Fort
Silver Member
In CA, 2010 CRC.
Townhomes, at the common-wall, where extends up thru attic to bottom of roof sheathing.
The code is silent on whether penetrations are permitted in the fire retardant roof sheathing 5/8" type x gyp. when using that exception. (see below).
Questions:
1). Is a continuous attic vent permitted within this 4'-0" zone near the common wall ? Is your answer based on code section reference, or judgement of AHJ?
2). Are other types of penetrations permitted, such as plumbing or hvac ? Is your answer based on code section reference, or judgement of AHJ?
Code Citation:
R302.2.2 Parapets. Parapets constructed in accordance with Section R302.2.3 shall be constructed for townhouses as an extension of exterior walls or common walls in accordance with the following:
Where roof surfaces adjacent to the wall or walls are at the same elevation, the parapet shall extend not less than 30 inches (762 mm) above the roof surfaces.
Where roof surfaces adjacent to the wall or walls are at different elevations and the higher roof is not more than 30 inches (762 mm) above the lower roof, the 68 parapet shall extend not less than 30 inches (762 mm) above the lower roof surface.
Exception: A parapet is not required in the two cases above when the roof is covered with a minimum class C roof covering, and the roof decking or sheathing is of noncombustible materials or approved fire-retardant-treated wood for a distance of 4 feet (1219 mm) on each side of the wall or walls, or one layer of 5/8-inch (15.9 mm) Type X gypsum board is installed directly beneath the roof decking or sheathing, supported by a minimum of nominal 2-inch (51 mm) ledgers attached to the sides of the roof framing members, for a minimum distance of 4 feet (1219 mm) on each side of the wall or walls.
Townhomes, at the common-wall, where extends up thru attic to bottom of roof sheathing.
The code is silent on whether penetrations are permitted in the fire retardant roof sheathing 5/8" type x gyp. when using that exception. (see below).
Questions:
1). Is a continuous attic vent permitted within this 4'-0" zone near the common wall ? Is your answer based on code section reference, or judgement of AHJ?
2). Are other types of penetrations permitted, such as plumbing or hvac ? Is your answer based on code section reference, or judgement of AHJ?
Code Citation:
R302.2.2 Parapets. Parapets constructed in accordance with Section R302.2.3 shall be constructed for townhouses as an extension of exterior walls or common walls in accordance with the following:
Where roof surfaces adjacent to the wall or walls are at the same elevation, the parapet shall extend not less than 30 inches (762 mm) above the roof surfaces.
Where roof surfaces adjacent to the wall or walls are at different elevations and the higher roof is not more than 30 inches (762 mm) above the lower roof, the 68 parapet shall extend not less than 30 inches (762 mm) above the lower roof surface.
Exception: A parapet is not required in the two cases above when the roof is covered with a minimum class C roof covering, and the roof decking or sheathing is of noncombustible materials or approved fire-retardant-treated wood for a distance of 4 feet (1219 mm) on each side of the wall or walls, or one layer of 5/8-inch (15.9 mm) Type X gypsum board is installed directly beneath the roof decking or sheathing, supported by a minimum of nominal 2-inch (51 mm) ledgers attached to the sides of the roof framing members, for a minimum distance of 4 feet (1219 mm) on each side of the wall or walls.