If you are looking at a house or townhouse built in the late 1980s or early 1990s, the plumbing question will probably come up. It is about the grey plastic pipe known as Poly-B, short for polybutylene. Many Metro Vancouver homes of that period had it installed, and a lot of them have since had it replaced.
What it is and when it was used
Poly-B is a flexible plastic pipe used for domestic water supply, the pipes that carry pressurized water to taps, showers and appliances. In Canada it was widely installed from about the mid-1980s to the mid-1990s, which overlaps the large wave of wood-frame housing built in that period. It is not used for drains.
It is usually grey, sometimes blue or black. Printed on the side you may find "PB2110" or similar. It runs in long, bendable lengths with fewer joints than copper, and it is joined with crimp-style or push-fit fittings.
It is not the same as PEX. PEX is cross-linked polyethylene, a different material, which is used today and has a different record.
Why it has a reputation
The issue is mainly at the fittings. The early fittings were made of acetal plastic, and the combination of the fitting, chlorinated water and time has been associated with cracking, flaking and leaks. Leaks tend to happen without warning at connection points, and many of those points are inside walls and ceilings. A slow leak in a wall can go on for a long time, then show up as a stain, a soft floor or mould.
Some Poly-B systems were installed with metal fittings, and these have generally had fewer problems. But the pipe itself is also a concern for some, and insurers often treat all Poly-B the same way. Not every system has failed. It is a material with a known failure pattern, and a house with it deserves a plan.
Where inspectors look
A visual inspection can only see exposed pipe and fittings. Typical places are:
- at the water heater
- at the main shut-off and the pressure reducing valve
- in the crawl space or unfinished basement, along joists
- under sinks and at the laundry
- in the attic, where some supply lines run
We note whether Poly-B is present, what the fittings look like, any corrosion, staining or moisture, and where the pipe was not visible. We cannot see inside finished walls, and we cannot tell you when a fitting will fail. A moisture meter may point to a leak that is already happening.
Insurance and mortgages
This is where Poly-B becomes a purchase decision. Practices differ between insurers and change over time. In broad terms:
- some insurers will not cover a house with Poly-B
- some will cover it if the pipe is replaced, or if it is replaced within a time limit
- some will cover it with a higher premium, or exclude water damage
- some will not mind if it has been inspected and has metal fittings
Phone your insurer, describe what the inspection found, and get their requirements in writing before you remove subjects. A mortgage lender may also have views, particularly in strata buildings.
Condos and townhouses
In a strata property, the answer depends on who owns the pipe. Pipes inside the unit that serve only that unit are normally the owner's. Shared risers and mains are normally the strata's. If a townhouse complex has Poly-B throughout, ask whether the strata has a repiping plan, whether any levies have been charged, and whether other owners have had leaks. The strata documents are where the answers are.
Replacing it
Repiping is done with PEX or with copper. It generally means opening walls and ceilings to run the new lines, then repairing the finishes. Some plumbers can do much of it through small access cuts, and some owners do it in stages, starting with the most accessible runs. A quote from a plumber who has looked at the house is worth more than any rule of thumb, because access varies enormously.
If you plan to renovate the kitchen or the bathrooms anyway, doing the repipe at the same time costs less than doing it separately.
What to do as a buyer
- Find out from the listing and the seller whether the house has been repiped, and ask for the plumber's invoice or the permit.
- Read the inspection report for the words "Poly-B", "polybutylene" or "grey plastic pipe". Note where it was seen.
- Phone your insurer. Ask what they require, and how soon.
- Get a plumber's written quote for repiping if it is still there.
- Use the quote. Ask for a price adjustment, a credit, or a plan, or accept that the house has a repiping cost ahead.
What to do as an owner
If you already own a house with Poly-B and it has not leaked, you have time to plan. Know where your main shut-off is, and check that it works. Look at the exposed fittings now and then. Consider a leak detector or an automatic shut-off valve. And keep an eye on your water bill, which rises when there is a hidden leak.
In short
Poly-B is common in houses from the late 1980s and early 1990s, and it is a known risk at the fittings. It is not an emergency, and it is not nothing. Treat it as a repair that is coming, and decide with a quote and your insurer's rules in hand.