PROPOSED RULES
Original Notice.
Preproposal statement of inquiry was filed as WSR 06-07-126.
Title of Rule and Other Identifying Information: Amendment of chapter 51-51 WAC, adoption and amendment of the 2006 Edition of the International Residential Code (IRC).
Hearing Location(s): Spokane City Council Chambers, West 808 Spokane Falls Boulevard, Spokane, WA, on September 8, 2006, at 10:00 a.m.; and at the Holiday Inn Select Renton, One Grady Way South, Renton, WA, on October 13, 2006, at 10:00 a.m.
Date of Intended Adoption: November 17, 2006.
Submit Written Comments to: John Neff, Council Chair, P.O. Box 42525, Olympia, WA 98504-2525, e-mail sbcc@cted.wa.gov, fax (360) 586-9383, by October 13, 2006.
Assistance for Persons with Disabilities: Contact Sue Mathers by August 31, 2006, TTY (360) 586-0772 or (360) 725-2966.
Purpose of the Proposal and Its Anticipated Effects, Including Any Changes in Existing Rules: The proposed rules adopt the most recently published edition of the IRC and make changes to the state amendments to this code.
1. WAC 51-51-003 International Residential Code: Adopts by reference the 2006 edition of the International Residential Code, excluding chapters 11 and 25 through 42. References appropriate regulations for plumbing, energy and electrical codes.
2. WAC 51-51-008 Implementation: Sets an effective date of July 1, 2007.
3. Section R102 Applicability: Specifies that appendices do not apply unless adopted locally, and approved by the state building code council. Retains amendment related to moved buildings in accordance with RCW 19.27.180.
4. Section R202 Definitions: Retains existing amendments and adds definitions of "dwelling unit" and "small business."
5. Section R310.6 Access to emergency escape and rescue openings: Requires a firm level base on the ground below escape and rescue openings for ladder access.
6. Section R311 Means of egress: Retains and makes editorial corrections to section exempting limited areas in dwellings from stairway requirements.
7. Section R313 Smoke alarms: Moves smoke alarm requirements specific to family child day care homes to section regulating dwelling units.
8. Section R317.2 Townhouses: Provides for continuity in the fire resistant wall between townhouses where a story extends beyond the story below.
9. Section R325 Adult family homes: Retains state amendment related to adult family homes in a new section.
10. Section R326 Family child day care homes: Retains state amendment related to family child day care homes in a new section.
11. Section R327 Protection against radon: Adopts the radon control methods of Appendix F for high radon potential counties.
12. Sections R403 and R404 Footings and Foundations; Sections R602.3; R602.10; R602.11 Wood Wall Bracing: Option 1 revises sections on footings and foundations and wood wall bracing to eliminate overlapping provisions for the support of interior braced walls by continuous footings and foundations. Option 2 modifies Option 1 and addresses additional provisions for lateral support of foundation walls.
13. Section R408 Under-floor space: Revises amount of opening area required for under-floor ventilation.
14. Section R613 Exterior windows and glass doors: Provides an exception to the testing requirements for windows and glass doors manufactured by a small business.
15. Section R703 Exterior wall covering: This section includes new requirements in the 2006 IRC for a means of draining water that enters the exterior wall envelope, where water resistive barriers are required, and requirements for flashing.
16. Section R806 -- Roof ventilation: This section, allowing unvented attic spaces, is not adopted.
17. Section M1201 -- General: Provides standards required for liquid petroleum gas (propane) installations consistent with RCW 19.27.031.
18. Chapter 43 -- Referenced standards: Retains test standard for emissions from fireplaces.
19. Appendix F radon control methods: Identifies high radon potential counties, and for those counties requires compliance with construction techniques in this appendix.
Reasons Supporting Proposal: RCW 19.27.031 and 19.27.074.
Statutory Authority for Adoption: RCW 19.27.031 and 19.27.074.
Statute Being Implemented: Chapters 19.27 and 34.05 RCW.
Rule is not necessitated by federal law, federal or state court decision.
Agency Comments or Recommendations, if any, as to Statutory Language, Implementation, Enforcement, and Fiscal Matters: The council is seeking comments on the issues proposed in the following rules.
Name of Proponent: Washington state building code council, governmental.
Name of Agency Personnel Responsible for Drafting and Implementation: Tim Nogler, P.O. Box 42525, Olympia, WA 98504-2525, (360) 725-2969; and Enforcement: Local jurisdictions.
No small business economic impact statement has been prepared under chapter 19.85 RCW. This rule will update the adoption of model codes to stay current with national standards for the benefit of industry and Washington state interests. New state amendments clarify and simplify the code. Where disproportionate economic impact on small business was identified, proposed amendments mitigate the impact by providing an exemption for small business.
A cost-benefit analysis is not required under RCW 34.05.328. The state building code council is not listed in this section as one of the agencies required to comply with this statute.
August 1, 2006
John P. Neff
Council Chair
OTS-9020.3
AMENDATORY SECTION(Amending WSR 04-01-109, filed 12/17/03,
effective 7/1/04)
WAC 51-51-003
International Residential Code.
The
((2003)) 2006 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 42 of
this code are not adopted. Energy Code is regulated by
chapter 51-11 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.
[Statutory Authority: RCW 19.27.031 and 19.27.074. 04-01-109, § 51-51-003, filed 12/17/03, effective 7/1/04.]
[Statutory Authority: RCW 19.27.031 and 19.27.074. 04-01-109, § 51-51-008, filed 12/17/03, effective 7/1/04.]
R102.5 Appendices. Provisions in the appendices shall not
apply unless specifically referenced in the adopting
ordinance. An appendix adopted by a local jurisdiction shall
not be effective unless approved by the state building code
council pursuant to RCW 19.27.060 (1)(a).
R102.7.2 Moved buildings. Buildings or structures moved into
or within a jurisdiction shall comply with the provisions of
this code, the International Building Code (chapter 51-50 WAC), the International Mechanical Code (chapter 51-52 WAC),
the International Fire Code (chapter 51-54 WAC), the Uniform
Plumbing Code and Standards (chapters 51-56 and 51-57 WAC),
the Washington State Energy Code (chapter 51-11 WAC) and the
Washington State Ventilation and Indoor Air Quality Code
(chapter 51-13 WAC) for new buildings or structures.
| EXCEPTION: | Group R-3 buildings or structures are not required to comply if: |
| 1. The original occupancy classification is not changed; and | |
| 2. The original building is not substantially remodeled or rehabilitated. |
[Statutory Authority: RCW 19.27.031 and 19.27.074. 04-01-109, § 51-51-0102, filed 12/17/03, effective 7/1/04.]
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.
CHILD DAY CARE, shall, for the purposes of these regulations,
mean the care of children during any period of a 24 hour day.
CHILD DAY CARE HOME, FAMILY is a child day care facility, licensed
by the 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.
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 (46.4m2).
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, or which has a million
dollars or less per year in gross sales, of window products.
UNUSUALLY TIGHT CONSTRUCTION. Construction meeting the following
requirements:
1. Walls exposed to the outside atmosphere having a continuous water vapor retarder with a rating of 1 perm (57 ng/s·m˛·Pa) or less with openings gasketed or sealed;
2. Openable windows and doors meeting the air leakage requirements of the International Energy Conservation Code, Section 502.1.4; and
3. Caulking or sealants are applied to areas such as joints around window and door frames, between sole plates and floors, between wall-ceiling joints, between wall panels, at penetrations for plumbing, electrical and gas lines, and at other openings; or
4. Buildings built in compliance with the 1986 or later editions of the Washington State Energy Code chapter 51-11 WAC, Northwest Energy Code, or Super Good Cents weatherization standards or equivalent.
[Statutory Authority: RCW 19.27.031 and 19.27.074. 04-01-109, § 51-51-0202, filed 12/17/03, effective 7/1/04.]
R310.6 Access to emergency escape and rescue openings. An
approved firm level base for ground ladder access shall be
provided below emergency escape and rescue openings when
required by the fire code official.
| EXCEPTION: | One- and two-family buildings equipped throughout with an approved automatic sprinkler system installed in accordance with IFC 903.3.1.3. |
[]
R311.1 General. Stairways, ramps, exterior exit balconies,
hallways and doors shall comply with this section.
| EXCEPTION: | Stairs or ladders within an individual dwelling unit used (( |
[Statutory Authority: RCW 19.27.031 and 19.27.074. 04-01-109, § 51-51-0311, filed 12/17/03, effective 7/1/04.]
