
		8×8	14-0	14-0	14-0	14-0	14-0	14-0	14-0	14-0
70 Ground Snow Load	Southern Pine	4×4	14-0	10-2	8-2	6-11	5-11	5-2	4-4	3-4
		4×6	14-0	12-11	10-5	8-11	7-10	7-1	6-5	5-10
		6×6	14-0	14-0	14-0	14-0	14-0	12-9	10-11	8-7
		8×8	14-0	14-0	14-0	14-0	14-0	14-0	14-0	14-0
	Douglas Fire, Hem-fire, SPFe	4×4	14-0	10-1	7-11	6-6	5-3	3-7	NP	NP
		4×6	14-0	12-10	10-3	8-9	7-7	6-8	5-10	4-11
		6×6	14-0	14-0	14-0	14-0	14-0	12-2	9-9	5-9
		8×8	14-0	14-0	14-0	14-0	14-0	14-0	14-0	14-0
	Redwoodf, Western Cedarsf, Ponderosa Pinef, Red Pinef	4×4	14-0	9-5	6-5	NP	NP	NP	NP	NP
		4×6	14-0	12-6	9-8	7-7	5-3	NP	NP	NP
		6×6	14-0	14-0	14-0	14-0	10-8	NP	NP	NP
		8×8	14-0	14-0	14-0	14-0	14-0	14-0	14-0	14-0

For SI: 1 inch = 25.4 mm, 1 square foot = 0.0929 m2, 1 pound per square foot = 0.0479 kPa, NP = Not permitted.
a.	Measured from the underside of the beam to top of footing or pier.
b.	10 psf dead load. Snow load not assumed to be concurrent with live load.
c.	No. 2 grade, wet service factor included.
d.	Notched deck posts shall be sized to accommodate beam size per in accordance with Section R507.5.2.
e.	Includes incising factor.
f.	Incising factor not included.
g.	Area, in square feet, of deck surface supported by post and footing.
h.	Interpolation permitted. Extrapolation not permitted.

R507.5 Deck beams. Maximum allowable spans for wood deck beams, as shown in Figure R507.5, shall be in accordance with Tables R507.5(1) through R507(4). Beam plies shall be fastened with two rows of 10d (3-inch × 0.128-inch) nails minimum at 16 inches (406 mm) on center along each edge. Beams shall be permitted to cantilever at each end up to one-fourth of the allowable beam span. Deck beams of other materials shall be permitted where designed in accordance with accepted engineering practices.

TABLE R507.5(1)

MAXIMUM DECK BEAM SPAN – 40 PSF LIVE LOADc

BEAM SPECIESd	BEAM SIZEe	DECK JOIST SPANa,i (feet)
		6	8	10	12	14	16	18
		MAXIMUM BEAM SPANa,b,f (feet-inches)
Southern Pine	1-2×6	4-7	4-0	3-7	3-3	3-0	2-10	2-7
	1-2×8	5-10	5-1	4-6	4-1	3-10	3-7	3-4
	1-2×10	6-11	6-0	5-4	4-11	4-6	4-3	4-0
	1-2×12	8-2	7-1	6-4	5-9	5-4	5-0	4-8
	2-2×6	6-10	5-11	5-3	4-10	4-6	4-2	3-11
	2-2×8	8-8	7-6	6-9	6-2	5-8	5-4	5-0
	2-2×10	10-4	8-11	8-0	7-3	6-9	6-4	5-11
	2-2×12	12-2	10-6	9-5	8-7	7-11	7-5	7-0
	3-2×6	8-6	7-5	6-8	6-1	5-7	5-3	4-11
	3-2×8	10-11	9-5	8-5	7-8	7-1	6-8	6-3
	3-2×10	12-11	11-2	10-0	9-1	8-5	7-11	7-5
	3-2×12	15-3	13-2	11-9	10-9	9-11	9-4	8-9
Douglas fir-larchg, Spruce-pine-firg	1-2×6	4-1	3-6	3-0	2-6	2-1	1-10	1-7
	1-2×8	5-6	4-9	4-0	3-3	2-9	2-5	2-1
	1-2×10	6-8	5-10	5-1	4-2	3-6	3-1	2-8
	1-2×12	7-9	6-9	6-0	5-1	4-4	3-9	3-3
	2-2×6	6-1	5-3	4-9	4-4	4-0	3-8	3-3
	2-2×8	8-2	7-1	6-4	5-9	5-4	4-10	4-3
	2-2×10	10-0	8-7	7-9	7-0	6-6	6-1	5-5
	2-2×12	11-7	10-0	8-11	8-2	7-7	7-1	6-7
	3-2×6	7-8	6-7	5-11	5-5	5-0	4-8	4-5
	3-2×8	10-3	8-3	7-11	7-3	6-8	6-3	5-11
	3-2×10	12-6	10-10	9-8	8-10	8-2	7-8	7-2
	3-2×12	14-6	12-7	11-3	10-3	9-6	8-11	8-5
Redwoodh, Western Cedarsh, Ponderosa Pineh, Red Pineh	1-2×6	4-2	3-7	3-1	2-7	2-2	1-10	1-8
	1-2×8	5-4	4-7	4-1	3-4	2-10	2-6	2-2
	1-2×10	6-6	5-7	5-0	4-3	3-8	3-2	2-9
	1-2×12	7-6	6-6	5-10	5-3	4-5	3-10	3-5
	2-2×6	6-2	5-4	4-10	4-5	4-1	3-9	3-4
	2-2×8	7-10	6-10	6-1	5-7	5-2	4-10	4-4
	2-2×10	9-7	8-4	7-5	6-9	6-3	5-10	5-6
	2-2×12	11-1	9-8	8-7	7-10	7-3	6-10	6-5
	3-2×6	7-8	6-9	6-0	5-6	5-1	4-9	4-6
	3-2×8	9-10	8-6	7-7	6-11	6-5	6-0	5-8
	3-2×10	12-0	10-5	9-4	8-6	7-10	7-4	6-11
	3-2×12	13-11	12-1	10-9	9-10	9-1	8-6	8-1

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa, 1 pound = 0.454 kg.
a.	Interpolation permitted. Extrapolation not permitted.
b.	Beams supporting a single span of joists with or without cantilever.
c.	Dead load = 10 psf, L/Δ = 360 at main span, L/Δ = 180 at cantilever. Snow load not assumed to be concurrent with live load.
d.	No. 2 grade, wet service factor included.
e.	Beam depth shall be equal to or greater than the depth intersecting joist for a flush beam connection.
f.	Beam cantilevers are limited to the adjacent beam's span divided by 4.
g.	Includes incising factor.
h.	Incising factor not included.
i.	Deck joist span as shown in Figure R507.5.

TABLE R507.5(2)

