The Ontario Building Code | Tracer Wire
7.2.11.3. Tracer wire
(1) Except as provided in Sentence (2), a 14 gauge TW solid copper light coloured plastic coated tracer wire shall be attached to every non-metallic water service pipe or fire service main.
(2) Where a water service pipe or fire service main is detectable without the tracer wire referenced in Sentence (1), the tracer wire may be omitted.
In Plain Language
Non-metallic (plastic) water service pipe must have a tracer wire, a copper wire run alongside it, so utility locators can find the buried pipe electronically later, since plastic pipe can't be detected the way metal pipe can.
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.