The Ontario Building Code | Materials
9.26.4.2. Materials
(1) Sheet metal flashing shall consist of not less than,
(a) 1.73 mm thick sheet lead,
(b) 0.33 mm thick galvanized steel,
(c) 0.33 mm thick copper,
(d) 0.35 mm thick zinc, or
(e) 0.48 mm thick aluminum.
In Plain Language
Flashing materials used at roof intersections must conform to the standards referenced in this article.
This is a plain-language summary of the 2012/2017 Ontario Building Code text above, for general understanding only and not a substitute for the Code. Always confirm current requirements against the 2024 edition (O.Reg. 163/24) or a qualified professional before construction.