The Ontario Building Code | Stack Vents
7.5.4.1. Stack vents
(1) The upper end of every soil or waste stack shall terminate in a stack vent and the stack vent shall terminate in open air outside the building,or connect directly or through a header to another stack vent or vent stack that does terminate in open air outside the building.
In Plain Language
The top of every soil or waste stack must terminate in a stack vent that either extends into open air outside the building or connects to another vent, so the whole stack stays properly ventilated.
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.