Poly-B (polybutylene) is a grey, flexible plastic water supply pipe that was widely installed in Canadian homes from the late 1970s until the mid 1990s as a cheaper alternative to copper. It is now known to deteriorate from the inside as it reacts with chlorinated water, which leads to unexpected leaks and sudden failures. If your Durham Region home was built in that window, it is worth checking.

Why Poly-B fails

Chlorine and other disinfectants in municipal water react with the plastic over decades and break down the inner wall of the pipe. The damage is invisible from the outside. Pipes can look fine while becoming brittle, and the plastic and metal fittings used with them are a common failure point. When a failure happens it is usually sudden: a fitting lets go or a pipe splits, often inside a wall or ceiling where the water damage spreads before you notice.

How to identify Poly-B in your home

Look at the visible plumbing in your basement, utility room and under sinks. Poly-B is grey, flexible plastic, often stamped with "PB2110" along its length. The fittings are typically grey plastic or copper crimp rings. If your home was built between roughly 1978 and 1995 and you see grey plastic supply lines, it is very likely Poly-B. Do not confuse it with PEX, which is usually white, red or blue and has been the standard replacement material for years.

The replacement process

A Hayes Plumbing technician inspects every visible run, estimates the in-wall sections and provides a written quote. We replace Poly-B with PEX, a flexible cross-linked polyethylene pipe that resists freeze damage and is designed for a long service life. We plan the smallest practical drywall openings, replace each run, pressure-test the new system and leave the openings ready for patching. For most homes the work takes a few days and we stage it so water is only off for short periods.

What it costs

Whole-home repiping is priced per project after a walkthrough, because the number of fixtures, the number of storeys and how much of the plumbing is behind finished walls all change the scope. As a planning range, the Hayes Plumbing 2026 cost guide lists a full line replacement (leak and drain line repair) at $3,000 to $10,000; whole-home repipes are quoted after a walkthrough. We confirm the price in writing before we start, and financing through Financeit is available.

Insurance implications

Many insurers ask about Poly-B at renewal. Depending on the company, it can mean higher premiums, limits on water damage coverage or a request to replace the piping. Replacing Poly-B removes that question from your policy and protects you from a denied claim after a failure. Keep the invoice from your repipe; insurers often ask for it.

When to prioritize replacement

  • You have already had a Poly-B leak or a fitting failure. The first failure is usually a warning that the rest of the system is at the same age and condition.
  • You are planning a bathroom or kitchen renovation. With walls already open, repiping is far less disruptive. See our bathroom renovation service.
  • Your insurer has flagged Poly-B at renewal.
  • You are selling. Buyers and home inspectors in Durham Region look for it.

Book a free assessment

Call (905) 576-3043 or request an estimate. We will confirm whether you have Poly-B, explain the options and give you a written price. Learn more on our Poly-B replacement page.