((R313.3 Family child day care homes. In family child day
care homes operable smoke alarms shall be located in all
sleeping and napping areas. When the family child day care
home has more than one story, and in family child day care
homes with basements, an operable smoke alarm shall be
installed on each story and in the basement. In family child
day care homes where a story or basement is split into two or
more levels, the smoke alarm shall be installed in the upper
level, except that when the lower level contains a sleeping or
napping area, an operable smoke alarm shall be located on each
level. When sleeping rooms are on an upper level, the smoke
alarm shall be placed at the ceiling of the upper level in
close proximity to the stairway. In family child day care
homes where the ceiling height of a room open to the hallway
serving the bedrooms exceeds that of the hallway by 24 inches
or more, smoke alarms shall be installed in the hallway and
the adjacent room. Smoke alarms shall sound an alarm audible
in all areas of the building.)) R313.2 Location. Smoke alarms
shall be installed in the following locations:
1. In each sleeping room.
2. Outside each separate sleeping area in the immediate vicinity of the bedrooms.
3. On each additional story of the dwelling, including basements 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. In napping areas in family child day care homes.
When more than one smoke alarm is required to be installed within an individual dwelling unit, 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 unit.
[Statutory Authority: RCW 19.27.031 and 19.27.074. 04-01-109, § 51-51-0313, filed 12/17/03, effective 7/1/04.]
R317.2 Townhouses. Each townhouse shall be considered a
separate building and shall be separated by
fire-resistance-rated wall assemblies meeting the requirements
of Section R302 for exterior walls.
| EXCEPTION: | A common 2-hour fire-resistance-rated wall is permitted for townhouses if such walls do not contain plumbing or mechanical equipment, ducts or vents in the cavity of the common wall. Penetrations of electrical outlet boxes shall be in accordance with Section R317.3. |
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; or
2. The underside of the exposed floor-ceiling assembly shall be protected as required for projections in Section R302.
[]
ADULT FAMILY ((CHILD DAY CARE)) HOMES
Basements located more than 4 feet below grade level
shall not be used for family child day care homes 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 National Fire
Protection Association Standard 13d.
Floors located more than 4 feet above grade level shall
not be occupied by children in family day care homes.
R325.2 Submittal Standards. In addition to those requirements
in Section 106.1, the submittal shall identify the project as
a Group R-3 Adult Family Home Occupancy. A floor plan shall
be submitted identifying the means of egress and the
components in the means of egress such as stairs, ramps,
platform lifts and elevators. The plans shall indicate the
rooms used for clients and the sleeping room classification of
each room.
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 R311.6 is provided.
3. Type NS2 - where two means of egress are at grade level or ramps constructed in accordance with R311.6 are provided.
R325.4 Types of Locking Devices. All bedroom and bathroom
doors shall be openable from the outside when locked.
Every closet shall be readily openable from the inside.
R325.5 Smoke Alarm Requirements. All adult family homes shall
be equipped with smoke alarms installed as required in Section
R313. Alarms shall be installed in such a manner so that the
fire warning may be audible in all parts of the dwelling upon
activation of a single device.
R325.6 Escape Windows and Doors. Every sleeping room shall be
provided with emergency escape and rescue windows as required
by Section R310.
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.
[Statutory Authority: RCW 19.27.031 and 19.27.074. 04-01-109, § 51-51-0325, filed 12/17/03, effective 7/1/04.]
FAMILY CHILD DAY CARE HOMES
Basements located more than 4 feet below grade level shall not be used for family child day care homes 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 National Fire Protection Association Standard 13d.
Floors located more than 4 feet above grade level shall not be occupied by children in family day care homes.
| EXCEPTIONS: | 1. Use of toilet facilities while under supervision of an adult staff person. |
| 2. Family child day care homes 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 National Fire Protection Association Standard 13d. |
| EXCEPTION: | Sleeping or napping rooms having doors leading to two separate means of egress, or a door leading directly to the exterior of the building. |
| EXCEPTION: | 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. |
[]
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.
[]
OPTION 1SECTIONS 0403 AND 0404
NEW SECTION
WAC 51-51-0403
Section R403 -- Footings.
R403.1 General. All exterior walls shall be supported on
solid or fully grouted masonry or concrete footings, wood
foundations, or other approved structural systems of
sufficient design to accommodate all loads specified in
Section R301 and to transmit the resulting loads to the
supporting soil within the limitations determined from the
characteristics of the soil. Footings shall be supported on
undisturbed natural soil or fill soils in accordance with
Section R401.2.
| EXCEPTION: | Foundation walls complying with Section R404 or stem walls complying with Section R403.1.3 shall be permitted to support exterior walls provided they are supported by footings. |
| EXCEPTIONS: | 1. At buildings in Seismic Design Categories D0 and D1, and at one-story buildings in Seismic Design Category D2, interior braced wall panels are not required to be supported by foundations, provided no building plan dimension perpendicular to the interior braced wall lines is greater than 50 feet. |
| 2. At two-story buildings in Seismic Design Category D2, interior braced wall panels are not required to be supported by foundations, provided all of the following conditions are met: | |
| 2.1. No building plan dimension perpendicular to the interior braced wall lines exceeds 50 feet; | |
| 2.2. The distances between braced wall lines do not exceed twice the building width measured parallel to the braced wall lines; | |
| 2.3. The braced wall panels at the first story are continuously supported by floor joists, blocking or floor beams; and | |
| 2.4. The heights of braced wall panels in under-floor spaces do not exceed 48 inches (1219 mm). |
| EXCEPTION: | In under-floor spaces, braced wall panels shall be permitted to substitute for the foundation wall provided they comply with the following: |
| 1. They are located directly below the braced wall panels above; | |
| 2. They are in accordance with Sections R602.10.2 and R602.10.9.4 for cripple wall bracing; and | |
| 3. They are supported by footings complying with Sections R402 and R403. |
R403.1.2.3 Footing size. In addition to the requirements of
Section R403.1.1, footings shall be constructed beyond the
ends of foundation walls, stem walls and cripple walls
supporting braced wall panels for a minimum distance of 4
inches and a maximum distance of the footing thickness.
R403.1.3 Concrete reinforcement in Seismic Design Categories
D0, D1 and D2. Concrete footings of buildings assigned to
Seismic Design Categories D0, D1 and D2 shall comply with this
section and have minimum reinforcement as specified by Section
R403.1.3.1 or R403.1.3.2. Bottom reinforcement shall be
located 3 inches (76 mm) to 4 inches (102 mm) from the bottom
of the footing.
Where a construction joint is created between a concrete footing and a concrete stem wall, minimum vertical reinforcement of one No. 4 bar shall be installed at not more than 4 feet (1219 mm) on center. The bars shall extend to 3 inches (76 mm) clear of the bottom of the footing, have a standard hook, and extend into the stem wall the lesser of 2 inches (49 mm) clear of the top of the wall and 14 inches (357 mm).
Where a solidly grouted masonry stem wall is supported on a concrete footing, minimum vertical reinforcement of one No. 4 bar shall be installed at not more than 4 feet (1219 mm) on center. The bars shall extend to 3 inches (76 mm) clear of the bottom of the footing, have a standard hook, and extend into the stem wall the lesser of 2 inches (49 mm) clear of the top of the wall and 14 inches (357 mm).
Masonry stem walls without solid grout or vertical reinforcing are not permitted.
Concrete and masonry stem walls shall comply with the requirements of Section R404 for foundation walls.
| EXCEPTION: | In detached one- and two-family dwellings of light-framed construction and three stories or less above grade, plain concrete footings supporting walls, columns or pedestals are permitted. |
R403.1.3.2 Slabs-on-ground with turned-down footings.
Slabs-on-ground with turned-down footings shall have a minimum
of one No. 4 bar located 3 inches (76 mm) to 4 inches (102 mm)
from the top and bottom of the footing.
| EXCEPTION: | For slabs-on-ground cast monolithically with a footing, one No. 5 bar or two No. 4 bars shall be located in the middle third of the footing depth. |
R403.1.4.1 Frost protection. Except where otherwise protected
from frost, foundations, piers and other permanent supports of
buildings and structures shall be protected from frost by one
or more of the following methods:
1. Extend below the frost line specified in Table R301.2(1);
2. Construct in accordance with Section R403.3;
3. Construct in accordance with ASCE 32; or
4. Erect on solid rock.
| EXCEPTIONS: | 1. Protection of freestanding accessory structures with an area of 600 square feet (56 m2) or less, of light-framed construction, with an eave height of 10 feet (3048 mm) or less shall not be required. |
| 2. Protection of freestanding accessory structures with an area of 400 square feet (37 m2) or less, of other than light-framed construction, with an eave height of 10 feet (3048 mm) or less shall not be required. | |
| 3. Decks not supported by a dwelling need not be provided with footings that extend below the frost line. | |
| Footings shall not bear on frozen soil unless the frozen condition is permanent. |
The wood sill plate shall be anchored to the footing or foundation with anchor bolts spaced a maximum of 6 feet (1829 mm) on center. There shall be a minimum of two bolts per plate section with one bolt located not more than 12 inches (305 mm) and not less than seven bolt diameters from each end of the plate section. Bolts shall be at least 1/2 inch (13 mm) in diameter and shall extend a minimum of 7 inches (178 mm) into masonry or concrete. A nut and washer shall be tightened to a snug-tight condition on each bolt to the plate.
