Roof Sheathing Thickness or Rating
(1) The thickness or rating of roof sheathing on a flat roof used as a walking deck shall conform to either Table 9.23.14.5.A. or Table 9.23.14.5.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 9.23.15.7.A. or Table 9.23.15.7.B.
(3) Asphalt-coated or asphalt-impregnated fibreboard not less than 11.1 mm thick conforming to CAN/ULC-S706.1, “Wood Fibre Insulating Boards for Buildings”, is permitted to be used as a roof sheathing over supports spaced not more than 406 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.
Article 9.23.15.7. Ontario Regulation 332/12 Building Code, Information published by oncodes.ca for educational purposes only.
