NYC Building Code 2008: Fire Wall Continuity

705.6 Vertical continuity. Fire walls shall extend from the foundation through the roof, to form a parapet at least 30 inches (762 mm) in height. Such parapet shall in no event extend to a point less than 4 inches (102 mm) above the highest point of peaked or gabled roof.

Exceptions:

1. Where a 2-hour fire wall is permitted in accordance with Table 705.4, such wall shall be permitted to terminate at the underside of the roof sheathing, deck or slab provided:

1.1. The lower roof assembly within 4 feet (1219 mm) of the wall has not less than a 1-hour fire-resistance rating and the entire length and span of supporting elements for the rated roof assembly has a fire-resistance rating of not less than 1 hour; and

1.2. Openings in the roof shall not be located within 4 feet (1219 mm) of the fire wall; and

1.3. Each building shall be provided with not less than a Class A roof covering.

2. In buildings of Type I or II construction, fire walls shall be permitted to terminate at the underside of noncombustible roof sheathing, deck, or slabs where both buildings are provided with not less than a Class A roof covering. Openings in the roof shall not be located within 4 feet (1219 mm) of the fire wall.

3. In buildings of Type III, IV and V construction, fire walls shall be permitted to terminate at the underside of noncombustible roof sheathing or decks provided:

3.1. There are no openings in the roof within 4 feet (1219 mm) of the fire wall; and

3.2. The roof is covered with a minimum Class A roof covering.

4. Buildings located above a parking garage designed in accordance with Section 509.2 shall be permitted to have the fire walls for the buildings located above the parking garage extend from the horizontal separation between the parking garage and the buildings.