Ask the Expert: What is the Problem with Polybutylene Piping?

Sean Moss
February 18, 2015

Q: What is Polybutylenepiping and why is it such problem?

A: Polybutylene is a plastic water supply piping material that was used extensively from the early 1980s up until the mid 1990s. In BC it can be easily identified by its light grey colour and PB stamp right on the pipe. However, it also came in blue red and black. When it first arrived on scene, PB appeared to be an excellent substitute for copper, due to its flexibility and lower cost.

Polybutylene has been responsible for thousands of leaks in North American homes due to failures, most commonly at the plastic or “acetal” fittings (where pipes join). Chemicals in the water, such as chlorine cause micro tears and erosion within the pipes from the inside out. Detecting it is impossible, so expensive leaks happen without warning. As a result, polybutylene has been the catalyst for several lawsuits across North America.

Furthermore, insurance providers have learned an expensive lesson when it comes to this type of piping, exercising much caution, insisting on complete replacement in some cases, higher premiums or outright refusal to insure.

The pipes are oxygen permeable, which does not bode well for radiant and in-floor heating systems. As oxygen in the water passes through the pipe walls, the metal components in the boiler begin to rust. Over time, this significantly reduces their service life… Adjustments that can be made of course, but close monitoring and annual maintenance are highly recommended.

If your home or the home you decide to buy has polybutylene piping, contact your insurance provider to determine your options. You will also want to call a plumber or home inspector to evaluate your plumbing system.

Sean Moss
Sean Moss is a home inspector focusing primarily on residential properties with specialized knowledge in mold and building envelope science. He has been featured in Vancouver Magazine, Richmond News and The Jewish Independent and he also shares his knowledge through articles and workshops. Call Sean on 604-729-4261, visit his website and see his rating on review website HomeStars.