Cold-formed steel framing systems shall be fastened to wood sill plates or anchored directly to the foundation in accordance with Section R505.3.1 or R603.3.1.
| EXCEPTIONS: | 1. Anchorage, spaced as required to provide equivalent anchorage to 1/2-inch-diameter (13 mm) anchor bolts. |
| 2. Walls 24 inches (610 mm) or less in length connecting offset braced wall panels shall be anchored to the footing or foundation with a minimum of one anchor bolt located in the center third of the plate section and shall be attached to adjacent braced wall panels as specified in Figure R602.10.5 at the corners. | |
| 3. Walls 12 inches (305 mm) or less in length connecting offset braced wall panels shall be permitted to be connected to the footing or foundation without anchor bolts. The wall shall be attached to adjacent braced wall panels as specified in Figure R602.10.5 at the corners. |
1. Interior braced wall sill plates shall be anchored to footings or foundations with anchor bolts spaced at not more than 6 feet (1829 mm) on center, and located not more than 12 inches (305 mm) and not less than seven bolt diameters from the ends of each plate section, when supported on a foundation.
2. The maximum anchor bolt spacing shall be 4 feet (1219 mm) for buildings over two stories in height.
3. Plate washers complying with Section R602.11.1 shall be installed on the anchor bolts over the full length of required braced wall panels. Properly sized cut washers shall be permitted for anchor bolts in wall lines not containing braced wall panels.
4. Stepped cripple walls shall comply with Section R602.11.3.
5. Where wood foundations in accordance with Sections R402.1 and R404.2 are used, the force transfer shall have a capacity equal to or greater than the connections required by Section R602.11.1 or the braced wall panel shall be connected to the wood foundations in accordance with the braced wall panel-to-floor fastening requirements of Table 602.3(1).
[]
R404.1.4 Seismic Design Categories D0, D1 and D2. In addition
to the requirements of Tables R404.1.1(1) and R404.1.1(5),
plain concrete and plain masonry foundation walls located in
Seismic Design Categories D0, D1 and D2 shall comply with the
following:
1. Wall height shall not exceed 8 feet (2438 mm).
2. Unbalanced backfill height shall not exceed 4 feet (1219 mm).
3. Minimum reinforcement for plain concrete foundation walls shall consist of one No. 4 (No. 13) horizontal bar located in the upper 12 inches (305 mm) of the wall.
4. Minimum thickness for plain concrete foundation walls shall be 7.5 inches (191 mm) except that 6 inches (152 mm) is permitted when the maximum height is 4 feet, 6 inches (1372 mm).
5. Minimum nominal thickness for plain masonry foundation walls shall be 8 inches (203 mm).
6. Masonry stem walls shall have a minimum vertical reinforcement of one No. 4 (No. 13) bar located a maximum of 4 feet (1220 mm) on center in grouted cells. Vertical reinforcement shall be tied to the horizontal reinforcement in the footings.
Foundation walls located in Seismic Design Categories D0, D1 and D2, supporting more than 4 feet (1219 mm) of unbalanced backfill or exceeding 8 feet (2438 mm) in height shall be constructed in accordance with Table R404.1.1(2), R404.1.1(3) or R404.1.1(4) for masonry, or Table R404.1.1(5) for concrete. Where Table R404.1.1(5) permits plain concrete walls, not less than No. 4 (No. 13) vertical bars at a spacing not exceeding 48 inches (1219 mm) shall be provided. Insulating concrete form foundation walls shall be reinforced as required in Table R404.4(1), R404.4(2), R404.4(3), R404.4(4) or R404.4(5). Where no vertical reinforcement is required by Table R404.4(2), R404.4(3) or R404.4(4) there shall be a minimum of one No. 4 (No. 13) bar at 48 inches (1220 mm) on center. All concrete and masonry foundation walls shall have two No. 4 (No. 13) horizontal bars located in the upper 12 inches (305 mm) of the wall.
R404.3 Wood sill plates. Wood sill plates shall be a minimum
of 2-inch by 4-inch nominal lumber. Sill plate anchorage
shall be in accordance with Sections R403.1.6 and R602.11.
[]
OPTION 2SECTIONS 0403 AND 0404
NEW SECTION
WAC 51-51-0403
Section R403 -- Footings.
R403.1 General. All exterior walls shall be supported on
continuous solid or fully grouted masonry or concrete
footings, wood foundations, or other approved structural
systems of sufficient design to accommodate all loads
specified in Section R301 and to transmit the resulting loads
to the supporting soil within the limitations determined from
the characteristics of the soil. Footings shall be supported
on undisturbed natural soil or fill soils in accordance with
Section R401.2. Foundation walls complying with Section R404
or stem walls complying with Section R403.1.3 shall be
permitted to support exterior walls and exterior braced wall
panels provided they are supported by footings.
R403.1.2 Braced Wall Panels in Seismic Design Categories D0, D1
and D2. The braced wall panels at exterior and interior walls
of buildings located in Seismic Design Categories D0, D1 and D2
shall be supported by foundations.
| EXCEPTIONS: | 1. At buildings in Seismic Design Categories D0 and D1, and at one-story buildings in Seismic Design Category D2, interior braced wall panels are not required to be supported by foundations, provided no building plan dimension perpendicular to the interior braced wall lines is greater than 50 feet. |
| 2. At two-story buildings in Seismic Design Category D2, interior braced wall panels are not required to be supported by foundations, provided all of the following conditions are met: | |
| 2.1. No building plan dimension perpendicular to the interior braced wall lines exceeds 50 feet; | |
| 2.2. The distances between braced wall lines do not exceed twice the building width measured parallel to the braced wall lines; | |
| 2.3. The braced wall panels at the first story are continuously supported by floor joists, blocking or floor beams; and | |
| 2.4. The heights of braced wall panels in under-floor spaces do not exceed 48 inches (1219 mm). |
| EXCEPTIONS: | 1. Footings of foundations supporting interior braced wall panels are not required to be continuous but shall be constructed beyond the ends of foundation walls, stem walls and cripple walls supporting braced wall panels for a minimum distance of 4 inches and a maximum distance of the footing thickness. |
| 2. In under-floor spaces, cripple walls shall be permitted to substitute for masonry or concrete foundation walls provided they comply with the following: | |
| a. They are located directly below the interior braced wall panels above; | |
| b. They are braced in accordance with Sections R602.10.2 and R602.10.11.4 for cripple wall bracing; and | |
| c. They are supported by footings complying with Sections R402 and R403, except that the footing of a foundation supporting an interior braced wall panel is not required to be continuous. |
Where a construction joint is created between a concrete footing and a concrete stem wall, minimum vertical reinforcement of one No. 4 bar shall be installed at not more than 4 feet (1219 mm) on center. The bars shall extend to 3 inches (76 mm) clear of the bottom of the footing, have a standard hook, and extend into the stem wall the lesser of 2 inches (49 mm) clear of the top of the wall and 14 inches (357 mm).
Where a solidly grouted masonry stem wall is supported on a concrete footing, minimum vertical reinforcement of one No. 4 bar shall be installed at not more than 4 feet (1219 mm) on center. The bars shall extend to 3 inches (76 mm) clear of the bottom of the footing, have a standard hook, and extend into the stem wall to 2 inches (49 mm) clear of the top of the wall.
Masonry stem walls without solid grout and vertical reinforcing are not permitted.
Concrete and masonry stem walls shall comply with the
requirements of Section R404 for foundation walls.
| EXCEPTION: | In detached one- and two-family dwellings of light-framed construction and three stories or less above grade plain concrete footings supporting walls, columns or pedestals are permitted. |
R403.1.3.2 Slabs-on-ground with turned-down footings.
