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 106Construction 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 R202Definitions.
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 R302Fire-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.
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.
R302.2.3 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 R303Light, 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 R308Glazing.))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 3100Emergency 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 R313Automatic 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 R314Smoke 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 R315Carbon 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 R324Solar 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.
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.
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.
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.
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:
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.
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;
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;
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.
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 1-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.
NEW SECTION
WAC 51-51-0331Section R331Protection 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 R403Footings.
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 R507Decks.
((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