The Ontario Building Code | Vent Pipe Flashing
(1) Flashing fabricated on site for vent pipesshall be fabricated from,
(a) copper sheet at least 0.33 mm thick,
(b) aluminum sheet at least 0.48 mm thick,
(c) alloyed zinc sheet at least 0.35 mm thick,
(d) lead sheet at least 1.73 mm thick,
(e) galvanized steel sheet at least 0.33 mm thick, or
(f) polychloroprene (neoprene) at least 2.89 mm thick.
(2) Prefabricated flashing for vent pipesshall be certified to CSA B272, "Prefabricated Self-Sealing Roof vent Flashings".
In Plain Language
Flashing fabricated on-site for vent pipes must be made from one of several listed materials and minimum thicknesses, such as copper, aluminum, or alloyed zinc sheet, ensuring durable, weatherproof roof penetrations.
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.