MAXIMUM DECK BEAM SPAN – 50 PSF LIVE LOADc

BEAM SPECIESd	BEAM SIZEe	DECK JOIST SPANa,i (feet)
		6	8	10	12	14	16	18
		MAXIMUM BEAM SPANa,b,f (feet-inches)
Southern Pine	1-2×6	4-2	3-8	3-3	2-11	2-9	2-5	2-2
	1-2×8	5-4	4-7	4-1	3-9	3-6	3-3	2-10
	1-2×10	6-4	5-6	4-11	4-6	4-2	3-10	3-8
	1-2×12	7-6	6-5	5-9	5-3	4-10	4-7	4-3
	2-2×6	6-3	5-5	4-10	4-5	4-1	3-10	3-7
	2-2×8	7-11	6-10	6-2	5-7	5-2	4-10	4-7
	2-2×10	9-5	8-2	7-3	6-8	6-2	5-9	5-5
	2-2×12	11-1	9-7	8-7	7-10	7-3	6-9	6-5
	3-2×6	7-10	6-9	6-1	5-6	5-1	4-9	4-6
	3-2×8	9-11	8-7	7-8	7-0	6-6	6-16	5-9
	3-2×10	11-9	10-2	9-1	8-4	7-8	7-2	6-9
	3-2×12	13-11	12-0	10-9	9-10	9-1	8-6	8-0
Douglas fir-larchg, Spruce-pine-firg	1-2×6	3-9	3-3	2-6	2-1	1-9	1-6	1-4
	1-2×8	5-0	4-3	3-4	2-9	2-3	2-0	1-9
	1-2×10	6-1	5-4	4-3	3-6	2-11	2-6	2-3
	1-2×12	7-1	6-2	5-2	4-3	3-7	3-1	2-9
	2-2×6	5-7	4-10	4-4	3-11	3-6	3-0	2-8
	2-2×8	7-5	6-5	5-9	5-3	4-7	4-0	3-6
	2-2×10	9-1	7-10	7-0	6-5	5-11	5-1	4-6
	2-2×12	10-7	9-2	8-2	7-5	6-11	6-3	5-6
	3-2×6	7-0	6-0	5-5	4-11	4-7	4-3	4-0
	3-2×8	9-4	8-1	7-3	6-7	6-1	5-8	5-4
	3-2×10	11-5	9-10	8-10	8-1	7-5	7-0	6-7
	3-2×12	13-3	11-6	10-3	9-5	8-8	8-1	7-8
Redwoodh, Western Cedarsh, Ponderosa Pineh, Red Pineh	1-2×6	3-10	3-4	2-7	2-2	1-10	1-7	1-5
	1-2×8	4-10	4-2	3-5	2-10	2-4	2-1	1-10
	1-2×10	5-11	5-1	4-4	3-7	3-0	2-8	2-4
	1-2×12	6-10	5-11	5-4	4-4	3-8	3-2	2-10
	2-2×6	5-8	4-11	4-5	4-0	3-7	3-1	2-9
	2-2×8	7-2	6-3	5-7	5-1	4-8	4-1	3-8
	2-2×10	8-9	7-7	6-9	6-2	5-9	5-3	4-8
	2-2×12	10-2	8-10	7-10	7-2	6-8	6-3	5-8
	3-2×6	7-1	6-2	5-6	5-0	4-8	4-4	4-1
	3-2×8	9-0	7-9	6-11	6-4	5-11	5-6	5-2
	3-2×10	11-0	9-6	8-6	7-9	7-2	6-9	6-4
	3-2×12	12-9	11-0	9-10	9-0	8-4	7-9	7-4

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa, 1 pound = 0.454 kg.
a.	Interpolation permitted. Extrapolation not permitted.
b.	Beams supporting a single span of joists with or without cantilever.
c.	Dead load = 10 psf, L/Δ = 360 at main span, L/Δ = 180 at cantilever. Snow load not assumed to be concurrent with live load.
d.	No. 2 grade, wet service factor included.
e.	Beam depth shall be equal to or greater than the depth intersecting joist for a flush beam connection.
f.	Beam cantilevers are limited to the adjacent beam's span divided by 4.
g.	Includes incising factor.
h.	Incising factor not included.
i.	Deck joist span as shown in Figure R507.5.

TABLE R507.5(3)

MAXIMUM DECK BEAM SPAN – 60 PSF LIVE LOADc

BEAM SPECIESd	BEAM SIZEe	DECK JOIST SPANa,i (feet)
		6	8	10	12	14	16	18
		MAXIMUM BEAM SPANa,b,f (feet-inches)
Southern Pine	1-2×6	3-11	3-4	3-0	2-9	2-5	2-1	1-10
	1-2×8	4-11	4-3	3-10	3-6	3-2	2-9	2-5
	1-2×10	5-10	5-1	4-6	4-2	3-10	3-6	3-1
	1-2×12	6-11	6-0	5-4	4-10	4-6	4-3	3-10
	2-2×6	5-9	5-0	4-6	4-1	3-9	3-6	3-4
	2-2×8	7-4	6-4	5-8	5-2	4-9	4-6	4-3
	2-2×10	8-8	7-6	6-9	6-2	5-8	5-4	5-0
	2-2×12	10-3	8-11	7-11	7-3	6-8	6-3	5-11
	3-2×6	7-3	6-3	5-7	5-1	4-9	4-5	4-2
	3-2×8	9-2	7-11	7-1	6-6	6-0	5-7	5-3
	3-2×10	10-11	9-5	8-5	7-8	7-2	6-8	6-3
	3-2×12	12-10	11-2	9-11	9-1	8-5	7-10	7-5
Douglas fir-larchg, Spruce-pine-firg	1-2×6	3-5	2-9	2-2	1-9	1-6	1-3	1-1
	1-2×8	4-8	3-8	2-10	2-4	1-11	1-8	1-6
	1-2×10	5-8	4-8	3-8	3-0	2-6	2-2	1-11
	1-2×12	6-7	5-8	4-5	3-7	3-1	2-7	2-3
	2-2×6	5-2	4-5	4-0	3-6	3-0	1-11	1-8
	2-2×8	6-11	5-11	5-4	4-8	3-11	3-5	3-0
	2-2×10	8-5	7-3	6-6	5-11	5-1	4-5	3-10
	2-2×12	9-9	8-5	7-7	6-11	6-2	5-4	4-8
	3-2×6	6-5	5-7	5-0	4-7	4-3	3-11	3-5
	3-2×8	8-8	7-6	6-8	6-1	5-8	5-2	4-7
	3-2×10	10-7	9-2	8-2	7-5	6-11	6-5	5-10
	3-2×12	12-3	10-8	9-6	8-8	8-0	7-6	7-1
Redwoodh, Western Cedarsh, Ponderosa Pineh, Red Pineh	1-2×6	3-6	2-10	2-3	1-10	1-7	1-4	1-2
	1-2×8	4-6	3-9	2-11	2-5	2-0	1-9	1-7
	1-2×10	5-6	4-9	3-9	3-1	2-7	2-3	2-0
	1-2×12	6-4	5-6	4-7	3-9	3-2	2-9	2-5
	2-2×6	5-3	4-6	4-1	3-8	3-1	2-8	2-4
	2-2×8	6-8	5-9	5-2	4-8	4-1	3-6	3-1
	2-2×10	8-1	7-0	6-3	5-9	5-2	4-6	4-0
	2-2×12	9-5	8-2	7-3	6-8	6-2	5-6	4-10
	3-2×6	6-7	5-8	5-1	4-8	4-4	4-0	3-7
	3-2×8	8-4	7-2	6-5	5-11	5-5	5-1	4-8
	3-2×10	10-2	8-10	7-10	7-2	6-8	6-3	5-10
	3-2×12	11-9	10-2	9-1	8-4	7-8	7-3	6-10

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa, 1 pound = 0.454 kg.
a.	Interpolation permitted. Extrapolation not permitted.
b.	Beams supporting a single span of joists with or without cantilever.
c.	Dead load = 10 psf, L/Δ = 360 at main span, L/Δ = 180 at cantilever. Snow load not assumed to be concurrent with live load.
d.	No. 2 grade, wet service factor included.
e.	Beam depth shall be equal to or greater than the depth intersecting joist for a flush beam connection.
f.	Beam cantilevers are limited to the adjacent beam's span divided by 4.
g.	Includes incising factor.
h.	Incising factor not included.
i.	Deck joist span as shown in Figure R507.5.