Slabs-on-ground with turned-down footings shall have a minimum
of one No. 4 bar located 3 inches (76 mm) to 4 inches (102 mm)
from the top and bottom of the footing.
| EXCEPTION: | For slabs-on-ground cast monolithically with a footing, one No. 5 bar or two No. 4 bars shall be located in the middle third of the footing depth. |
R403.1.4.1 Frost protection. Except where otherwise protected
from frost, foundations, piers and other permanent supports of
buildings and structures shall be protected from frost by one
or more of the following methods:
1. Extend below the frost line specified in Table R301.2(1);
2. Construct in accordance with Section R403.3;
3. Construct in accordance with ASCE 32; or
4. Erect on solid rock.
| EXCEPTIONS: | 1. Protection of freestanding accessory structures with an area of 600 square feet (56 m2) or less, of light-framed construction, with an eave height of 10 feet (3048 mm) or less shall not be required. |
| 2. Protection of freestanding accessory structures with an area of 400 square feet (37 m2) or less, of other than light-framed construction, with an eave height of 10 feet (3048 mm) or less shall not be required. | |
| 3. Decks not supported by a dwelling need not be provided with footings that extend below the frost line. | |
| Footings shall not bear on frozen soil unless the frozen condition is a permanent. |
The wood sole or sill plate shall be anchored to the monolithic slab, footing or foundation with anchor bolts spaced a maximum of 6 feet (1829 mm) on center. There shall be a minimum of two bolts per plate section with one bolt located not more than 12 inches (305 mm) and not less than seven bolt diameters from each end of the plate section. Bolts shall be at least 1/2 inch (13 mm) in diameter and shall extend a minimum of 7 inches (178 mm) into masonry or concrete. A nut and washer shall be tightened to a snug-tight condition on each bolt to the plate.
Cold-formed steel framing systems shall be fastened to
wood sill plates or anchored directly to the foundation in
accordance with Section R505.3.1 or R603.3.1.
| EXCEPTIONS: | 1. Anchorage, spaced as required to provide equivalent anchorage to 1/2-inch-diameter (13 mm) anchor bolts. |
| 2. Walls 24 inches (610 mm) or less in length connecting offset braced wall panels shall be anchored to the footing or foundation with a minimum of one anchor bolt located in the center third of the plate section and shall be attached to adjacent braced wall panels as specified in Figure R602.10.5 at the corners. | |
| 3. Walls 12 inches (305 mm) or less in length connecting offset braced wall panels shall be permitted to be connected to the footing or foundation without anchor bolts. The wall shall be attached to adjacent braced wall panels as specified in Figure R602.10.5 at the corners. |
1. Interior braced wall sill plates shall be anchored to footings or foundations with anchor bolts spaced at not more than 6 feet (1829 mm) on center, and located not more than 12 inches (305 mm) and not less than seven bolt diameters from the ends of each plate section, when required to be supported on a foundation.
2. The maximum anchor bolt spacing shall be 4 feet (1219 mm) for buildings over two stories in height.
3. Plate washers complying with Section R602.11.1 shall be installed on the anchor bolts over the full length of required braced wall panels. Properly sized cut washers shall be permitted for anchor bolts in wall lines not containing braced wall panels.
4. Stepped cripple walls shall comply with Section R602.11.3.
5. Where wood foundations in accordance with Sections R402.1 and R404.2 are used, the force transfer shall have a capacity equal to or greater than the connections required by Section R602.11.1 or the braced wall panel shall be connected to the wood foundations in accordance with the braced wall panel-to-floor fastening requirements of Table 602.3(1).
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R404.1 Concrete and masonry foundation walls. Concrete and
masonry foundation walls shall be selected and constructed in
accordance with the provisions of Section R404 or in
accordance with ACI 318, ACI 332, NCMA TR68-A or ACI 530/ASCE
5/TMS 402 or other approved structural standards. When ACI
318, ACI 332 or ACI 530/ASCE 5/TMS 402 or the provisions of
Section R404 are used to design concrete or masonry foundation
walls, project drawings, typical details and specifications
are not required to bear the seal of the architect or engineer
responsible for the design, unless otherwise required by the
state law of the jurisdiction having authority.
Foundation walls that meet all of the following shall be considered laterally supported:
1. Full basement floor shall be 3.5 inches (89 mm) thick concrete slab poured tight against the bottom of the foundation wall.
2. Floor joists and blocking shall be connected to the sill plate at the top of the wall by the prescriptive method called out in Table R404.1(1), or; shall be connected with an approved connector with listed capacity meeting Table 404.1(1).
3. Bolt spacing for the sill plate shall be no greater than per Table R404.1(2).
4. Floor shall be blocked perpendicular to the floor joists. Blocking shall be full depth within two joist spaces of the foundation wall, and be flat-blocked with minimum 2-inch by 4-inch (51 mm by 102 mm) blocking elsewhere.
5. Where foundation walls support unbalanced load on opposite sides of the building, such as a daylight basement, the building aspect ratio, L/W, shall not exceed the value specified in Table R404.1(3). For such foundation walls, the rim board shall be attached to the sill with a 20 gage metal angle clip at 24 inches (610 mm) on center, with five 8d nails per leg, or an approved connector supplying 230 pounds per linear foot (3.36 kN/m) capacity.
| EXCEPTION: | Foundations constructed entirely of concrete with stem walls not exceeding 5 feet (1524 mm) in height and supporting less than 4 feet (1220 mm) of unbalanced backfill are exempt from the lateral bracing requirements of Section R404.1. |
1. Wall height shall not exceed 8 feet (2438 mm).
2. Unbalanced backfill height shall not exceed 4 feet (1219 mm).
3. Minimum reinforcement for plain concrete foundation walls shall consist of one No. 4 (No. 13) horizontal bar located in the upper 12 inches (305 mm) of the wall.
4. Minimum thickness for plain concrete foundation walls shall be 7.5 inches (191 mm) except that 6 inches (152 mm) is permitted when the maximum height is 4 feet, 6 inches (1372 mm).
5. Minimum nominal thickness for plain masonry foundation walls shall be 8 inches (203 mm).
6. Masonry stem walls shall have a minimum vertical reinforcement of one No. 4 (No. 13) bar located a maximum of 4 feet (1220 mm) on center in grouted cells. Vertical reinforcement shall be tied to the horizontal reinforcement in the footings.
Foundation walls located in Seismic Design Categories D0, D1 and D2, supporting more than 4 feet (1219 mm) of unbalanced backfill or exceeding 8 feet (2438 mm) in height shall be constructed in accordance with Table R404.1.1(2), R404.1.1(3) or R404.1.1(4) for masonry, or Table R404.1.1(5) for concrete. Where Table R404.1.1(5) permits plain concrete walls, not less than No. 4 (No. 13) vertical bars at a spacing not exceeding 48 inches (1219 mm) shall be provided. Insulating concrete form foundation walls shall be reinforced as required in Table R404.4(1), R404.4(2), R404.4(3), R404.4(4) or R404.4(5). Where no vertical reinforcement is required by Table 404.4(2), R404.4(3) or 404.4(4) there shall be a minimum of one No. 4 (No. 13) bar at 48 inches (1220 mm) on center. All concrete and masonry foundation walls shall have two No. 4 (No. 13) horizontal bars located in the upper 12 inches (305 mm) of the wall.
10-INCH MASONRY FOUNDATION WALLS WITH REINFORCING
WHERE d > 6.75 INCHESa
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R408.2 Openings for under-floor ventilation. The minimum net
area of ventilation openings shall not be less than 1 square
foot (0.0929 m2) for each 300 square feet (28 m2) of
under-floor area. In addition, a ground cover that meets the
requirements of Section 502.1.6.7 of the Washington State
Energy Code (chapter 51-11 WAC) shall be installed. One
ventilating opening shall be within 3 feet (914 mm) of each
corner of the building, except one side of the building shall
be permitted to have no ventilation openings. Ventilation
openings shall be covered for their height and width with any
of the following materials provided that the least dimension
of the covering shall not exceed 1/4 inch (6.4 mm):
1. Perforated sheet metal plates not less than 0.070 inch (1.8 mm) thick.
2. Expanded sheet metal plates not less than 0.047 inch (1.2 mm) thick.
3. Cast-iron grill or grating.
4. Extruded load-bearing brick vents.
5. Hardware cloth of 0.035 inch (0.89 mm) wire or heavier.
6. Corrosion-resistant wire mesh, with the least dimension being 1/8 inch (3.2 mm).
[]
OPTION 1SECTIONS R602.3; R602.10; R602.11
NEW SECTION
WAC 51-51-0602
Section R602 -- Wood wall framing.
R602.3 Design and construction. Exterior walls of wood
light-framed construction shall be designed and constructed in
accordance with the provisions of this chapter and Figures
R602.3(1) and R602.3(2) or in accordance with AF&PA's NDS.
