602.4.2 Cross-laminated timber in exterior walls.
BC § 602.4.2
Cross-laminated timber (CLT) complying with Section 2303.1.4 shall be permitted within exterior wall assemblies not less than 6 inches (152.4 mm) in thickness with a 2-hour rating or less, provided the exterior surface of the cross-laminated timber (CLT) is protected by one of the following: 1. Fire-retardant-treated wood sheathing complying with Section 2303.2 and not less than 15/32 inch (11.9 mm) thick; 2. Type X gypsum board not less than 5/8 inch (15.9 mm) thick; or 3. A noncombustible material.