TABLE R507.5(4)

MAXIMUM DECK BEAM SPAN – 70 PSF LIVE LOADc

BEAM SPECIESd	BEAM SIZEe	DECK JOIST SPANa,i (feet)
		6	8	10	12	14	16	18
		MAXIMUM BEAM SPANa,b,f (feet-inches)
Southern Pine	1-2×6	3-8	3-2	2-10	2-1	1-10	1-4	1-7
	1-2×8	4-7	4-0	3-7	3-3	2-9	2-5	2-2
	1-2×10	5-6	4-9	4-3	3-10	3-7	3-1	2-9
	1-2×12	6-5	5-7	5-0	4-7	4-3	3-9	3-4
	2-2×6	5-5	4-8	4-2	3-10	3-6	3-3	3-1
	2-2×8	6-10	5-11	5-4	4-10	4-6	4-2	3-11
	2-2×10	8-2	7-1	6-4	5-9	5-4	5-0	4-8
	2-2×12	9-7	8-4	7-5	6-9	6-3	5-10	5-6
	3-2×6	6-9	5-10	5-3	4-9	4-5	4-2	3-11
	3-2×8	8-7	7-5	6-8	6-1	5-7	5-3	4-11
	3-2×10	10-2	8-10	7-11	7-2	6-8	6-3	5-10
	3-2×12	12-0	10-5	9-4	8-6	7-10	7-41	6-11
Douglas fir-larchg, Spruce-pine-firg	1-2×6	3-3	2-5	1-10	1-6	1-3	1-1	1-0
	1-2×8	4-4	3-2	2-6	2-0	1-8	1-6	1-4
	1-2×10	5-4	4-1	3-2	2-7	2-2	1-11	1-8
	1-2×12	6-2	5-0	3-10	3-2	2-8	2-4	2-0
	2-2×6	4-10	4-2	3-9	3-1	2-7	2-3	2-0
	2-2×8	6-5	5-7	5-0	4-1	3-5	3-0	2-8
	2-2×10	7-10	6-10	6-1	5-39	4-5	3-10	3-5
	2-2×12	9-2	7-11	7-1	6-4	5-5	4-8	4-1
	3-2×6	6-0	5-31	4-8	4-3	3-11	3-5	3-0
	3-2×8	8-1	7-0	6-3	5-8	5-2	4-6	4-0
	3-2×10	9-10	8-6	7-8	7-0	6-5	5-9	5-1
	3-2×12	11-6	9-11	8-11	8-1	7-6	7-0	6-3
Redwoodh, Western Cedarsh, Ponderosa Pineh, Red Pineh	1-2×6	3-4	2-6	1-11	1-7	1-4	1-2	1-0
	1-2×8	4-2	3-3	2-7	2-1	1-9	1-7	1-4
	1-2×10	5-1	4-2	3-3	2-8	2-3	2-0	1-9
	1-2×12	5-11	5-1	4-0	3-3	2-9	2-5	2-1
	2-2×6	4-11	4-3	3-10	3-2	2-8	2-4	2-1
	2-2×8	6-3	5-5	4-10	4-2	3-7	3-1	2-9
	2-2×10	7-7	6-7	5-10	5-4	4-7	3-11	3-6
	2-2×12	8-10	7-7	6-10	6-3	5-6	4-10	4-3
	3-2×6	6-2	5-4	4-9	4-4	4-0	3-6	3-1
	3-2×8	7-9	6-9	6-0	5-6	5-1	4-8	4-1
	3-2×10	9-6	8-3	7-4	6-9	6-3	5-10	5-3
	3-2×12	11-0	9-6	8-6	7-9	7-3	6-9	6-4

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa, 1 pound = 0.454 kg.
a.	Interpolation permitted. Extrapolation not permitted.
b.	Beams supporting a single span of joists with or without cantilever.
c.	Dead load = 10 psf, L/Δ = 360 at main span, L/Δ = 180 at cantilever. Snow load not assumed to be concurrent with live load.
d.	No. 2 grade, wet service factor included.
e.	Beam depth shall be equal to or greater than the depth intersecting joist for a flush beam connection.
f.	Beam cantilevers are limited to the adjacent beam's span divided by 4.
g.	Includes incising factor.
h.	Incising factor not included.
i.	Deck joist span as shown in Figure R507.5.

R507.6 Deck joists. Maximum allowable spans for wood deck joists, as shown in Figure R507.6, shall be in accordance with Table R507.6. The maximum joist spacing shall be limited by the decking materials in accordance with Table R507.7.

TABLE R507.6

MAXIMUM DECK JOIST SPANS

LOADa (psf)	JOIST SPECIESb	JOIST SIZE	JOIST SPACING (inches)			ADJACENT JOIST SPANg (feet)
			12	16	24	4	6	8	10	12	14	16	18
			MAXIMUM JOIST SPANc			MAXIMUM CANTILEVERd (feet-inches)
40 Live Load	Southern Pine	2×6	9-11	9-0	7-7	1-0	1-6	1-5	NP	NP	NP	NP	NP
		2×8	13-1	11-10	9-8	1-0	1-6	2-0	2-6	2-3	NP	NP	NP
		2×10	16-2	14-0	11-5	1-0	1-6	2-0	2-6	3-0	3-4	3-4	NP
		2×12	18-0	16-6	13-6	1-0	1-6	2-0	-6	3-0	3-6	4-0	4-1
	Douglas Fire, Hem-fire, SPFe	2×6	9-6	8-4	6-10	1-0	1-6	1-4	NP	NP	NP	NP	NP
		2×8	12-6	11-1	9-1	1-0	1-6	2-0	2-3	2-0	NP	NP	NP
		2×10	15-8	13-7	11-1	1-0	1-6	2-0	2-6	3-0	3-3	NP	NP
		2×12	18-0	15-9	12-10	1-0	1-6	2-0	2-6	3-0	3-6	3-11	3-11
	Redwoodf, Western Cedarsf, Ponderosa Pinef, Red Pinef	2×6	8-10	8-0	6-10	1-0	1-4	1-1	NP	NP	NP	NP	NP
		2×8	11-8	10-7	8-8	1-0	1-6	2-0	1-11	NP	NP	NP	NP
		2×10	14-11	13-0	10-7	1-0	1-6	2-0	2-6	3-0	2-9	NP	NP
		2×12	17-5	15-1	12-4	1-0	1-6	2-0	2-6	3-0	3-6	3-8	NP
50 Ground Snow Load	Southern Pine	2×6	9-2	8-4	7-4	1-0	1-6	1-5	NP	NP	NP	NP	NP
		2×8	12-1	11-0	9-7	1-0	1-6	2-0	2-5	2-3	NP	NP	NP
		2×10	15-5	14-1	12-3	1-0	1-6	2-0	2-6	3-0	3-1	NP	NP
		2×12	18-0	17-1	14-6	1-0	1-6	2-0	2-6	3-0	3-6	3-10	3-10
	Douglas Fire, Hem-fire, SPFe	2×6	8-10	8-0	7-0	1-0	1-6	1-4	NP	NP	NP	NP	NP
		2×8	11-7	10-7	9-3	1-0	1-6	2-0	2-3	NP	NP	NP	NP
		2×10	14-10	13-6	11-9	1-0	1-6	2-0	2-6	3-0	3-0	NP	NP
		2×12	18-0	16-5	13-9	1-0	1-6	2-0	2-6	3-0	3-6	3-8	NP
	Redwoodf, Western Cedarsf, Ponderosa Pinef, Red Pinef	2×6	8-3	7-6	6-8	1-0	1-4	1-1	NP	NP	NP	NP	NP
		2×8	10-10	9-10	8-7	1-0	1-6	2-0	1-11	NP	NP	NP	NP
		2×10	13-10	12-7	11-0	1-0	1-6	2-0	2-6	2-9	NP	NP	NP
		2×12	16-10	15-3	13-2	1-0	1-6	2-0	2-6	3-0	3-5	3-5	NP
60 Ground Snow Load	Southern Pine	2×6	8-8	7-10	6-10	1-0	1-6	1-5	NP	NP	NP	NP	NP
		2×8	11-5	10-4	9-1	1-0	1-6	2-0	2-4	NP	NP	NP	NP
		2×10	14-7	13-3	11-7	1-0	1-6	2-0	2-6	2-11	2-11	NP	NP
		2×12	17-8	16-1	14-0	1-0	1-6	2-0	2-6	3-0	3-6	3-7	NP
	Douglas Fire, Hem-fire, SPFe	2×6	8-4	7-6	6-7	1-0	1-6	1-4	NP	NP	NP	NP	NP
		2×8	10-11	9-11	8-8	1-0	1-6	2-0	2-2	NP	NP	NP	NP
		2×10	13-11	12-8	11-1	1-0	1-6	2-0	2-6	2-10	NP	NP	NP
		2×12	17-0	15-5	13-6	1-0	1-6	2-0	2-6	3-0	3-5	3-5	NP
	Redwoodf, Western Cedarsf, Ponderosa Pinef, Red Pinef	2×6	7-9	7-0	6-2	1-0	1-4	NP	NP	NP	NP	NP	NP
		2×8	10-2	9-3	8-1	1-0	1-6	2-0	1-11	NP	NP	NP	NP
		2×10	13-0	11-10	10-4	1-0	1-6	2-0	2-6	2-7	NP	NP	NP
		2×12	15-10	14-4	12-7	1-0	1-6	2-0	2-6	3-0	3-2	NP	NP
70 Ground Snow Load	Southern Pine	2×6	8-3	7-6	6-6	1-0	1-6	1-5	NP	NP	NP	NP	NP
		2×8	10-10	9-10	8-7	1-0	1-6	2-0	2-2	NP	NP	NP	NP
		2×10	13-10	12-7	11-0	1-0	1-6	2-0	2-6	2-9	NP	NP	NP
		2×12	16-10	15-3	13-4	1-0	1-6	2-0	2-6	3-0	3-5	3-5	NP
	Douglas Fire, Hem-fire, SPFe	2×6	7-11	7-2	6-3	1-0	1-6	NP	NP	NP	NP	NP	NP
		2×8	10-5	9-5	8-3	1-0	1-6	2-0	2-1	NP	NP	NP	NP
		2×10	13-3	-12-0	10-6	1-0	1-6	2-0	2-6	2-8	NP	NP	NP
		2×12	16-1	14-8	12-10	1-0	1-6	2-0	2-6	3-0	3-3	3-3	NP
	Redwoodf, Western Cedarsf, Ponderosa Pinef, Red Pinef	2×6	7-4	6-8	5-10	1-0	1-4	NP	NP	NP	NP	NP	NP
		2×8	9-8	8-10	7-8	1-0	1-6	1-11	NP	NP	NP	NP	NP
		2×10	12-4	11-3	9-10	1-0	1-6	2-0	2-6	2-6	NP	NP	NP
		2×12	15-0	13-8	11-11	1-0	1-6	2-0	2-6	2-0	3-0	NP	NP

