WSR 14-24-088

PERMANENT RULES

BUILDING CODE COUNCIL

[Filed December 1, 2014, 4:00 p.m., effective May 1, 2015]

Effective Date of Rule: May 1, 2015.

Purpose: Make changes to chapter 51-51 WAC to modify requirements in the Washington State Residential Code related to fire separation requirements for townhouse construction. Requirements have been previously changed through emergency rule making.

Citation of Existing Rules Affected by this Order: Amending WAC 51-51-0302.

Statutory Authority for Adoption: RCW 19.27.074.

Other Authority: RCW 19.27.020, 19.27.031.

Adopted under notice filed as WSR 14-16-031 on July 28, 2014.

Number of Sections Adopted in Order to Comply with Federal Statute: New 0, Amended 0, Repealed 0; Federal Rules or Standards: New 0, Amended 0, Repealed 0; or Recently Enacted State Statutes: New 0, Amended 0, Repealed 0.

Number of Sections Adopted at Request of a Nongovernmental Entity: New 0, Amended 1, Repealed 0.

Number of Sections Adopted on the Agency's Own Initiative: New 0, Amended 0, Repealed 0.

Number of Sections Adopted in Order to Clarify, Streamline, or Reform Agency Procedures: New 0, Amended 0, Repealed 0.

Number of Sections Adopted Using Negotiated Rule Making: New 0, Amended 0, Repealed 0; Pilot Rule Making: New 0, Amended 0, Repealed 0; or Other Alternative Rule Making: New 0, Amended 0, Repealed 0.

Date Adopted: November 14, 2014.

C. Ray Allshouse

Council Chair

AMENDATORY SECTION (Amending WSR 13-23-084, filed 11/19/13, effective 4/1/14)

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

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


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

TABLE R302.1(1)

EXTERIOR WALLS


Exterior Wall Element		Minimum Fire-Resistance Rating	Minimum Fire Separation Distance
Walls	Fire-resistance rated	1-hour tested in accordance with ASTM E 119 or UL 263 with exposure from both sides	< 5 feet
	Not fire-resistance rated	0 hours	≥ 5 feet
Projections	Fire-resistance rated	1 hour on the undersidea, b	≥ 2 feet to < 5 feet
	Not fire-resistance rated	0 hours	≥ 5 feet
Openings in walls	Not allowed	N/A	< 3 feet
	25% maximum of wall area per story	0 hours	3 feet
	Unlimited	0 hours	5 feet
Penetrations	All	Comply with Section R302.4	< 5 feet
		None required	5 feet


For IS: 1 foot = 304.8 mm. N/A = Not Applicable
a Roof eave fire-resistance rating shall be permitted to be reduced to 0 hours on the underside of the eave if fire blocking is provided from the wall top plate to the underside of the roof sheathing.
b Roof eave fire-resistance rating shall be permitted to be reduced to 0 hours on the underside of the eave provided no gable vent openings are installed.

Table R302.1(2)

Exterior Walls—Dwellings with Fire Sprinklers


Exterior Wall Element		Minimum Fire-Resistance Rating	Minimum Fire Separation Distance
Walls	Fire-resistance rated	1-hour tested in accordance with ASTM E 119 or UL 263 with exposure from the outside	0 feet
	Not fire-resistance rated	0 hours	3 feeta
Projections	Fire-resistance rated	1 hour on the undersideb, c	2 feeta
	Not fire-resistance rated	0 hours	3 feet
Openings in walls	Not allowed	N/A	< 3 feet
	Unlimited	0 hours	3 feeta
Penetrations	All	Comply with Section R302.4	< 3 feet
		None required	3 feeta


For IS: 1 foot = 304.8 mm. N/A = Not Applicable
a For residential subdivisions where all dwellings are equipped throughout with an automatic sprinkler system installed in accordance with P2904, the fire separation distance for nonrated exterior walls and 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 Roof eave fire-resistance rating shall be permitted to be reduced to 0 hours on the underside of the eave if fire blocking is provided from the wall top plate to the underside of the roof sheathing.
c Roof eave fire-resistance rating shall be permitted to be reduced to 0 hours on the underside of the eave provided no gable vent openings are installed.

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 exterior walls 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 exterior walls 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.

R302.2.1 Continuity. The fire-resistance-rated wall or assembly separating townhouses 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; or

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

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. Townhouses separated by a common ((1-hour fire-resistance-rated)) wall as provided in Section R302.2, Item 1 or 2.
	6. Floor sheathing may fasten to the floor framing of both units.

R302.3.1 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:
	1. Automatic fire sprinklers are installed in accordance with appendix R in both dwelling units;
	or
	2. All required smoke alarms in both dwelling units are interconnected in such a manner that the actuation of one alarm will activate all alarms in both dwelling units.