In Plain Language

Air admittance valves, one-way valves that let air into a drainage system without needing a full vent stack, must conform to the referenced ASSE standard for individual and branch-type air admittance valves.

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.