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa, 1 pound = 0.454 kg, NP = Not permitted.
a.	Dead load = 10 psf dead load. Snow load not assumed to be concurrent with live load.
b.	No. 2 grade, wet service factor included.
c.	L/Δ = 360 at main span.
d.	L/Δ = 180 at cantilever with 220-pound point load applied to end.
e.	Includes incising factor.
f.	Incising factor not included.
g.	Interpolation permitted. Extrapolation not permitted.

R507.9.1.2 Band joist details. Band joists supporting a ledger shall be a minimum 2-inch-nominal (51 mm), solid-sawn, spruce-pine-fir or better lumber or minimum 1-inch (25 mm) nominal engineered wood rim boards in accordance with Section R502.1.7. Band joists shall bear fully on the primary structure capable of supporting all required loads.

R507.9.2 Deck lateral load connections. Lateral loads shall be transferred to the ground or to a structure capable of transmitting them to the ground. Where the lateral load connection is provided in accordance with Figure R507.9.2(1), hold-down tension devices shall be installed in not less than two locations per deck, within 24 inches of each end of the deck. Each device shall have an allowable stress design capacity of not less than 1500 pounds (6672 N). Where the lateral load connections are provided in accordance with Figure ((R507.2.3))R507.9.2(2), the hold-down tension devices shall be installed in not less than four locations per deck, and each device shall have an allowable stress design capacity of not less than 750 pounds (3336 N).

EXCEPTION:

Decks not more than 30 inches above grade at any point may be unattached.

TABLE ((R507.2.1))R507.9.1

PLACEMENT OF LAG SCREWS AND BOLTS IN DECK LEDGERS AND BAND JOISTS

MINIMUM END AND EDGE DISTANCES AND SPACING BETWEEN ROWS
	TOP EDGE	BOTTOM EDGE	ENDS	ROW SPACING
Ledgera	2 inchesd	3/4 inch	2 inchesb	1 5/8 inchesb
Band joistc	3/4 inch	2 inchese	2 inchesb	1 5/8 inchesb

For SI:	1 inch = 25.4 mm.
a	Lag screws or bolts shall be staggered from the top to the bottom along the horizontal run of the deck ledger in accordance with Figure R507.2.1(1).
b	Maximum 5 inches.
c	For engineered rim joists, the manufacturer's recommendations shall govern.
d	The minimum distance from bottom row of lag screws to the top edge of the ledger shall be in accordance with Figure R507.2.1(1).
e	The 2 inches may be reduced to 3/4 inch when the band joist is directly supported by a mudsill, a header or by double top wall plates.

TABLE R507.9.3(1)

DECK LEGER CONNECTION TO BAND JOIST

LOADc (psf)	JOIST SPANa (feet)	1/2-inch diameter leg screw with 1/2-inch maximum sheathingd,e	1/2-inch diameter bolt with 1/2-inch maximum sheathinge	1/2-inch diameter bolt with 1-inch maximum sheathingf
LOADc (psf)	JOIST SPANa (feet)	ON-CENTER SPACING OF FASTENERSb (inches)
40 Live Load	6	30	36	36
	8	23	36	36
	10	18	34	29
	12	15	29	24
	14	13	24	21
	16	11	21	18
	18	10	19	16
50 Ground Snow Load	6	29	36	36
	8	22	36	35
	10	17	33	28
	12	14	27	23
	14	12	23	20
	16	11	20	17
	18	9	18	15
60 Ground Snow Load	6	25	36	36
	8	18	35	30
	10	17	33	28
	12	14	27	23
	14	12	23	20
	16	11	20	17
	18	9	18	15
70 Ground Snow Load	6	22	36	35
	8	16	31	26
	10	13	25	21
	12	11	20	17
	14	9	17	15
	16	8	15	13
	18	7	13	11

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
a.	Interpolation permitted. Extrapolation not permitted.
b.	Legers shall be flashed in accordance with Section R703.4 to prevent water from contacting the house band joist.
c.	Dead Load = 10 psf. Snow load shall not be assumed to act concurrently with live load.
d.	The tip of the lag screw shall fully extend beyond the inside face of the band joist.
e.	Sheathing shall be wood structural panel or solid sawn lumber.
f.	Sheathing shall be permitted to be wood structural panel, gypsum board, fiberboard, lumber or foam sheathing. Up to 1/2 inch thickness of stacked washers shall be permitted to substitute for up to 1/2 inch of allowable sheathing thickness where combined with wood structural panel or lumber sheathing.

Reviser's note: RCW 34.05.395 requires the use of underlining and deletion marks to indicate amendments to existing rules. The rule published above varies from its predecessor in certain respects not indicated by the use of these markings.

AMENDATORY SECTION(Amending WSR 16-03-025, filed 1/11/16, effective 7/1/16)

WAC 51-51-0602Section R602—Wood wall framing.

((R602.7.5 Supports for headers. This section is not adopted.))R602.1.1 Sawn lumber. Sawn lumber shall be identified by a grade mark of an accredited lumber grading or inspection agency and have design values certified by an accreditation body that complies with DOC PS 20. In lieu of a grade mark, a certification of inspection issued by a lumber grading or inspection agency meeting the requirements of this section shall be accepted.

R602.1.1.1 Used sawn lumber. Used sawn lumber in good condition and devoid of areas of decay shall meet the requirements of Section 602.1.1 or shall comply with the following:

1. Dimensional lumber that has a nominal thickness of 2 inches with a nominal width of 6 inches, or less, shall be assumed to be spruce-pine-fir stud grade and shall have structural properties assigned in accordance with current adopted standards. All other dimensional lumber shall be assumed to be hem-fir No. 2 grade and shall have structural properties assigned in accordance with current adopted standards.

