The Ontario Building Code | Offset Relief Vents
7.5.7.4. Offset Relief vents
(1) Except as provided in Article 7.5.7.1., the minimum size of an offset relief ventis permitted to be one size smaller than the size of the stack vent.
In Plain Language
This article repeats and extends the offset relief vent requirements for a related venting method covered in this Subsection, addressing the same long-horizontal-offset condition described elsewhere.
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.