Home Inspection Problems: Polybutylene Pipe

While home inspectors in San Antonio are running into Polybutylene piping less often than they used to, home owners in Texas need to be aware of PB piping.

What is Polybutylene Pipe?

Polybutylene is a type of plastic that was utilized widely in the plumbing industry from 1978 until 1995 as water supply pipe. Once thought to be the future of piping due to its affordability and the speed of installation, polybutylene began to replace the more expensive (in both labor and materials) copper pipe. It was most commonly used in mass-produced “track” homes during the 1980’s and into the early-mid 1990’s, primarily in the Southwest United States where populations where exploding and builders couldn’t keep up with the demand for housing, although still found in the Midwest and on the East-Coast as well.

Polybutylene was used for both larger, “Main” water supply pipes found underground leading into your home, as well as the smaller, “Branch” water supply lines used indoors to distribute water throughout your home. While even at its peak, polybutylene didn’t overtake copper as the most used water piping material in San Antonio or the rest of the country, it is estimated that between 6 and 10 MILLION homes built from 1978 to 1995 had polybutylene piping. That was approximately 20% to 25% of all homes built in the US during those years.

Why is Polybutylene Piping a Problem?

Both the joints (made of acetyl plastic) of the pipe and the pipe itself leak and fail at a rate significantly higher than previously used piping materials such as copper and even galvanized metal pipes. How this was not discovered before this product became so widely used is well beyond me, but scientists have theorized that contaminants and anti-oxidants used in many municiple water supplies, such as chloramine and fluoride, cause the pipe to degrade at a rate faster than anticipated. The corrosion causes the otherwise flexible pipe to become hard and brittle, causing small cracks and leaks that can go unnoticed and left to cause even more damage than a larger, more obvious leak.

You can bet that lawsuits were filed by angry homeowners, distraught that the new home they built already has leaking pipes. IPC plumbing code responded by outlawing Polybutylene piping in 1995, but the damage was done to all the homes built with it.

How Do You Know If You Have Polybutylene Pipe in Your House?

First, If you live in San Antonio, you can have one of the home inspectors from Ensure Home Inspections swing by and take a look. If you don’t live near San Antonio, then call a local Home Inspector or Plumbing Professional. You really need a professional to verify this for you.

Secondly, there are some visual indicators and context clues to help determine if you have Polybutylene pipe in your home:

• Polybutylene was made in a variety of colors, but most commonly found as grey pipe, as well as blue or black pipe.
• It is commonly found as either 1/2″ or 1″ pipe.
• Polybutylene is labeled with the letters “PB”, commonly near the ASTM lettering, although this lettering is commonly not visible or worn off of old pipe.

How Do You Know if the Polybutylene Pipes Will Fail?

Unfortunately, you don’t. While it’s no guarantee that the PB plumbing will fail, the damage that they can cause when they do necessitates their replacement as soon as their discovered. If a Home Inspector observes anything they even think is polybutylene pipe, they should recommend further evaluation by a licensed plumber, and if confirmed polybutylene pipe, replacement of pipe as soon as possible.