R602.9 ((Foundation))Cripple walls. Foundation cripple walls shall be framed of studs not smaller than the studding above. When exceeding 4 feet (1219 mm) in height, such walls shall be framed of studs having the size required for an additional story.

Cripple walls supporting bearing walls or exterior walls or interior braced wall panels as required in Sections R403.1.2 and R602.10.9.1 with a stud height less than 14 inches (356 mm) shall be continuously sheathed on one side with wood structural panels fastened to both the top and bottom plates in accordance with Table R602.3(1), or the cripple walls shall be constructed of solid blocking. All cripple walls shall be supported on continuous footings or foundations.

EXCEPTION:

Footings supporting cripple walls used to support interior braced wall panels as required in Sections R403.1.2 and R602.10.9.1 shall be continuous for the required length of the cripple wall and constructed beyond the cripple wall for a minimum distance of 4 inches and a maximum distance of the footing thickness. The footings extension is not required at intersections with other footings.

((R602.10.11))R602.10.10 Cripple wall bracing. Cripple walls shall be constructed in accordance with Section R602.9 and braced in accordance with this section. Cripple walls supporting bearing walls or exterior walls or interior braced wall panels as required in Section R403.1.2 shall be braced with the length and method of bracing used for the wall above in accordance with Tables R602.10.3(1) and R602.10.3(3), and the applicable adjustment factors in Table R602.10.3(2) or R602.10.3(4), respectively, except the length of the cripple wall bracing shall be multiplied by a factor of 1.15.

Where gypsum wall board is not used on the inside of the cripple wall bracing, the length adjustments for the elimination of the gypsum wallboard, or equivalent, shall be applied as directed in Tables R602.10.3(2) and R602.10.3(4) to the length of cripple wall bracing required. This adjustment shall be taken in addition to the 1.15 increase.

NEW SECTION

WAC 51-51-0608Section 608—Exterior concrete wall construction.

R608.1 General. Exterior concrete walls shall be designed and constructed in accordance with the provisions of this section or in accordance with the provisions of PCA 100, ACI 318, or ACI 332. Where PCA 100, ACI 318, or ACI 332, or the provisions of this section are used to design concrete walls, project drawings, typical details and specifications are not required to bear the seal of the architect or engineer responsible for design, unless otherwise required by the state law of the jurisdiction having authority.

R608.5.1 Concrete and materials for concrete. Materials used in concrete, and the concrete itself, shall conform to requirements of this section, PCA 100, ACI 318, or ACI 332.

AMENDATORY SECTION(Amending WSR 16-03-025, filed 1/11/16, effective 7/1/16)

WAC 51-51-0703Section R703—Exterior covering.

R703.1 General. Exterior walls shall provide the building with a weather-resistant exterior wall envelope. The exterior wall envelope shall include flashing as described in Section R703.4.

EXCEPTION:

Log walls designed and constructed in accordance with the provisions of ICC 400.

R703.1.1 Water resistance. The exterior wall envelope shall be designed and constructed in a manner that prevents the accumulation of water within the wall assembly by providing a water-resistant barrier behind the exterior veneer as required by Section R703.2 and a means of draining water that enters the assembly to the exterior. Protection against condensation in the exterior wall assembly shall be provided in accordance with Section R702.7 of this code.

EXCEPTIONS:	1. A weather-resistant exterior wall envelope shall not be required over concrete or masonry walls designed in accordance with Chapter 6 and flashed according to Section R703.4 or R703.8.
	2. Compliance with the requirements for a means of drainage, and the requirements of Sections R703.2 and R703.4, shall not be required for an exterior wall envelope that has been demonstrated to resist wind-driven rain through testing of the exterior wall envelope, including joints, penetrations and intersections with dissimilar materials, in accordance with ASTM E 331 under the following conditions:
	2.1. Exterior wall envelope test assemblies shall include at least one opening, one control joint, one wall/eave interface and one wall sill. All tested openings and penetrations shall be representative of the intended end-use configuration.
	2.2. Exterior wall envelope test assemblies shall be at least 4 feet (1219 mm) by 8 feet (2438 mm) in size.
	2.3. Exterior wall assemblies shall be tested at a minimum differential pressure of 6.24 pounds per square foot (299Pa).
	2.4. Exterior wall envelope assemblies shall be subjected to a minimum test exposure duration of 2 hours.
	The exterior wall envelope design shall be considered to resist wind-driven rain where the results of testing indicate that water did not penetrate control joints in the exterior wall envelope; joints at the perimeter of opening penetration; or intersections of terminations with dissimilar materials.
	3. The requirement for a means of drainage shall not be construed to mean an air space cavity under the exterior cladding for an exterior wall clad with panel or lapped siding made of plywood, engineered wood, hardboard, or fiber cement. A water-resistive barrier as required by Section R703.2 will be required on exterior walls.

R703.2 Water-resistive barrier. Not fewer than one layer of water-resistive barrier shall be applied over studs or sheathing with flashing as indicated in Section R703.4, in such a manner as to provide a continuous water resistive barrier behind the exterior wall veneer. Water-resistive barrier materials shall comply with one of the following:

1. No. 15 felt complying with ASTM D226, Type 1.

2. ASTM E2556, Type 1 or 2.

3. ASTM E331 in accordance with Section R703.1.1; or

4. Other approved materials in accordance with the manufacturer's installation instructions.

R703.4 Flashing. Approved corrosion-resistant flashing shall be applied shingle-fashion in a manner to prevent entry of water into the wall cavity or penetration of water to the building structure framing components. Self-adhered membranes used as flashing shall comply with AAMA 711. Fluid-applied membranes used as flashing in exterior walls shall comply with AAMA 714. The flashing shall extend to the surface of the exterior wall finish. Approved corrosion-resistant flashing shall be installed at all of the following locations:

1. Exterior window and door openings. Flashing at exterior window and door openings shall extend to the surface of the exterior wall finish or to the water resistive barrier complying with Section 703.2 for subsequent drainage. Mechanically attached flexible flashings shall comply with AAMA 712.

2. At the intersection of chimneys or other masonry construction with frame or stucco walls, with projecting lips on both sides under stucco copings.

3. Under and at the ends of masonry, wood or metal copings and sills.

4. Continuously above all projecting wood trim.

5. Where exterior porches, decks or stairs attach to a wall or floor assembly of wood-frame construction.

6. At wall and roof intersections.

7. At built-in gutters.

R703.10.2 Lap siding. Fiber-cement lap siding having a maximum width of 12 inches (305 mm) shall comply with the requirements of ASTM C 1186, Type A, minimum Grade II or ISO 8336, Category A, minimum Class 2. Lap siding shall be lapped a minimum of 1 1/4 inches (32 mm) and lap siding shall be installed in accordance with the manufacturer's installation instructions or shall be designed to comply with Section R703.1. Lap siding courses shall be installed with the fastener heads exposed or concealed, in accordance with Table R703.3(1) or approved manufacturer's instructions.

AMENDATORY SECTION(Amending WSR 13-04-068, filed 2/1/13, effective 7/1/13)

WAC 51-51-1006Section R1006—Exterior air supply.

((R1006.2))R1006.4 Passageway. This section is not adopted.

R1006.6 Solid fuel burning appliances and fireplaces. Solid fuel burning appliances and fireplaces shall be provided with tight fitting metal or ceramic glass doors, and:

1. A source from outside the structure of primary combustion air, connected to the appliance as per manufacturer's specification. The air inlet shall originate at a point below the fire box. The duct shall be 4 inches or greater in diameter, not exceed 20 feet in length, and be installed as per manufacturer's instructions; or

2. The appliance and manufacturer's recommended combustion air supply, as an installed unit, shall be certified by an independent testing laboratory to have passed Test No. 11-Negative Pressure Test, Section 12.3, of ULC S627-M1984 "Space Heaters for Use with Solid Fuels," modified as follows:

Negative pressure of 8 Pascal shall be initially established with the chamber sealed and the air supply, if not directly connected to the appliance, closed off.

