What is Polybutylene Piping?

Polybutylene piping was a plastic plumbing material made and installed from 1978 to the mid-1990s. Like many new and innovative building materials, manufacturers and fans touted it as the pipe of the future. Plumbers loved it because it was cheaper and flexible making it quicker and easier to install.

Polybutylene advertisers claimed installation took half the time of copper pipes.

However, the hype did not match the reality. Sadly, polybutylene water pipes experienced a high failure rate causing a lot of water damage. Eventually, home owners filed a class action lawsuit which resulted in a 950 million dollar class action settlement.

Quick Facts About Polybutylene

• Polybutylene is a form of plastic resin.
• Polybutylene plumbing is also known as "PB pipes", "poly pipe", and "quest" pipe. However, Quest was just one brand of polybutylene pipes.
• You can identify it by its gray color and the "PB 2110" stamp.
• Although many theories circulate on the internet, there is no known definitive cause for its higher rate of failure.
• It is not true that the copper fittings and other metal fittings are fine and the plastic fittings are not.
• It is not true that the pipes do not experience failure in well water systems.

PolyButylene Myths

Myth: Only the acetal fittings were defective.

This myth might stem from the fact that polybutylene manufacturers conceded there were some issues with the acetal fittings. Furthermore, they claimed they had addressed these issues already. Plus, they started manufacturing metal fittings.

However, the class-action lawsuits did not limit their complaints to the fittings. The pipes fail as well. Some plumbers theorize that chlorine in the water oxidizes and degrades the fittings and the pipes which causes small cracks and pinhole leaks.

Myth: If it hasn't leaked yet, it's not going to leak.

The prevailing theory is that chlorine and other additives in the water oxidate and degrade the pipe. Hard bends and turns accelerate this deterioration. Polybutylene piping still develops leaks today.

Myth: Only polybutylene pipes on public water supply leak.

The settlement did not exclude homeowners on well water, because homes on well water also had high rates of failure.

Should You Replace Polybutylene?

Obviously, if the pipes leak, you should replace the pipes. Otherwise, you could have just the leaks repaired, but your risk for more leaks is high.

If your pipes aren't leaking, it's not as clear cut. Polybutylene pipe failure is not absolute. In other words, it's not guaranteed that old polybutylene pipes are going to leak.

There are two major considerations. First, is that one leak can easily cost more than replacing the pipe in the first place. Small leaks lurk for months before being noticed. Meanwhile, they cause extensive rot, mold, and property damage.

Second, is how home insurance companies handle these piping systems. If your insurance company knows you have PB pipes, they may not cover you, or charge higher premiums. If they don't know, and you do have a leak, they will likely drop you after the leak. Obviously, replacing your insurance will be more expensive.

Even if your polybutylene pipes aren't leaking, it is usually cost effective to be proactive and replace the pipes.

Bottom Line

Polybutylene pipes were plastic pipes installed from the late 1970s to the mid-1990s. Extensive pipe failures resulted in a class-action lawsuit. A settlement was reached and paid out over 1 billion dollars.

If you have these pipes, it's a good idea to consult with a professional plumber and have your pipes replaced with new pipes.