Components of exterior walls shall be fastened in accordance
with Table R602.3(1) through R602.3(4). Exterior walls
covered with foam plastic sheathing shall be braced in
accordance with Section R602.10. Structural sheathing shall
be fastened directly to structural framing members.
R602.3.4 Bottom (sole) plate. Studs shall have full bearing
on a 2-inch nominal (38 mm) or larger bottom (sole) plate or
sill plate having a width at least equal to the width of the
studs.
R602.10 Wall bracing. Buildings shall be braced in accordance
with Sections R602.10 through R602.10.8. All exterior walls
shall be braced. Bracing shall be provided at interior walls
spaced in accordance with Section R602.10.1.1. Bracing shall
consist of braced wall lines in accordance with Section
R602.10.1. For buildings in Seismic Design Categories D0, D1
and D2, walls shall be constructed in accordance with the
additional requirements of Sections 602.10.11 through
602.11.3.
R602.10.1 Braced wall lines. Braced wall lines shall consist
of braced wall panels constructed in accordance with Section
R602.10.3. The locations and percentages of bracing shall be
in accordance with Table R602.10.1 and shall be the greater of
that required by the Seismic Design Category and the design
wind speed. Braced wall panels shall begin no more than 12.5
feet (3810 mm) from each end of a braced wall line. Braced
wall panels in a braced wall line shall be in line.
| EXCEPTION: | In a braced wall line, out-of-plane offsets of braced wall panels shall be permitted provided they comply with the following: |
| 1. The offsets between adjacent braced wall panels do not exceed 4 feet (1219 mm) in width; and | |
| 2. The aggregate width of out-of-plane offsets at all the braced wall panels does not exceed 8 feet (2438 mm). |
| EXCEPTIONS: | 1. Spacing of braced wall lines not exceeding 50 feet (15.24 m) shall be permitted where: |
| 1.1. The wall bracing installed equals or exceeds the percentages of bracing specified in Table R602.10.1 multiplied by a factor equal to the braced wall line spacing divided by 35 feet (10.67 m); and | |
| 1.2. The length-to-width ratio of the floor or roof diaphragm does not exceed 3:1. | |
| 2. Spacing of braced wall lines at buildings in Seismic Design Categories D0, D1 and D2 shall comply with Section R602.10.11.1. |
LENGTH REQUIREMENTS FOR BRACED WALL PANELS IN A CONTINUOUSLY SHEATHED WALLa,b,c
a. Linear interpolation shall be permitted.
b. Full-height sheathed wall segments on either side of garage openings that support roofs of light-framed construction only, with roof covering dead loads of 3 psf or less shall be permitted to have a 4:1 height-to-width ratio.
c. Walls on either or both sides of openings in garages attached to fully sheathed dwellings shall be permitted to be built in accordance with Section R602.10.6.2 and Figure R602.10.6.2 except that a single sill plate shall be permitted and two anchor bolts shall be placed at 1/3 points. In addition, tie-down devices shall not be required and the vertical wall segment shall have a maximum 6:1 height-to-width ratio (with height being measured from top of header to the bottom of the sill plate). This option shall be permitted for the first story of two-story applications in Seismic Design Categories A through C.
R602.10.6 Alternate braced wall panel construction methods.
Alternate braced wall panels shall be constructed in
accordance with Sections R602.10.6.1 and R602.10.6.2.
R602.10.6.1 Alternate braced wall panels. Alternate braced
wall lines constructed in accordance with one of the following
provisions shall be permitted to replace each 4 feet (1219 mm)
of braced wall panel as required by Section R602.10.4. The
maximum height and minimum width of each panel shall be in
accordance with Table R602.10.6.
1. In one-story buildings, each panel shall be sheathed on one face with 3/8-inch-minimum-thickness (9.5 mm) wood structural panel sheathing nailed with 8d common or galvanized box nails in accordance with Table R602.3(1) and blocked at all wood structural panel sheathing edges. Two anchor bolts installed in accordance with Figure R403.1(1) shall be provided in each panel. Anchor bolts shall be placed in from each end of the panel a horizontal distance of one-fourth the panel width. Each panel end stud shall have a tie-down device fastened to the foundation, capable of providing an uplift capacity in accordance with Table R602.10.6. The tie-down device shall be installed in accordance with the manufacturer's recommendations. The panels shall be supported directly on a foundation or on floor framing supported directly on a foundation, which is continuous across the entire length of the braced wall line. This foundation shall be reinforced with not less than one No. 4 bar top and bottom. When the continuous foundation is required to have a depth greater than 12 inches (305 mm), a minimum 12-inch by 12-inch (305 mm by 305 mm) continuous footing or turned down footing is permitted at door openings in the braced wall line. This continuous footing or turned down footing shall be reinforced with not less than one No. 4 bar top and bottom. This reinforcement shall be lapped 15 inches (381 mm) with the reinforcement required in the continuous foundation located directly under the braced wall line.
2. In the first story of two-story buildings, each braced wall panel shall be in accordance with Item 1 above, except that the following:
2.1 The wood structural panel sheathing shall be provided on both faces;
2.2 Sheathing edge nailing spacing shall not exceed 4 inches on center; and
2.3 Anchor bolts shall be placed at the center of the panel width and in from each end of the panel a horizontal distance of one-fifth the panel width (three total).
R602.10.6.2 Alternate braced wall panel adjacent to a door or
window opening. Alternate braced wall panels constructed in
accordance with one of the following provisions are also
permitted to replace each 4 feet (1219 mm) of braced wall
panel as required by Section R602.10.4 for use adjacent to a
window or door opening with a full-length header:
1. In one-story buildings, each panel shall have a length of not less than 16 inches (406 mm) and a height of not more than 10 feet (3048 mm). Each panel shall be sheathed on one face with a single layer of 3/8-inch-minimum-thickness (9.5 mm) wood structural panel sheathing nailed with 8d common or galvanized box nails in accordance with Figure R602.10.6.2. The wood structural panel sheathing shall extend up over the solid sawn or glued-laminated header and shall be nailed in accordance with Figure R602.10.6.2. Use of a built-up header consisting of at least two 2 x 12s and fastened in accordance with Table R602.3(1) shall be permitted. A spacer, if used, shall be placed on the side of the built-up beam opposite the wood structural panel sheathing. The header shall extend between the inside faces of the first full-length outer studs of each panel. The clear span of the header between the inner studs of each panel shall be not less than 6 feet (1829 mm) and not more than 18 feet (5486 mm) in length. A strap with an uplift capacity of not less than 1,000 pounds (4448 N) shall fasten the header to the side of the inner studs opposite the sheathing. One anchor bolt not less than 5/8-inch-diameter (16 mm) and installed in accordance with Section R403.1.6 shall be provided in the center of each sill plate. The studs at each end of the panel shall have a tie-down device fastened to the foundation with an uplift capacity of not less than 4,200 pounds (18 683 N).
Where a panel is located on one side of the opening, the header shall extend between the inside face of the first full-length stud of the panel and the bearing studs at the other end of the opening. A strap with an uplift capacity of not less than 1,000 pounds (4448 N) shall fasten the header to the bearing studs. The bearing studs shall also have a tie-down device fastened to the foundation with an uplift capacity of not less than 1,000 pounds (4448 N).
The tie-down devices shall be an embedded strap type, installed in accordance with the manufacturer's recommendations. The panels shall be supported directly on a foundation, which is continuous across the entire length of the braced wall line. This foundation shall be reinforced with not less than one No. 4 bar top and bottom.
Where the continuous foundation is required to have a depth greater than 12 inches (305 mm), a minimum 12-inch by 12-inch (305 mm by 305 mm) continuous footing or turned down footing is permitted at door openings in the braced wall line. This continuous footing or turned down footing shall be reinforced with not less than one No. 4 bar top and bottom. This reinforcement shall be lapped not less than 15 inches (381 mm) with the reinforcement required in the continuous foundation located directly under the braced wall line.
2. In the first story of two-story buildings, each wall panel shall be braced in accordance with Item 1 above, except that each panel shall have a length of not less than 24 inches (610 mm).
R602.10.7 Panel joints. All vertical joints of panel
sheathing shall occur over and be fastened to common studs.
Horizontal joints in braced wall panels shall occur over and
be fastened to common blocking of a minimum 2 inches in
nominal thickness.
| EXCEPTION: | Blocking is not required behind horizontal joints in Seismic Design Categories A and B and detached dwellings in Seismic Design Category C when constructed in accordance with Section R602.10.3, braced-wall-panel construction Method 3 and Table R602.10.1, Method 3, or where permitted by the manufacturer's installation requirements for the specific sheathing material. |
R602.10.9 Interior braced wall support. This section is not
adopted.