The air supply if not directly connected to the appliance, shall then be opened.

The maximum allowable air exchange rate from chamber leakage and intentional air supply for the unit (appliance with combustion air supply) in the test chamber is 3.5 air changes per hour, or 28 cfm (cubic feet of air per minute), whichever is less.

EXCEPTION:	Combustion air may be supplied to the room in which the solid fuel burning appliance is located in lieu of direct ducting, provided that one of the following conditions is met:
	1. The solid fuel burning appliance is part of a central heating plant and installed in an unconditioned space in conformance with the International Mechanical Code; or
	2. The solid fuel burning appliance is installed in existing construction directly on a concrete floor or surrounded by masonry materials as in a fireplace. The combustion air terminus shall be located as close to the solid fuel burning appliance as possible and shall be provided with a barometric damper or equivalent. The combustion air source shall be specified by the manufacturer or no less than 4 inches in diameter or the equivalent in area or as approved.

((R1006.4 Passageway. This section is not adopted.))

NEW SECTION

WAC 51-51-1504Section 1504—Exhaust ducts and exhaust openings.

M1504.3 Exhaust openings. Air exhaust openings shall terminate as follows:

1. Not less than 3 feet (914 mm) from property lines.

2. Not less than 3 feet (914 mm) from gravity air intake openings, operable windows and doors.

3. Not less than 10 feet (3048 mm) from mechanical air intake openings except where either of the following apply:

3.1. The exhaust opening is located not less than 3 feet (914 mm) above the air intake opening.

3.2. The exhaust opening is part of a factory-built intake/exhaust combination termination fitting installed in accordance with the manufacturer's instructions, and the exhaust air is drawn from a living space.

4. Openings shall comply with Sections R303.5.2 and R303.6.

AMENDATORY SECTION(Amending WSR 16-03-025, filed 1/11/16, effective 7/1/16)

WAC 51-51-1507Section M1507—Mechanical ventilation.

M1507.1 General. Local exhaust and whole-house mechanical ventilation systems and equipment shall be designed in accordance with this section.

M1507.2 Recirculation of air. Exhaust air from bathrooms and toilet rooms shall not be recirculated within a residence or to another dwelling unit and shall be exhausted directly to the outdoors. Exhaust air from bathrooms and toilet rooms shall not discharge into an attic, crawl space or other areas of the building.

M1507.3 Whole-house mechanical ventilation system. Whole-house mechanical ventilation systems shall be designed in accordance with Sections M1507.3.1 through M1507.3.3.

M1507.3.1 System design. Each dwelling unit or guestroom shall be equipped with a ventilation system complying with Section M1507.3.4, M1507.3.5, M1507.3.6 or M1507.3.7. Compliance is also permitted to be demonstrated through compliance with the International Mechanical Code or ASHRAE Standard 62.2.

M1507.3.2 Control and operation.

1. Location of controls. Controls for all ventilation systems shall be readily accessible by the occupant.

2. Instructions. Operating instructions for whole-house ventilation systems shall be provided to the occupant by the installer of the system.

3. Local exhaust systems. Local exhaust systems shall be controlled by manual switches, dehumidistats, timers, or other approved means.

4. Continuous whole-house ventilation systems. Continuous whole-house ventilation systems shall operate continuously and be equipped with an override control. A "fan on" switch shall be permitted as an override control. Controls shall be capable of operating the ventilation system without energizing other energy-consuming appliances. ((A clearly visible label shall be affixed to the controls that reads "Whole House Ventilation (see operating instructions)."))Controls shall include text or a symbol indicating their function.

5. Intermittent whole-house ventilation systems. Intermittent whole-house ventilation systems shall comply with the following:

5.1. They shall be capable of operating intermittently and continuously.

5.2. They shall have controls capable of operating the exhaust fans, forced-air system fans, or supply fans without energizing other energy-consuming appliances.

5.3. The ventilation rate shall be adjusted according to the exception in Section 403.8.5.1.

5.4. The system shall be designed so that it can operate automatically based on the type of control timer installed.

5.5. The intermittent mechanical ventilation system shall operate at least one hour out of every four.

5.6. The system shall have a manual control and automatic control, such as a 24-hour clock timer.

5.7. At the time of final inspection, the automatic control shall be set to operate the whole-house fan according to the schedule used to calculate the whole-house fan sizing.

5.8. A label shall be affixed to the control that reads "Whole House Ventilation (see operating instructions)."

M1507.3.2.1 Operating instructions. Installers shall provide the manufacturer's installation, operating instructions, and a whole-house ventilation system operation description.

M1507.3.3 Mechanical ventilation rate. The whole-house mechanical ventilation system shall provide outdoor air to each dwelling unit at a continuous rate of not less than that determined in accordance with Table M1507.3.3(1).

EXCEPTION:

The whole-house mechanical ventilation system is permitted to operate intermittently where the system has controls that enable operation for not less than 25 percent of each 4-hour segment and the ventilation rate prescribed in Table M1507.3.3(1) is multiplied by the factor determined in accordance with Table M1507.3.3(2).

M1507.3.3.1 Testing. Whole-house mechanical ventilation systems shall be tested and verified to provide a flow rate not less than the minimum required by Section M1507.3.3. Testing shall be performed according to the ventilation equipment manufacturer's instructions, or by using a flow hood, flow grid, or other airflow measuring device at the mechanical ventilation fan's inlet terminals or grilles, outlet terminals or grilles or in the connected ventilation ducts. Where required by the building official, testing shall be conducted by an approved third party. A written report of the results of the test shall be signed by the party conducting the test and provided to the building official.

Table M1507.3.3(1)

Continuous Whole-House Mechanical Ventilation System Airflow Rate Requirements

	NUMBER OF BEDROOMS
Dwelling Unit Floor Area (square feet)	0 - 1	2 - 3	4 - 5	6 - 7	˃ 7
	Airflow in CFM
< 1,500	30	45	60	75	90
1,501 - 3,000	45	60	75	90	105
3,001 - 4,500	60	75	90	105	120
4,501 - 6,000	75	90	105	120	135
6,001 - 7,500	90	105	120	135	150
˃ 7,501	105	120	135	150	165

For SI: 1 square foot = 0.0929 m2, 1 cubic foot per minute = 0.0004719 m3/S.

Table M1507.3.3(2)

Intermittent Whole-House Mechanical Ventilation Rate Factorsa, b

Run-Time Percentage in Each 4-Hour Segment	25%	33%	50%	66%	75%	100%
Factora	4	3	2	1.5	1.3	1.0

a	For ventilation system run time values between those given, the factors are permitted to be determined by interpolation.
b	Extrapolation beyond the table is prohibited.

M1507.3.4 Whole-house ventilation using exhaust fans. This section establishes minimum prescriptive requirements for whole-house ventilation systems using exhaust fans. A system which meets all the requirements of this section shall be deemed to satisfy the requirements for a whole-house ventilation system.

M1507.3.4.1 Whole-house ventilation fans. Exhaust fans providing whole-house ventilation shall have a flow rating at 0.25 inches water gauge as specified in Table M1507.3.3(1). Manufacturers' fan flow ratings shall be determined according to HVI 916 or AMCA 210.

M1507.3.4.2 Fan noise. Whole-house fans located 4 feet or less from the interior grille shall have a sone rating of 1.0 or less measured at 0.1 inches water gauge. Manufacturer's noise ratings shall be determined as per HVI 915 (March 2009). Remotely mounted fans shall be acoustically isolated from the structural elements of the building and from attached duct work using insulated flexible duct or other approved material.

M1507.3.4.3 Fan controls. The whole-house ventilation fan shall meet the requirements of Section M1507.3.2 and M1507.3.2.1.

