The fire-resistance ratings of roofs which consist of a base slab of concrete with a topping (overlay) of an insulating concrete or with an insulating board and built-up roofing shall comply with Figures 722.2.2.3(1) and 722.2.2.3(2).
| For SI: 1 inch = 25.4 mm. |
FIGURE 722.2.2.3(1)
FIRE-RESISTANCE RATINGS FOR
CONCRETE ROOF ASSEMBLIES
| For SI: 1 inch = 25.4 mm. |
FIGURE 722.2.2.3(2)
FIRE-RESISTANCE RATINGS
FOR CONCRETE ROOF ASSEMBLIES
For the transfer of heat, three-ply built-up roofing contributes 10 minutes to the fire-resistance rating. The fire-resistance rating for concrete assemblies such as those shown in Figure 722.2.2.3(1) shall be increased by 10 minutes. This increase is not applicable to those shown in Figure 722.2.2.3(2).