1510.2.1 Type of construction.
BC § 1510.2.1
Bulkheads and penthouses shall be constructed with walls, floors and roof as required for the building. Exceptions: Where the total aggregate area of all rooftop structures does not exceed 33 percent of the area of the roof of the building upon which they are erected, the following shall apply: 1. Bulkheads on buildings of Type I and II construction. The exterior walls and roofs of such bulkheads with a fire separation distance of more than 5 feet (1524 mm) and less than 30 feet (9144 mm) shall be of at least 1-hour fire-resistance-rated noncombustible construction. Walls and roofs with a fire separation distance of 30 feet (9144 mm) or greater shall be of noncombustible construction. Interior framing and walls shall be of noncombustible construction.
2.Bulkheads on buildings of Type III, IV and V construction. The exterior walls of such bulkheads with a fire separation distance of more than 5 feet (1524 mm) and less than 30 feet (9144 mm) shall be at least 1-hour fire-resistance-rated construction. Walls with a fire separation distance of 30 feet (9144 mm) or greater from a common property line shall be of Type IV construction, or noncombustible construction. Roofs shall be constructed of materials and fire-resistance rated as required in Table 601. Interior framing and walls shall be Type IV or noncombustible or fire-retardant-treated wood construction.