M1507.3.4.4Ventilation openings. Each habitable space shall be provided with outdoor air inlets or operable windows with an openable area not less than 4 square inches of net free area of opening for each 10 cfm of outdoor air required by Table M1507.3.3(1). Where outdoor air supplies are separated from exhaust points by doors, provisions shall be made to ensure air flow by installation of distribution ducts, undercutting doors, installation of grilles, transoms, or similar means. Doors shall be undercut to a minimum of 1/2 inch above the surface of the finish floor covering.

Individual room outdoor air inlets shall:

1. Have controllable and secure openings;

2. Be sleeved or otherwise designed so as not to compromise the thermal properties of the wall or window in which they are placed;

3. Any inlet or combination of inlets which provide 10 cfm at 10 Pascals are deemed equivalent to 4 square inches net free area.

Ventilation opening shall be screened or otherwise protected from entry by leaves or other material. Openings shall be controllable, securable and shall be designed to not compromise the thermal properties of the building envelope. Ventilation openings shall be located so as not to take air from the following areas:

1. Closer than 10 feet from an appliance vent outlet, unless such vent outlet is 3 feet above the outdoor air inlet.

2. Where it will pick up objectionable odors, fumes or flammable vapors.

3. A hazardous or unsanitary location.

4. A room or space having any fuel-burning appliances therein.

5. Closer than 10 feet from a vent opening of a plumbing drainage system unless the vent opening is at least 3 feet above the air inlet.

6. Attic, crawl spaces, or garages.

7. Asphalt roofs unless it is shown that no other location is permissible. In such cases the inlet opening shall be located a minimum of 2 feet from the nearest surface of the asphalt roofing, measured from the intake opening.

M1507.3.5 Whole-house ventilation integrated with a forced-air system. This section establishes minimum prescriptive requirements for whole-house ventilation systems integrated with forced-air ventilation systems. A system which meets all the requirements of this section shall be deemed to satisfy the requirements for a whole-house ventilation system.

M1507.3.5.1 Integrated whole-house ventilation systems. Integrated whole-house ventilation systems shall provide outdoor air at the rate calculated using Section M1507.3.3. Integrated forced-air ventilation systems shall distribute outdoor air to each habitable space through the forced-air system ducts. Integrated forced-air ventilation systems shall have an outdoor air inlet duct connecting a terminal element on the outside of the building to the return air plenum of the forced-air system, at a point within 4 feet upstream of the air handler. The outdoor air inlet duct connection to the return air stream shall be located upstream of the forced-air system blower and shall not be connected directly into a furnace cabinet to prevent thermal shock to the heat exchanger. The system will be equipped with a motorized damper connected to the automatic ventilation control as specified in Section M1507.3.2. The required flow rate shall be verified by field testing with a flow hood or a flow measuring station.

M1507.3.5.2 Ventilation duct insulation. All supply ducts in the conditioned space shall be insulated to a minimum of R-4.

M1507.3.5.3 Outdoor air inlets. Inlets shall be screened or otherwise protected from entry by leaves or other material. Outdoor air inlets shall be located so as not to take air from the following areas:

1. Closer than 10 feet from an appliance vent outlet, unless such vent outlet is 3 feet above the outdoor air inlet.

2. Where it will pick up objectionable odors, fumes or flammable vapors.

3. A hazardous or unsanitary location.

4. A room or space having any fuel-burning appliances therein.

5. Closer than 10 feet from a vent opening of a plumbing drainage system unless the vent opening is at least 3 feet above the air inlet.

6. Attic, crawl spaces, or garages.

M1507.3.6 Whole-house ventilation using a supply fan. This section establishes minimum prescriptive requirements for whole-house ventilation systems using an inline supply fan. A system which meets all the requirements of this section shall be deemed to satisfy the requirements for a whole-house ventilation system.

M1507.3.6.1 Outdoor air. Supply fan ventilation systems shall distribute outdoor air to each habitable space through the forced-air system ducts or through dedicated ducts to each habitable space. Supply fans shall have the capacity to provide the amount of outdoor air specified in Table M1507.3.3(1) at 0.40 inches water gauge as per HVI 916. The outdoor air must be filtered before it is delivered to habitable spaces. The filter may be located at the intake device, in line with the fan, or, in the case of a connection to the return plenum of the air handler, using the furnace filter. An outdoor air inlet shall be connected to either the supply or return air stream.

M1507.3.6.2 Ducts. An outdoor air inlet duct connection to the supply air stream shall be located downstream of the forced-air system blower. An outdoor air inlet duct connection to the return air stream shall be located at least 4 feet upstream of the forced-air system blower and its filter. Neither type of duct shall be connected directly into a furnace cabinet to prevent thermal shock to the heat exchanger. The outdoor air inlet duct shall be prescriptively sized in accordance with Table M1507.3.6.2. The terminal element on the outside of the building shall be sized 2 inches in diameter larger than the outdoor air inlet duct.

Table M1507.3.6.2

Prescriptive Supply Fan Duct Sizing

Supply Fan Tested cfm at 0.40" wg
Specified Volume from Table 1507.3.3(1)	Minimum Smooth Duct Diameter	Minimum Flexible Duct Diameter
50 - 90 cfm	4 inch	5 inch
90 - 150 cfm	5 inch	6 inch
150 - 250 cfm	6 inch	7 inch
250 - 400 cfm	7 inch	8 inch

M1507.3.6.3 Dampers. The system shall be equipped with a back-draft damper and one of the following:

1. A calibrated manual volume damper installed and set to meet the measured flow rates specified in Table M1507.3.3(1) by field testing with a pressure gauge and/or following manufacturer's installation instructions; or

2. A manual volume damper installed and set to meet the measured flow rates specified in Table M1507.3.3(1) by field testing with a flow hood or a flow measuring station; or

3. An automatic flow-regulating device sized to the specified flow rates in Table M1507.3.3(1) which provides constant flow over a pressure range of 0.20 to 0.60 inches water gauge.

M1507.3.6.4 Ventilation duct insulation. All supply ducts in the conditioned space shall be insulated to a minimum of R-4.

M1507.3.6.5 Outdoor air inlets. Inlets shall be screened or otherwise protected from entry by leaves or other material. Outdoor air inlets shall be located so as not to take air from the following areas:

1. Closer than 10 feet from an appliance vent outlet, unless such vent outlet is 3 feet above the outdoor air inlet.

2. Where it will pick up objectionable odors, fumes or flammable vapors.

3. A hazardous or unsanitary location.

4. A room or space having any fuel-burning appliances therein.

5. Closer than 10 feet from a vent opening of a plumbing drainage system unless the vent opening is at least 3 feet above the air inlet.

6. Attic, crawl spaces, or garages.

M1507.3.7 Whole-house ventilation using a heat recovery ventilation system. This section establishes minimum prescriptive requirements for whole-house ventilation using a heat recovery ventilation system.

M1507.3.7.1 Heat recovery ventilation systems. All duct work in heat recovery systems shall be sized and installed per the manufacturer's instructions. System minimum flow rating shall be not less than that specified in Table M1507.3.3(1). Heat recovery ventilation systems shall have a filter on the upstream side of the heat exchanger in both the intake and exhaust airstreams with a minimum efficiency rating value (MERV) of 6.

M1507.3.7.2 Ventilation duct insulation. All supply ducts in the conditioned space installed upstream of the heat exchanger shall be insulated to a minimum of R-4.

M1507.3.7.3 Outdoor air inlets. Inlets shall be screened or otherwise protected from entry by leaves or other material. Outdoor air inlets shall be located so as not to take air from the following areas:

1. Closer than 10 feet from an appliance vent outlet, unless such vent outlet is 3 feet above the outdoor air inlet.

2. Where it will pick up objectionable odors, fumes or flammable vapors.

3. A hazardous or unsanitary location.

4. A room or space having any fuel-burning appliances therein.

5. Closer than 10 feet from a vent opening of a plumbing drainage system unless the vent opening is at least 3 feet above the air inlet.

