Polybutylene Piping: What You Should Know

Date Published: March 18, 2024

When it comes to residential construction, we are always trying to push forward as a society. We are searching for the most cost effective, efficient, and long-lasting building techniques. This has certainly yielded many successful methods and materials throughout history…but not always. In this blog, we will discuss a particular plumbing pipe that caused serious issues for thousands of homeowners nationwide – Polybutylene Piping.

What is Polybutylene Piping?

Polybutylene (aka Poly B or PB) is a plastic pipe material that was utilized for plumbing supply lines from 1978 to 1995. Similar to Kitec plumbing, it was more affordable than copper and easier to install. PB was also hailed for its flexibility and resistance to freezing. It can usually be identified by its gray color, but it is also known to come in blue, black or white. It is also generally marked with the code “PB2110.”

Throughout the late 70s through the late 90s, PB became a very popular alternative material for many plumbers in the US and Canada, and it was said to have been installed in around 10 million homes during its prominence.

However, it soon became apparent that this style of plumbing was quite problematic. Leaking and pipe damage became commonplace in many homes with Poly B piping. What initially seemed to be a viable alternative to copper, soon became the cause of plumbing nightmares all across North America.

Image Sourced from: https://www.linkedin.com/pulse

What’s Wrong with Polybutylene Piping?

Sensitivity to Disinfecting Chemicals

Water treatment facilities will often add chemicals, such as chlorine, to potable water supplies. This is a common practice used to kill any harmful germs or bacteria present in the water. Unfortunately, it turned out that Polybutylene was sensitive to these types of chemicals.

Prolonged exposure to these disinfectants would cause the piping to flake away from the inside out. Over time this would lead to leaks, cracks or ruptures. Furthermore, as the plastic elements break down, they can enter the water supply and pose potential health threats.

This type of defect is particularly deceiving because it cannot be identified by simply looking at the pipe. It may seem perfectly fine from the outside, but it’s actually deteriorating on the inside.

Faulty Fittings

Plastic fittings were commonly used for Poly B piping. The piping segments would be slid over the plastic fittings then crimped down with metal rings. However, these fittings were not very reliable and prone to cracking and leaking over time. Just like the piping itself, the plastic fittings are vulnerable to chemical deterioration.

Damaged Polybutylene fitting

Damaged polybutylene fitting. Image sourced from: https://sagewater.com

Installation error was also sometimes the cause of fitting issues. During installation, the metal crimping rings must be tightened around the junction between pipe and fitting. But there was a super fine line between, too loose, too tight, or just right. As a result, fittings would be secured too tightly, causing cracking, or fastened too loosely resulting in leaking.

A good portion of plumbing is hidden behind drywall. So in many cases, PB pipes would start to leak into wall, ceiling or floor cavities unbeknownst to the homeowner. This would result in severe water damage or mold issues. And that is why many plumbers will often recommend a full piping replacement.


Poly B was a real problem for many homeowners – so much so that class action lawsuits were filed against its manufacturers for a settlement of over $1 billion. The lawsuit, entitled Cox v. Shell Oil Company, granted money to homeowners who experienced damages or losses caused by PB piping failure. If you have read our article about Kitec plumbing, you will note that it has had a very similar history to Polybutylene.

Resale, Mortgage, and Insurance Issues

The lawsuit may have helped many Poly B homeowners to replace the problematic plumbing. However, the piping has certainly not been eradicated from all households.

Some fortunate homeowners might not have any issues with their PB up to this point. But even so, the presence of Polybutylene could still negatively affect the value of their home. After getting a home inspection, prospective buyers will surely learn about the piping and how it has a high probability of failure. Knowing that they will likely have to deal with pricy plumbing repairs or eventually get the PB replaced altogether might discourage a buyer from committing to a deal. Homeowners with Poly B will likely have to get it replaced or disclose the presence of the piping in any future transaction, resulting in negotiations or concessions.

This same concept applies to mortgages and insurance. Mortgage companies might be hesitant to lend money for a home that’s prone to costly damages. And insurance companies might require higher premiums or deny coverage completely. If coverage is given, a claim might be denied if the piping causes water damage.

PB piping

Image sourced from: https://boldcityhi.com

Inspecting for PB Piping

As a seasoned home inspection company, we realize that even if there are no issues at the time of inspection, it is important know what problems could happen in the future. We want our clients to be armed with as much knowledge as possible, in order to make the best decision possible.

So when we see a material like Polybutylene – one that has such a potential for failure – we address it with the appropriate seriousness. We will always recommend further evaluation from a qualified plumbing specialist.

Here at Scott Home Inspection, it is our goal to provide you with the most professional, thorough and unbiased home inspection. If you are in need of Colorado-based inspection services, we hope that you will consider Team Scott. Visit us online or contact us to schedule you services today!

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About the Author: Chris Kimmel

Chris Kimmel worked as an Associate Home Inspector for two years, handling numerous services including sewer scope inspections, pest inspections, mold air sample testing, radon testing, and water quality testing. Chris now works with Scott Home Inspection as a Content Writing Specialist.

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