The Ontario Building Code | Combustible Glazing and Skylights
3.1.5.4. Combustible Glazing and Skylights
(1) Combustibleskylight assemblies are permitted in a buildingrequired to be of noncombustible construction if the assemblies have a flame-spread rating not more than,
(a) 150, provided the assemblies,
(i) have an individual area not more than 9 m2,
(ii) have an aggregate horizontal projected area of the openings="http://thehandyforce.com/windows/" title ="Window installer in Toronto">openings through the ceiling not more than 25% of the area of the ceiling of the room or space in which they are located, and
(iii) are spaced not less than 2 500 mm from adjacent assemblies and 1 200 mm from required fire separations, or
(b) 75, provided the assemblies,
(i) have an individual area not more than 27 m2,
(ii) have an aggregate horizontal projected area of the openings="http://thehandyforce.com/windows/" title ="Window installer in Toronto">openings through the ceiling not more than 33% of the area of the ceiling of the room or space in which they are located, and
(iii) are spaced not less than 1 200 mm from adjacent assemblies and from required fire separations.
(2) Combustiblevertical glazing installed no higher than the second storeyis permitted in a building required to be of noncombustible construction.
(3) Except as permitted by Sentence (4), the combustiblevertical glazing permitted by Sentence (2) shall have a flame-spread rating not more than 75.
(4) The flame-spread rating of combustible glazing in Sentence (2) is permitted to be not more than 150 if the aggregate area of glazing is not more than 25% of the wall area of the storey in which it is located, and,
(a) the glazing is installed in a building not more than 1 storeyin building height,
(b) the glazing in the first storey is separated from the glazing in the second storey in accordance with the requirements of Article 3.2.3.17. for opening protection, or
(c) sprinklers are installed in,
(i) any storey with combustibleglazing, and
(ii) the storey immediately above the storeywith combustible glazing.
(5) Combustiblewindow sashes and frames are permitted in a buildingrequired to be of noncombustible constructionprovided,
(a) each window in an exterior wall face is an individual unit separated by noncombustiblewall construction from every other opening in the wall,
(b) windows in exterior walls in contiguous storeys are separated by not less than 1 000 mm of noncombustible construction, and
(c) the aggregate area of openings in an exterior wall face of a fire compartment is not more than 40% of the area of the wall face.