R602.10.10 Design of structural elements. This section is not
adopted.
R602.10.11 Bracing in Seismic Design Categories D0, D1 and D2.
Structures located in Seismic Design Categories D0, D1 and D2
shall have exterior and interior braced wall lines in
accordance with Sections R602.10.11.1 through R602.10.11.5.
R602.10.11.1 Braced wall line spacing. Spacing between braced
wall lines in each story shall not exceed 25 feet (7620 mm) on
center in both the longitudinal and transverse directions.
| EXCEPTION: | In one- and two-story buildings, spacing between two adjacent braced wall lines shall not exceed 35 feet (10,363 mm) on center in order to accommodate one single room not exceeding 900 square feet (84 m2) in each dwelling unit. Spacing between all other braced wall lines shall not exceed 25 feet (7620 mm). |
| EXCEPTION: | For braced wall panel construction Method 3 of Section R602.10.3, the braced wall panel shall be permitted to begin no more than 8 feet (2438 mm) from each end of the braced wall line provided one of the following conditions is met: |
| 1. A minimum 24-inch-wide (610 mm) panel is applied to each side of the building corner and the two 24-inch-wide (610 mm) panels at the corner shall be attached to framing in accordance with Figure R602.10.5. | |
| 2. The end of each braced wall panel closest to the corner shall have a tie-down device fastened to the stud at the edge of the braced wall panel closest to the corner and to the foundation or framing below. The tie-down device shall be capable of providing an uplift allowable design value of at least 1,800 pounds (8 kN). The tie-down device shall be installed in accordance with the manufacturer's recommendations. |
R602.10.11.4 Cripple wall bracing. In addition to the
requirements of Section R602.10.2, where interior braced wall
panels occur without a foundation below, the length of
parallel exterior cripple wall bracing shall be one and
one-half times the length required by Table R602.10.1. Where
cripple walls braced using Method 3 of Section R602.10.3
cannot provide this additional length, the capacity of the
sheathing shall be increased by reducing the spacing of
fasteners along the perimeter of each piece of sheathing to 4
inches (102 mm) on center.
R602.10.11.5 Sheathing attachment. Adhesive attachment of
wall sheathing shall not be permitted in Seismic Design
Categories C, D0, D1 and D2.
R602.11 Framing and connections for Seismic Design Categories
D0, D1 and D2. The framing and connection details of buildings
located in Seismic Design Categories D0, D1 and D2 shall be in
accordance with Sections R602.11.1 through R602.11.3.
R602.11.1 Wall anchorage. Sill plates at braced wall panels
shall be anchored to concrete or masonry foundations in
accordance with Sections R403.1.6 and R602.11. For all
buildings in Seismic Design Categories D0, D1 and D2 and
townhouses in Seismic Design Category C, plate washers, a
minimum of 0.229 inch by 3 inches by 3 inches (5.8 mm by 76 mm
by 76 mm) in size, shall be installed between the foundation
sill plate and the nut. The hole in the plate washer is
permitted to be diagonally slotted with a width of up to 3/16
inch (5 mm) larger than the bolt diameter and a slot length
not to exceed 1-3/4 inches (44 mm), provided a standard cut
washer is placed between the plate washer and the nut.
R602.11.2 Interior braced wall panel connections. Interior
braced wall panels shall be fastened to floor and roof framing
in accordance with Table R602.3(1), to foundations in
accordance with Section R602.11.1, and in accordance with the
following requirements:
1. Floor joists parallel to the top plate shall be toe-nailed to the top plate with at least 8d nails spaced a maximum of 6 inches (152 mm) on center.
2. Top plate laps shall be face-nailed with at least eight 16d nails on each side of the splice.
R602.11.3 Stepped foundations. Where stepped foundations
occur, the following requirements apply:
1. Where the height of a required braced wall panel that extends from foundation to floor above varies more than 4 feet (1220 mm), the braced wall panel shall be constructed in accordance with Figure R602.11.3.
2. Where the lowest floor framing rests directly on a sill plate anchored to a foundation not less than 8 feet (2440 mm) in length along a line of bracing, the line shall be considered as braced. The double plate of the cripple wall beyond the segment of footing that extends to the lowest framed floor shall be spliced by extending the upper top plate a minimum of 4 feet (1219 mm) along the foundation. Anchor bolts shall be located a maximum of 1 foot and a minimum of seven bolt diameters (305 and 914 mm) from each end of the plate section at the step in the foundation.
3. Where cripple walls occur between the top of the foundation and the lowest floor framing, the bracing requirements for a story shall apply.
4. Where only the bottom of the foundation is stepped and the lowest floor framing rests directly on a sill plate anchored to the foundations, the requirements of Section R602.11.1 shall apply.
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OPTION 2SECTIONS R602.3; R602.10; R602.11
NEW SECTION
WAC 51-51-0602
Section R602 -- Wood wall framing.
R602.3 Design and construction. Exterior walls of wood
light-framed construction shall be designed and constructed in
accordance with the provisions of this chapter and Figures
R602.3(1) and R602.3(2) or in accordance with AF&PA's NDS.
Components of exterior walls shall be fastened in accordance
with Table R602.3(1) through R602.3(4). Exterior walls
covered with foam plastic sheathing shall be braced in
accordance with Section R602.10. Structural sheathing shall
be fastened directly to structural framing members.
R602.3.4 Bottom (sole) plate. Studs shall have full bearing
on a 2-inch nominal (38 mm) or larger bottom (sole) plate or
sill plate having a width at least equal to the width of the
studs.
R602.10 Wall bracing. Buildings shall be braced in accordance
with Sections R602.10 through R602.10.8. All exterior walls
shall be braced. Bracing shall be provided at interior walls
spaced in accordance with Section R602.10.1.1. Bracing shall
consist of braced wall lines in accordance with Section
R602.10.1. For buildings in Seismic Design Categories D0, D1
and D2, walls shall be constructed in accordance with the
additional requirements of Sections R602.10.11 through
R602.11.3.
R602.10.1 Braced wall lines. Braced wall lines shall consist
of braced wall panels constructed in accordance with Section
R602.10.3. The locations and percentages of bracing shall be
in accordance with Table R602.10.1 and shall be the greater of
that required by the Seismic Design Category and the design
wind speed. Braced wall panels shall begin no more than 12.5
feet (3810 mm) from each end of a braced wall line. Braced
wall panels in a braced wall line shall be in line.
| EXCEPTION: | In a braced wall line, out-of-plane offsets of braced wall panels shall be permitted provided they comply with the following: |
| 1. The offsets between adjacent braced wall panels do not exceed 4 feet (1219 mm) in width; and | |
| 2. The aggregate width of out-of-plane offsets at all the braced wall panels does not exceed 8 feet (2438 mm). |
| EXCEPTIONS: | 1. Spacing of braced wall lines not exceeding 50 feet (15.24 m) shall be permitted where: |
| 1.1. The wall bracing installed equals or exceeds the percentages of bracing specified in Table R602.10.1 multiplied by a factor equal to the braced wall line spacing divided by 35 feet (10.67 m); and | |
| 1.2. The length-to-width ratio of the floor or roof diaphragm does not exceed 3:1. | |
| 2. Spacing of braced wall lines at buildings in Seismic Design Categories D0, D1 and D2 shall comply with Section R602.10.11.1. |
R602.10.2.1 Seismic Design Categories Other than D2. In
Seismic Design Categories other than D2, cripple walls
supporting exterior walls or interior braced wall panels as
required in Section R403.1.2 and R403.1.2.1 shall be braced
with an amount and type of bracing as required for the wall
above in accordance with Table R602.10.1 with the following
modifications for cripple wall bracing:
1. The percent bracing amount as determined from Table R602.10.1 shall be increased by 15 percent; and
2. The wall panel spacing shall be decreased to 18 feet (5486 mm) instead of 25 feet (7620 mm).
R602.10.2.2 Seismic Design Category D2. In Seismic Design
Category D2, cripple walls supporting exterior walls or
interior braced wall panels as required in Section R403.1.2
and R403.1.2.1 shall be braced in accordance with Table
R602.10.1.
R602.10.2.3 Redesignation of cripple walls. In any Seismic
Design Category, cripple walls are permitted to be
redesignated as the first story walls for purposes of
determining wall bracing requirements. If the cripple walls
are redesignated, the stories above the redesignated story
shall be counted as the second and third stories,
respectively.
