The Poly B glossary

The flexible grey plastic supply pipe installed in Canadian homes roughly 1978 to 1998, degraded from the inside by chlorinated water. The basics chapter tells the whole story.

The resin designation stamped on polybutylene pipe. Finding this print string is the definitive identification; grey colour alone is not.

The withdrawn Canadian standard polybutylene pipe was certified to. Seeing it in a print string means Poly B.

The grey plastic insert fittings used in many Poly B systems, embrittled by chlorine and responsible for the system’s worst failure record. Canadian installs more often used metal insert fittings, which fare better.

The metal band compressed around pipe and fitting to seal a joint. Poly B rings (usually copper-coloured) and PEX rings (usually black) are not interchangeable.

A fitting certified to join Poly B to a modern material. Ordinary push-fit and PEX fittings are not certified for Poly B; the fittings guide covers what is.

Cross-linked polyethylene, a standard modern replacement pipe (CSA B137.5). Comes as PEX-A, B or C by manufacturing method.

Polyethylene of raised temperature resistance: a non-crosslinked modern pipe (CSA B137.18, added to the National Plumbing Code in 2020) and the primary material our crews install. The pipe systems page compares the whole field.

The chlorine-resistance classification printed on modern PEX and PE-RT, tested under ASTM F2023. CL5 is the highest, certifying continuous hot recirculating service. The test exists because of Poly B.

Copper tube size: the shared outside-diameter convention that lets Poly B, PEX, PE-RT and copper use compatible fitting dimensions.

A layer on hydronic-heating tubing that blocks oxygen from seeping through the pipe wall and rusting the boiler and pumps. Poly B era heating loops typically lacked one; the radiant chapter explains the fix.

The municipal inspection done while new pipe is still visible, before drywall closes. Required in every city we’ve verified; see the permit centre.

Pressurizing the completed system to prove every joint holds before walls close. Standard practice and standard inspection evidence.

The contractor’s document stating full Poly B removal and the replacement material. The single most important piece of paper for your insurer.

An insurer declining to continue your policy at its end date, one rung on the escalation ladder Poly B homes can face. The insurance chapter is the step-by-step response.

Softer insurer responses to Poly B: a raised deductible specifically for water claims, or removing water damage coverage entirely while keeping the rest of the policy. Documented on the coverage tracker.

Alberta’s disclosure concept: a known defect a reasonable inspection would not reveal, which a seller cannot conceal. Whether Poly B qualifies is nuanced; the disclosure chapter covers it.

BC’s standard seller disclosure form, incorporated into the contract when signed, and the document at the centre of the province’s key disclosure case law.

The buried pipe carrying water from the municipal main to your house. Also made in polybutylene in the 1970s and 80s; usually the homeowner’s responsibility. The service line page has the details.

Full replacement of a home’s supply plumbing, including drywall access and restoration. The process page walks every stage.

A different composite pipe from a later era with its own separate class action. Frequently confused with Poly B; shouldn’t be.

Roughly 1978 to 1998 in Canada: from market introduction to the end of resin production. The basis for every likelihood verdict on this site’s checker, neighbourhood and city profiles.