WSR 10-16-095

PROPOSED RULES

BUILDING CODE COUNCIL


[ Filed July 30, 2010, 2:43 p.m. ]

Original Notice.

Exempt from preproposal statement of inquiry under RCW 34.05.310(4).

Title of Rule and Other Identifying Information: Amendment of chapter 51-51 WAC, Washington State Residential Code.

Hearing Location(s): Spokane City Council Chambers, West 808 Spokane Falls Boulevard, Spokane, WA, on September 10, 2010, at 10:00 a.m.; and at Senate Hearing Room 2, Cherberg Building, Washington State Capitol Campus, Olympia, Washington, on September 24, 2010, at 10:00 a.m.

Date of Intended Adoption: October 15, 2010.

Submit Written Comments to: John Cochran, Council Chair, P.O. Box 41014, Olympia, WA 98504-1014, e-mail joanne.mccaughan@ga.wa.gov, fax (360) 586-9383, by September 24, 2010.

Assistance for Persons with Disabilities: Contact Peggy Bryden by August 26, 2010, TTY (360) 753-7427 or (360) 725-2966.

Purpose of the Proposal and Its Anticipated Effects, Including Any Changes in Existing Rules: Chapter 51-51 WAC, Washington State Residential Code.

Section 403.1: Will change table references from stories to floors.

Section R403.4: Will correct reference to figure.

Section R404.1: Will correct title of Table.

Section R404.1.2.2: Will remove lateral support requirement on bottom of foundation walls.

Section R404.4: Will allow 48" fill for retaining walls.

Reasons Supporting Proposal: Clarifies and corrects code for consistent enforcement.

Statutory Authority for Adoption: RCW 19.27.074.

Statute Being Implemented: Chapter 19.27 RCW.

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

Name of Proponent: State building code council, governmental.

Name of Agency Personnel Responsible for Drafting and Implementation: Joanne McCaughan, P.O. Box 41014, Olympia, WA 98504-1014, (360) 725-2970; and Enforcement: Local jurisdictions.

No small business economic impact statement has been prepared under chapter 19.85 RCW. The changes will clarify existing rules and will have no disproportionate impact on small businesses.

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.

July 26, 2010

John C. Cochran

Council Chair

OTS-3501.2


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

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 which shall be 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 engineered fill. Foundation walls complying with Section R404 or stem walls complying with Section R403.1.3 shall be permitted to support exterior walls, exterior braced wall lines and exterior braced wall panels provided they are supported by continuous footings.



TABLE R403.1

MINIMUM WIDTH OF CONCRETE,

PRECAST OR MASONRY FOOTINGS

(inches)



LOAD-BEARING VALUE OF SOIL (psf)
1,500 2,000 3,000 ≥4,000
Conventional light-frame construction
1 floorb,c 12 12 12 12
2 floorsb,c 15 12 12 12
3 floorsb,c 23 17 12 12
4-inch brick veneer over light frame or 8-inch hollow concrete masonry
1-story 12 12 12 12
2-story 21 16 12 12
3-story 32 24 16 12
8-inch solid or fully grouted masonry
1-story 16 12 12 12
2-story 29 21 14 12
3-story 42 32 21 16

For SI: 1 inch = 25.4 mm, 1 pound per square foot = 0.0479kPa.
a. Where minimum footing width is 12 inches, use of a single wythe of solid or fully grouted 12-inch nominal concrete masonry units is permitted.
b. Represents the number of floors supported.
c. Footings shall be permitted to support a roof in addition to the stipulated number of floors. Footings supporting a roof only shall be as required for supporting one floor.

R403.1.2 Continuous Footing in Seismic Design Categories D0, D1 and D2. The braced wall panels at exterior walls of buildings located in Seismic Design Categories D0, D1 and D2 shall be supported by continuous footings. All required interior braced wall panels shall be supported on footings at intervals not exceeding 50 feet (15,240 mm).


Figure 403.4(1). Note corrected title and labels:

BASEMENT OR CRAWL SPACE WITH PRECAST CONCRETE FOUNDATION WALL BEARING ON CRUSHED STONE

PRECAST CONCRETE FOUNDATION WALL

CRUSHED STONE FOOTING


Figure 403.4(2). Note corrected title and label:

BASEMENT OR CRAWL SPACE WITH PRECAST CONCRETE FOUNDATION WALL ON SPREAD FOOTING

PRECAST CONCRETE FOUNDATION WALL

[Statutory Authority: RCW 19.27.031 and 19.27.074. 10-03-098, 51-51-0403, filed 1/20/10, effective 7/1/10. Statutory Authority: RCW 19.27.190, 19.27.020, and chapters 19.27 and 34.05 RCW. 08-01-103, 51-51-0403, filed 12/18/07, effective 4/1/08. Statutory Authority: RCW 19.27.074, 19.27.020, and chapters 19.27 and 34.05 RCW. 07-01-090, 51-51-0403, filed 12/19/06, effective 7/1/07.]


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

WAC 51-51-0404   ((Reserved.)) Section R404 -- Foundation and retaining walls.  


Table R404.1.1(3). Note corrected title:

10-INCH MASONRY FOUNDATION WALLS WITH REINFORCING WHERE d > 6.75 INCHESa,c


R404.1.2.2 Reinforcement for foundation walls. Concrete foundation walls shall be laterally supported at the top except where permitted in R404.1.2.2.1 and R404.1.2.2.2, and at the bottom where required elsewhere in this code. Horizontal reinforcement shall be provided in accordance with Table R404.1.2(1). Vertical reinforcement shall be provided in accordance with Table R404.1.2(2), R404.1.2(3), R404.1.2(4), R404.1.2(5), R404.1.2(6), R404.1.2(7) or R404.1.2(8). Vertical reinforcement for flat basement walls retaining 4 feet (1,219 mm) or more of unbalanced backfill is permitted to be determined in accordance with Table R404.1.2(9).


For basement walls supporting above-grade concrete walls, vertical reinforcement shall be the greater of that required by Tables R404.1.2(2) through R404.1.2(8) or by Section 611.6 for the above-grade wall. In buildings assigned to Seismic Design Category D0, D1 or D2, concrete foundation walls shall also comply with Section R404.1.4.2.


R404.4 Retaining Walls. Retaining walls not supporting a structure that are not laterally supported at the top and that retain in excess of 24 inches (610 mm) of unbalanced fill shall be designed to ensure stability against overturning, sliding, excessive foundation pressure and water uplift. Retaining walls shall be designed for a safety factor of 1.5 against lateral sliding and overturning.

[Statutory Authority: RCW 19.27.031 and 19.27.074. 10-03-098, 51-51-0404, filed 1/20/10, effective 7/1/10. Statutory Authority: RCW 19.27.190, 19.27.020, and chapters 19.27 and 34.05 RCW. 08-01-102, 51-51-0404, filed 12/18/07, effective 4/1/08. Statutory Authority: RCW 19.27.074, 19.27.020, and chapters 19.27 and 34.05 RCW. 07-01-090, 51-51-0404, filed 12/19/06, effective 7/1/07.]

Washington State Code Reviser's Office