The Ontario Building Code | Compression Fittings
7.3.4.8. Compression Fittings
(1) No compression fitting connecting to plain end pipe or tube shall be used in a plumbing system unless the pipe or tube and fittings are sufficiently stayed, clamped, anchored or buttressed so as to prevent separation during normal service of the system allowing for surge pressures.
In Plain Language
Compression fittings connecting to plain-end pipe or tube can't be used unless the pipe or tube and fitting are compatible, ensuring the fitting actually seals rather than just fitting loosely.
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.