R602.10.5 Continuous wood structural panel sheathing. When
continuous wood structural panel sheathing is provided in
accordance with Method 3 of Section R602.10.3 on all
sheathable areas of all exterior walls including areas above
and below openings, braced wall panel lengths are not required
to be in accordance with Section R602.10.4 provided they are
in accordance with Table R602.10.5. Wood structural panel
sheathing shall be installed at corners in accordance with
Figure R602.10.5. The bracing percentages in Table R602.10.1
for Method 3 shall be permitted to be multiplied by a factor
of 0.9 for exterior walls with a maximum opening height that
does not exceed 85 percent of the wall height or a factor of
0.8 for exterior walls with a maximum opening height that does
not exceed 67 percent of the wall height.
LENGTH REQUIREMENTS FOR BRACED WALL PANELS IN A CONTINUOUSLY SHEATHED WALLa,b
a. Linear interpolation shall be permitted.
b. Full-height sheathed wall segments on either side of garage openings that support roofs of light-framed construction only, with roof covering dead loads of 3 psf or less shall be permitted to have a 4:1 height-to-width ratio.
c. Walls on either or both sides of openings in garages attached to fully sheathed dwellings shall be permitted to be built in accordance with Section R602.10.6.2 and Figure R602.10.6.2 except that a single sill plate shall be permitted and two anchor bolts shall be placed at 1/3 points. In addition, tie-down devices shall not be required and the vertical wall segment shall have a maximum 6:1 height-to-width ratio (with height being measured from top of header to the bottom of the sill plate). This option shall be permitted for the first story of two-story applications in Seismic Design Categories A through C.
R602.10.6 Alternate braced wall panel construction methods.
Alternate braced wall panels shall be constructed in
accordance with Sections R602.10.6.1 and R602.10.6.2.
R602.10.6.1 Alternate braced wall panels. Alternate braced
wall lines constructed in accordance with one of the following
provisions shall be permitted to replace each 4 feet (1219 mm)
of braced wall panel as required by Section R602.10.4. The
maximum height and minimum width of each panel shall be in
accordance with Table R602.10.6.
1. In one-story buildings, each panel shall be sheathed on one face with 3/8-inch-minimum-thickness (9.5 mm) wood structural panel sheathing nailed with 8d common or galvanized box nails in accordance with Table R602.3(1) and blocked at all wood structural panel sheathing edges. Two anchor bolts installed in accordance with Figure R403.1(1) shall be provided in each panel. Anchor bolts shall be placed in from each end of the panel a horizontal distance of one-fourth the panel width. Each panel end stud shall have a tie-down device fastened to the foundation, capable of providing an uplift capacity in accordance with Table R602.10.6. The tie-down device shall be installed in accordance with the manufacturer's recommendations. The panels shall be supported directly on a foundation or on floor framing supported directly on a foundation, which is continuous across the entire length of the braced wall line. This foundation shall be reinforced with not less than one No. 4 bar top and bottom. When the continuous foundation is required to have a depth greater than 12 inches (305 mm), a minimum 12-inch by 12-inch (305 mm by 305 mm) continuous footing or turned down footing is permitted at door openings in the braced wall line. This continuous footing or turned down footing shall be reinforced with not less than one No. 4 bar top and bottom. This reinforcement shall be lapped 15 inches (381 mm) with the reinforcement required in the continuous foundation located directly under the braced wall line.
2. In the first story of two-story buildings, each braced wall panel shall be in accordance with Item 1 above, except that the following:
2.1 The wood structural panel sheathing shall be provided on both faces;
2.2 Sheathing edge nailing spacing shall not exceed 4 inches on center; and
2.3 Anchor bolts shall be placed at the center of the panel width and in from each end of the panel a horizontal distance of one-fifth the panel width (three total).
R602.10.6.2 Alternate braced wall panel adjacent to a door or
window opening. Alternate braced wall panels constructed in
accordance with one of the following provisions are also
permitted to replace each 4 feet (1219 mm) of braced wall
panel as required by Section R602.10.4 for use adjacent to a
window or door opening with a full-length header:
1. In one-story buildings, each panel shall have a length of not less than 16 inches (406 mm) and a height of not more than 10 feet (3048 mm). Each panel shall be sheathed on one face with a single layer of 3/8-inch-minimum-thickness (9.5 mm) wood structural panel sheathing nailed with 8d common or galvanized box nails in accordance with Figure R602.10.6.2. The wood structural panel sheathing shall extend up over the solid sawn or glued-laminated header and shall be nailed in accordance with Figure R602.10.6.2. Use of a built-up header consisting of at least two 2 x 12s and fastened in accordance with Table R602.3(1) shall be permitted. A spacer, if used, shall be placed on the side of the built-up beam opposite the wood structural panel sheathing. The header shall extend between the inside faces of the first full-length outer studs of each panel. The clear span of the header between the inner studs of each panel shall be not less than 6 feet (1829 mm) and not more than 18 feet (5486 mm) in length. A strap with an uplift capacity of not less than 1,000 pounds (4448 N) shall fasten the header to the side of the inner studs opposite the sheathing. One anchor bolt not less than 5/8-inch-diameter (16 mm) and installed in accordance with Section R403.1.6 shall be provided in the center of each sill plate. The studs at each end of the panel shall have a tie-down device fastened to the foundation with an uplift capacity of not less than 4,200 pounds (18 683 N).
Where a panel is located on one side of the opening, the header shall extend between the inside face of the first full-length stud of the panel and the bearing studs at the other end of the opening. A strap with an uplift capacity of not less than 1,000 pounds (4448 N) shall fasten the header to the bearing studs. The bearing studs shall also have a tie-down device fastened to the foundation with an uplift capacity of not less than 1,000 pounds (4448 N).
The tie-down devices shall be an embedded strap type, installed in accordance with the manufacturer's recommendations. The panels shall be supported directly on a foundation, which is continuous across the entire length of the braced wall line. This foundation shall be reinforced with not less than one No. 4 bar top and bottom.
Where the continuous foundation is required to have a depth greater than 12 inches (305 mm), a minimum 12-inch by 12-inch (305 mm by 305 mm) continuous footing or turned down footing is permitted at door openings in the braced wall line. This continuous footing or turned down footing shall be reinforced with not less than one No. 4 bar top and bottom. This reinforcement shall be lapped not less than 15 inches (381 mm) with the reinforcement required in the continuous foundation located directly under the braced wall line.
2. In the first story of two-story buildings, each wall panel shall be braced in accordance with Item 1 above, except that each panel shall have a length of not less than 24 inches (610 mm).
R602.10.7 Panel joints. All vertical joints of panel
sheathing shall occur over and be fastened to common studs.
Horizontal joints in braced wall panels shall occur over and
be fastened to common blocking of a minimum 2 inches in
nominal thickness.
| EXCEPTION: | Blocking is not required behind horizontal joints in Seismic Design Categories A and B and detached dwellings in Seismic Design Category C when constructed in accordance with Section R602.10.3, braced-wall-panel construction Method 3 and Table R602.10.1, Method 3, or where permitted by the manufacturer's installation requirements for the specific sheathing material. |
R602.10.9 Interior braced wall support. This section is not
adopted. See Section R403.1.2.
R602.10.10 Design of structural elements. Where a building,
or portion thereof, does not comply with one or more of the
bracing requirements in Sections R602.10 through R602.10.9,
those portions shall be designed and constructed in accordance
with accepted engineering practice.
R602.10.11 Bracing in Seismic Design Categories D0, D1 and D2.
Structures located in Seismic Design Categories D0, D1 and D2
shall have exterior and interior braced wall lines in
accordance with Sections R602.10.11.1 through R602.10.11.5.
R602.10.11.1 Braced wall line spacing. Spacing between braced
wall lines in each story shall not exceed 25 feet (7620 mm) on
center in both the longitudinal and transverse directions.
| EXCEPTION: | In one- and two-story buildings two adjacent braced wall lines shall not exceed 35 feet (10,363 mm) on center in order to accommodate an area not exceeding 900 square feet (84 m2) in each floor of the dwelling unit. Spacing between all other braced wall lines shall not exceed 25 feet (7620 mm). |
| EXCEPTION: | For braced wall panel construction Method 3 of Section R602.10.3, the exterior braced wall panel shall be permitted to begin no more than 8 feet (2438 mm) from each end of the braced wall line provided one of the following conditions is met: |
| 1. A minimum 24-inch-wide (610 mm) panel is applied to each side of the building corner and the two 24-inch-wide (610 mm) panels at the corner shall be attached to framing in accordance with Figure R602.10.5. | |
| 2. The end of each braced wall panel closest to the corner shall have a tie-down device fastened to the stud at the edge of the braced wall panel closest to the corner and to the foundation or framing below. The tie-down device shall be capable of providing an uplift allowable design value of at least 1,800 pounds (8 kN). The tie-down device shall be installed in accordance with the manufacturer's recommendations. |
R602.10.11.4 Cripple wall bracing. In addition to the
requirements of Section R602.10.2, where interior braced wall
panels occur without a foundation below, the length of
parallel exterior cripple wall bracing shall be one and
one-half times the length required by Table R602.10.1. Where
cripple walls braced using Method 3 of Section R602.10.3
cannot provide this additional length, the capacity of the
sheathing shall be increased by reducing the spacing of
fasteners along the perimeter of each piece of sheathing to 4
inches (102 mm) on center.
