Insurers ask a question now that buyers in the 1990s never heard: does the house have Poly-B? Collingwood Plumbers gets the follow-up question often. How do I tell?
Where to look
Look wherever the supply pipe is exposed:
- At the water heater, where the cold supply and hot outlet connect.
- At the main shut-off, where the water comes into the house.
- Under kitchen and bathroom sinks.
- In an unfinished basement ceiling.
What Poly-B looks like
| Clue | Poly-B | PEX | Copper |
|---|---|---|---|
| Colour | Usually grey, sometimes blue or black | Red, blue or white | Copper |
| Marking | Often stamped PB2110 | Printed PEX | None, or a type letter |
| Flexibility | Flexible | Flexible | Rigid |
| Fittings | Crimp rings, plastic fittings | Crimp or expansion fittings | Soldered |
A faded pipe may have no readable marking. If you are not sure, a plumber can tell in a minute.
Where Poly-B hides in a finished house
In a finished basement the supply lines disappear into the ceiling within a metre of the water heater. That metre is usually enough. If the pipe leaving the water heater is grey plastic with crimp rings, assume the runs behind the drywall match it until somebody proves otherwise. The same applies to the short stub that comes out of the wall under a vanity: one visible piece tells you what the whole branch is likely to be.
A house that was partly re-plumbed can carry both. Copper at the water heater and Poly-B further along can happen where the tank was replaced later, so check more than one place.
The build years
Polybutylene went into Canadian houses from about 1978 to the late 1990s, and it was removed from the national plumbing code in 2005. In Collingwood and Meaford, houses from that era, and older houses re-plumbed during it, are the ones worth checking.
Why insurers ask
Poly-B fails mostly at its fittings, and heat and chlorinated water speed up its ageing. A leak behind a wall in a house nobody is watching is the water-damage claim insurers price. Some decline houses with Poly-B, some raise the deductible, some want a replacement plan.
Replacing it
Poly-B replacement maps every run, replaces it with PEX or copper, and pressure-tests before anything is closed up. A partial replacement of the exposed runs and fittings is a common first step.
Two good times to do it: during a renovation, when walls are open, and during a cottage shutdown, when the system is drained anyway. The cottage winterizing guide and the shutdown timing note cover the second.