Poly-B plumbing: do you have to replace it all before buying?

Polybutylene (Poly-B) is a grey plastic water pipe installed in many houses and condos between the late 1970s and the mid-1990s. It ages badly: it becomes brittle, cracks and leaks, often without warning.

Many insurers refuse to cover water damage or require its replacement. You can buy a house that has it, but budget its replacement and tell your insurer.

A grey (sometimes blue or black) flexible pipe about 1.5 cm in diameter, marked “PB2110”, visible at the water heater, under sinks, at the basement ceiling. The original plastic or crimped aluminum fittings are the weak points.

The inspector notes it where visible. They cannot say what share of the system is still Poly-B behind the walls: that is a question for the seller, the condo syndicate or a plumber.

Your first call is to your insurer: some refuse, others accept with a surcharge or a replacement deadline. Without home insurance, no mortgage.

In a condo, Poly-B in the common areas is the syndicate’s responsibility. Check the contingency fund and the minutes to see whether replacement is planned and funded.

Full replacement of a house’s plumbing with PEX or copper most often runs from thousands to over ten thousand dollars, depending on size, number of bathrooms and finishes to open and close.

These are orders of magnitude. Confirm them with quotes.

Before you buy, here is what I would do.

1. Call your insurer before lifting the inspection condition, report in hand.
2. Ask the seller or the syndicate what has already been replaced, with invoices.
3. Get a plumber’s quote for replacing the rest, and negotiate on that basis.

When your inspector flagged Poly-B, I put it among the priorities, I add the insurer and the syndicate to the questions to ask, and I give an order of magnitude when the report allows it.

Does your report mention this? Send it to me. In five minutes, I tell you what is priority, what to have checked and what to ask the seller.

It has not been accepted by plumbing codes for new installations since the 2000s, but nothing obliges an owner to remove existing pipe.

Not necessarily within days, but a short-term replacement plan is the norm, and the insurer may impose it.

No. PEX is a different material, widely used today. Its fittings, not the pipe, call for careful installation.