R602.10.11.5 Sheathing attachment. Adhesive attachment of
wall sheathing shall not be permitted in Seismic Design
Categories C, D0, D1 and D2.
R602.11 Framing and connections for Seismic Design Categories
D0, D1 and D2. The framing and connection details of buildings
located in Seismic Design Categories D0, D1 and D2 shall be in
accordance with Sections R602.11.1 through R602.11.3.
R602.11.1 Wall anchorage. Braced wall line sill plates shall
be anchored to concrete or masonry foundations in accordance
with Sections R403.1.6 and R602.11. For all buildings in
Seismic Design Categories D0, D1 and D2 and townhouses in
Seismic Design Category C, plate washers, a minimum of 0.229
inch by 3 inches by 3 inches (5.8 mm by 76 mm by 76 mm) in
size, shall be installed between the foundation sill plate and
the nut. The hole in the plate washer is permitted to be
diagonally slotted with a width of up to 3/16 inch (5 mm)
larger than the bolt diameter and a slot length not to exceed
1-3/4 inches (44 mm), provided a standard cut washer is placed
between the plate washer and the nut.
R602.11.2 Interior braced wall panel connections. Interior
braced wall panels shall be fastened to floor and roof framing
in accordance with Table R602.3(1), to required foundations in
accordance with Section R602.11.1, and in accordance with the
following requirements:
1. Floor joists parallel to the top plate shall be toe-nailed to the top plate with at least 8d nails spaced a maximum of 6 inches (152 mm) on center.
2. Top plate laps shall be face-nailed with at least eight 16d nails on each side of the splice.
R602.11.3 Stepped foundations. Where stepped foundations
occur, the following requirements apply:
1. Where the height of a required braced wall panel that extends from foundation to floor above varies more than 4 feet (1220 mm), the braced wall panel shall be constructed in accordance with Figure R602.11.3.
2. Where the lowest floor framing rests directly on a sill plate anchored to a foundation not less than 8 feet (2440 mm) in length along a line of bracing, the line shall be considered as braced. The double plate of the cripple wall beyond the segment of footing that extends to the lowest framed floor shall be spliced by extending the upper top plate a minimum of 4 feet (1219 mm) along the foundation. Anchor bolts shall be located a maximum of 1 foot and a minimum of seven bolt diameters (305 and 914 mm) from each end of the plate section at the step in the foundation.
3. Where cripple walls occur between the top of the foundation and the lowest floor framing, the bracing requirements for a story shall apply.
4. Where only the bottom of the foundation is stepped and the lowest floor framing rests directly on a sill plate anchored to the foundations, the requirements of Section R602.11.1 shall apply.
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R613.4 Testing and labeling. Exterior windows and sliding
doors shall be tested by an approved independent laboratory,
and bear a label identifying manufacturer, performance
characteristics and approved inspection agency to indicated
compliance with AAMA/WDMA/CSA 101/I.S.2/A440. Exterior
side-hinged doors shall be tested and labeled as conforming to
AAMA/WDMA/CSA 101/I.S.2/A440 or comply with Section R613.6.
| EXCEPTION: | 1. Decorative glazed openings. |
| 2. Custom exterior windows and doors manufactured by a small business shall be exempt from all testing requirements in Section R-613 of the International Residential Code provided they meet the applicable provisions of Chapter 24 of the International Building Code. |
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R703.1 General. Exterior walls shall provide the building
with a weather-resistant exterior wall envelope. The exterior
wall envelope shall include flashing as described in Section
R703.8. The exterior wall envelope shall be designed and
constructed in a manner that prevents the accumulation of
water within the wall assembly by providing a water-resistant
barrier behind the exterior veneer as required by Section
R703.2 and a means of draining water that enters the assembly
to the exterior. Protection against condensation in the
exterior wall assembly shall be provided in accordance with
the Washington State Energy Code (chapter 51-11 WAC).
| EXCEPTION: | 1. A weather-resistant exterior wall envelope shall not be required over concrete or masonry walls designed in accordance with Chapter 6 and flashed according to Section R703.7 or R703.8. |
| 2. Compliance with the requirements for a means of drainage, and the requirements of Section R703.2 and R703.8, shall not be required for an exterior wall envelope that has been demonstrated to resist wind-driven rain through testing of the exterior wall envelope, including joints, penetrations and intersections with dissimilar materials, in accordance with ASTM E 331 under the following conditions: | |
| 2.1 Exterior wall envelope test assemblies shall include at least one opening, one control joint, one wall/eave interface and one wall sill. All tested openings and penetrations shall be representative of the intended end-use configuration. | |
| 2.2 Exterior wall envelope test assemblies shall be at least 4 feet (1219 mm) by 8 feet (2438 mm) in size. | |
| 2.3 Exterior wall assemblies shall be tested at a minimum differential pressure of 6.24 pounds per square foot (299 Pa). | |
| 2.4 Exterior wall envelope assemblies shall be subjected to a minimum test exposure duration of 2 hours. | |
| The exterior wall envelope design shall be considered to resist wind-driven rain where the results of testing indicate that water did not penetrate: Control joints in the exterior wall envelope; joints at the perimeter of openings penetration; or intersections of terminations with dissimilar materials. |
| EXCEPTION: | Omission of the water-resistive barrier is permitted in the following situations: |
| 1. In detached accessory buildings. | |
| 2. Under exterior wall finish materials as permitted in Table R703.4. | |
| 3. Under paperbacked stucco lath when the paper backing is an approved weather-resistive sheathing paper. |
1. Exterior window and door openings. Flashing at exterior window and door openings shall extend to the surface of the exterior wall finish or to the water-resistive barrier for subsequent drainage.
2. At the intersection of chimneys or other masonry construction with frame or stucco walls, with projecting lips on both sides under stucco copings.
3. Under and at the ends of masonry, wood or metal copings or sills.
4. Continuously above all projecting wood trim.
5. Where exterior porches, decks or stairs attach to a wall or floor assembly or wood-frame construction.
6. At wall and roof intersections.
7. At built-in gutters.
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R806.4 Conditioned attic assemblies. This section is not
adopted.
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M1201.1 Scope. The provisions of Chapters 12 through 24 shall
regulate the design, installation, maintenance, alteration and
inspection of mechanical systems that are permanently
installed and utilized to provide control of environmental
conditions within buildings. These chapters shall also
regulate those mechanical systems, system components,
equipment and appliances specifically addressed in this code.
| EXCEPTION: | The standards for liquefied petroleum gas installations shall be the 2004 Edition of NFPA 58 (Liquefied Petroleum Gas Code) and the 2006 Edition of ANSI Z223.1/NFPA 54 (National Fuel Gas Code). |
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STANDARD TEST METHOD FOR PARTICULATE EMISSIONS FROM FIREPLACES
See Section R1004.1, International Residential Code
Standard is located in International Building Code, Chapter 35
[Statutory Authority: RCW 19.27.031 and 19.27.074. 04-01-109, § 51-51-4300, filed 12/17/03, effective 7/1/04.]
AF101.1 General. This appendix contains requirements for new
construction in jurisdictions where radon-resistant
construction is required.
Inclusion of this appendix by jurisdictions shall be required in high radon potential counties as determined in Figure AF101 and as listed in Table AF101(1).
Unvented crawl spaces are not permitted in any high radon
potential county. In other areas, requirements of this
appendix apply to any structure constructed with unvented
crawl spaces as specified in R408.3.
|
a. EPA recommends that this county listing be supplemented with other available state and local data to further understand the radon potential of Zone 1 areas.
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AF103.1 General. The following construction techniques are
intended to resist radon entry and prepare the building for
post-construction radon mitigation, if necessary (see Figure
AF102). These techniques are required in high radon potential
counties designated in Table AF101(1).
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The following sections of the Washington Administrative Code are repealed:
| WAC 51-51-0101 | Section R101 -- Title, scope and purpose. |
| WAC 51-51-0324 | Section R324 -- Adult family homes. |
| WAC 51-51-2401 | Section G2401 (101) -- General. |
| WAC 51-51-2415 | Section G2415 (404) -- Piping system installation. |