(a) C-4 occupancies shall be governed by the story height and construction type limitations as follows:
(1) Fireresistive construction modified.
- (i) This shall be limited to three stories in height with a maximum of 3,000 square feet per story between exterior walls or 2-hour fire walls. Exit corridors and stair towers shall not be included in the 3,000 square feet.
(ii) All general provisions for fireresistive construction shall apply except that:
- (A) Roof framing and sheathing may be of wood; however, the roofing material shall be Class A, B, or C.
- (B) Floor construction shall be of incombustible material with a 1-hour fire rating.
(2) Noncombustible construction modified.
- (i) This shall be limited to two stories in height with a maximum of 3,000 square feet per story between exterior walls or 2-hour fire walls. Exit corridors and stair towers shall not be included in the 3,000 square feet.
- (ii) Construction shall be 1-hour rated construction in which bearing walls, columns, beams, other supporting members, ceiling/roof assemblies, floor/ceiling assemblies, stairways, and other openings through floors are of 1-hour rated construction.
- (iii) Roof framing and sheathing may be of wood; however, the roofing material shall be Class A, B, or C.
(3) Ordinary construction modified.
- (i) This shall be limited to two stories in height with 3,000 square feet per story between exterior walls or 2-hour fire walls. Exit corridors and stair towers shall not be included in the 3,000 square feet.
- (ii) Construction shall be 1-hour rated construction in which bearing walls, columns, beams, other supporting members, ceiling/roof assemblies, floor/ceiling assemblies, stairways, and other openings through floors are of 1-hour rated construction.
- (iii) Roofing shall be Class A, B, or C.
(4) Wood frame construction modified.
- (i) This shall be limited to two stories in height with a maximum of 2,000 square feet per story between exterior walls or 2-hour fire walls. Exit corridors and stair towers shall not be included in the 2,000 square feet.
- (ii) Construction shall be 1-hour rated construction in which bearing walls, columns, beams, other supporting members, ceiling/roof assemblies, floor/ceiling assemblies, stairways, and other openings through floors are of 1-hour construction.
- (iii) The roofing material shall be Class A, B, or C.