6. Attic, crawl spaces, or garages.

M1507.4 Local exhaust. Local exhaust shall be provided in each kitchen, bathroom, water closet, laundry room, indoor swimming pool, spa, and other rooms where water vapor or cooking odor is produced. Local exhaust systems shall be designed to have the capacity to exhaust the minimum air flow rate determined in accordance with Table M1507.4.

Table M1507.4

Minimum Required Local Exhaust Rates

For One- and Two-Family Dwellings

Area to Be Exhausted	Exhaust Rates
Kitchens	100 cfm intermittent or 25 cfm continuous
Bathrooms - Toilet rooms Laundry rooms, indoor swimming pools, and spas	Mechanical exhaust capacity of 50 cfm intermittent or 20 cfm continuous

For SI:

1 cubic foot per minute = 0.0004719 m3/s.

M1507.4.1 Local exhaust fans. Exhaust fans providing local exhaust shall have a minimum fan flow rating not less than 50 cfm at 0.25 inches water gauge for bathrooms, laundries, or similar rooms and 100 cfm at 0.25 inches water gauge for kitchens. Manufacturers' fan flow ratings shall be determined as per HVI 916 (April 1995) or AMCA 210.

EXCEPTION:

Where a range hood or down draft exhaust fan is used to satisfy the local exhaust requirements for kitchens, the range hood or down draft exhaust shall not be less than 100 cfm at 0.10 inches water gauge.

M1507.4.2 Local exhaust controls. Local exhaust systems shall be controlled by manual switches, dehumidistats, timers, or other approved means. Local exhaust system controls shall be readily accessible.

AMENDATORY SECTION(Amending WSR 16-03-025, filed 1/11/16, effective 7/1/16)

WAC 51-51-4400((Reserved.))Referenced standards.

ANCE

NMX-J-521/2-40-ANCE—2019/CAN/CSA-22.2 No. 60335-2-40—19/UL 60335-2-40-2019 Household and Similar Electrical Appliances Safety-Part 2-40-Safety: Particular Requirements for Electric Heat Pumps, Air-Conditioners and Dehumidifiers.

M1403.1, M1412.1, M1413.1

ANSI

LC 1/CSA 6.26—18: Fuel Gas Piping Systems Using Corrugated Stainless Steel Tubing (CSST)

G2414.5.4, G2411.3, G2415.5

403.5.5

ASHRAE

34—2019: Designation and Safety Classification of Refrigerants

ASTM

E2556/E2556M-10: Standard Specification for Vapor Permeable Flexible Sheet Water-Resistive Barriers Intended for Mechanical Attachment.

M1411.1

CSA

CAN/CSA/C22.2 No. 60335-2-40—2012 60335-2-40—2019

NMX-J-521/2-40-ANCE—2019/CAN/CSA-22.2 No. 60335-2-40—19/UL 60335-2-40-2019 Household and Similar Electric Appliances, Part 2-40-Safety: Particular Requirements for Electric Heat Pumps, Air-Conditioners and Dehumidifiers.

M2006.1

UL/CSA/ANCE 60335-2-40—2019 Household and Similar Electrical Appliances Safety- Part 2-40: Particular Requirements for Electrical Heat Pumps, Air Conditioners and Dehumidifiers.

M1403.1, M1412.1, M1413.1

AMENDATORY SECTION(Amending WSR 07-01-090, filed 12/19/06, effective 7/1/07)

WAC 51-51-60103Section AF103—Requirements.

AF103.1 General. The following construction techniques are intended to resist radon entry and prepare the building for post-construction radon mitigation, if necessary (see Figure ((AF102))AF103). These techniques are required in high radon potential counties designated in Table AF101(1).

NEW SECTION

WAC 51-51-60104Appendix Q—Tiny houses.

AQ102 Definitions.

EGRESS ROOF ACCESS WINDOW. This definition is not adopted.

LANDING PLATFORM. This definition is not adopted.

LOFT. This definition is not adopted.

SLEEPING LOFT. A sleeping space on a floor level located more than 30 inches (762 mm) above the main floor and open to the main floor on one or more sides with a ceiling height of less than 6 feet 8 inches (2032 mm).

TINY HOUSE. A dwelling unit that is 400 square feet (37 m2) or less in floor area excluding sleeping lofts.

AQ103.1 Minimum ceiling height. Habitable space in tiny houses shall have a ceiling height of not less than 6 feet 8 inches (2032 mm). Bathrooms, toilet rooms and kitchens shall have a ceiling height of not less than 6 feet 4 inches (1930 mm). Obstructions including, but not limited to, beams, girders, ducts and lighting, shall not extend below these minimum ceiling heights.

EXCEPTION:

Ceiling heights in sleeping lofts shall be in accordance with Section R326.

AQ103 Ceiling height. This section is not adopted.

AQ104 Energy conservation.

AQ104.1 Air leakage testing. The air leakage rate for tiny houses shall not exceed 0.30 cfm at 50 Pascals of pressure per feet of the dwelling unit enclosure area. Testing shall be conducted in accordance with RESNET/ICC 380, ASTM E 779 or ASTM E 1827 and reported at a pressure of 0.2 inch w.g. (50 Pascals). Where required by the code official, testing shall be conducted by an approved third party. A written report of the results of the test shall be signed by the party conducting the test and provided to the code official. Testing shall be performed after the continuous air barrier, including all penetrations, is completed and sealed.

During testing:

1. Exterior windows and doors, fireplace and stove doors shall be closed, but not sealed, beyond the intended weather stripping or other infiltration control measures.

2. Dampers including exhaust, intake, makeup air, backdraft and flue dampers shall be closed, but not sealed beyond intended infiltration control measures.

3. Interior doors, if installed at the time of the test, shall be open.

4. Exterior louvers for continuous ventilation systems and heat recovery ventilators shall be closed and sealed.

5. Heating and cooling systems, if installed at the time of the test, shall be turned off.

6. Supply and return registers, if installed at the time of the test, shall be fully open.

AQ104 Lofts. This section is not adopted.

AQ104.1.1 Whole house mechanical ventilation. Where an air leakage rate not exceeding 0.30 cfm per ft of the dwelling unit enclosure area in accordance with Section AQ106.1 is provided, the tiny house shall be provided with whole house mechanical ventilation in accordance with Section M1505.4.

AQ104.2 Alternative compliance. Tiny houses shall be deemed to be in compliance with the Washington State Energy Code – Residential (WSEC-R) and Chapter R4 of the International Energy Conservation Code provided that all the following conditions are met:

1. The insulation and fenestration meet the requirements of IECC Table R402.1.2.

2. The thermal envelope meets the requirements of IECC Table R402.4.1.1 and IECC Table R402.4.1.1.

3. Solar, wind, or other renewable energy source supplies not less than 5 watts per square foot of floor area for the structure.

4. Permanently installed lighting is in accordance with Section R404.

5. Mechanical ventilation is provided in accordance with Section M1505 of this code. Operable fenestration is not used as the outdoor air source for the mechanical ventilation.

Figure for R326.2.3

AQ105 Emergency escape and rescue openings. This section is not adopted.

AMENDATORY SECTION(Amending WSR 16-03-025, filed 1/11/16, effective 7/1/16)

WAC 51-51-60105Appendix ((Q))U—Dwelling unit fire sprinkler systems.

The design and installation of residential fire sprinkler systems shall be in accordance with the ((2015))2018 International Residential Code Section P2904 Dwelling Unit Fire Sprinkler Systems.

AMENDATORY SECTION(Amending WSR 16-03-025, filed 1/11/16, effective 7/1/16)

WAC 51-51-60107Appendix V—Fire sprinklers.

The provisions contained in this appendix are not mandatory unless specifically referenced in the adopting ordinance.

AV107.1 Fire sprinklers. An approved automatic fire sprinkler system shall be installed in new one-family and two-family dwellings and townhouses in accordance with Appendix ((Q))U.