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.

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

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 undersideab	> 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	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.

R302.2 Townhouses. Each townhouse shall be considered a separate building and shall be separated by fire-resistance-rated wall assemblies meeting the requirements of Section R302.1 for exterior walls.

EXCEPTION:

(1) A common 1-hour fire-resistance rated wall assembly tested in accordance with ASTM E 119 or UL 263 is permitted for townhouses where an automatic sprinkler system is installed in accordance with NFPA 13 D, if such walls do not contain plumbing or mechanical equipment, ducts or vents in the cavity of the common wall. The wall shall be rated for fire exposure from both sides and shall extend to and be tight against exterior walls and the underside of the roof sheathing. Electrical installations shall be installed in accordance with chapter 296-46B WAC or electrical code as adopted by the local jurisdiction. 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 is permitted for townhouses if such walls do not contain plumbing or mechanical equipment, ducts or vents in the cavity of the common wall. The wall shall be rated for fire exposure from both sides and shall extend to and be tight against exterior walls and the underside of the roof sheathing. Electrical installations shall be installed in accordance with chapter 296-46B WAC or electrical code as adopted by the local jurisdiction. Penetrations of electrical outlet boxes shall be in accordance with Section R302.4.

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 2-hour fire-resistance-rated wall as provided in Section R302.2.
	6. Floor sheathing may fasten to the floor framing of both units.

[Statutory Authority: RCW 19.27.031 and 19.27.074. 10-03-098, § 51-51-0302, 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. 09-04-023, § 51-51-0302, filed 1/27/09, effective 7/1/09; 08-01-102, § 51-51-0302, filed 12/18/07, effective 4/1/08.]