(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.