The Ontario Building Code | Check Valves
7.6.1.10. Check Valves
(1) A check valve shall be installed at the building end of the water service pipe where the pipe is made of plastic that is suitable for cold water use only.
In Plain Language
Check valves are required at specified points in the water distribution system to prevent backward flow that could contaminate the potable water supply.
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.