The Ontario Building Code | Roof Coverings
3.1.15.2. Roof Coverings
(1) Except as provided by Sentences (2) and (3), every roof covering shall have a Class A, B or C classification as determined in accordance with Article 3.1.15.1.
(2) A roof covering is not required to have a Class A, B or C classification for,
(a) a tent,
(b) an air-supported structure, or
(c) a buildingof Group A, Division 2 occupancy not more than 2 storeys in building heightand not more than 1 000 m2 in building area, provided the roof covering is underlaid with noncombustiblematerial.
(3) Combustible roof coverings on buildingswithin the scope of Article 3.2.2.43A. or 3.2.2.50A. shall have a Class A classification.
3.1.16. Fabrics