(1)
The thickness or rating of roof sheathing on a flat roof used as a walking deck shall conform to either Table 9.23.15.5.-A or 9.23.15.5.-B for subfloors.
(2)
The thickness or rating of roof sheathing on a roof not used as a walking deck shall conform to either Table 9.23.16.7.-A or Table 9.23.16.7.-B.
(3)
Asphalt-coated or asphalt-impregnated fibreboard not less than 11.1 mm thick conforming to CAN/ULC-S706.1, “Standard for Wood Fibre Insulating Boards for Buildings,” is permitted to be used as a roof sheathing over supports spaced not more than 400 mm o.c., provided the roofing consists of
(a)
a continuous sheet of galvanized steel not less than 0.33 mm in thickness, or
(b)
a continuous sheet of aluminum not less than 0.61 mm in thickness.
(4)
All edges of sheathing described in Sentence (3) shall be supported by blocking or framing.
Table 9.23.16.7.-A Thickness of Roof Sheathing
Forming Part of Sentence 9.23.16.7.(2)
Table 9.23.16.7.-B Rating for Roof Sheathing When Applying CSA O325
Forming Part of Sentence 9.23.16.7.(2)
