Polybutylene Piping – What is it?
Polybutylene piping (PB) is plastic piping that was used as a plumbing supply pipe from 1978 to 1995. The supply piping in the home is used to bring water into the house and supply the various fixtures such as water heaters and other appliances that utilize potable water. We still use plastic piping today, most commonly in the form of cross-linked polyethylene (PEX) or chlorinated polyvinyl chloride (CPVC). So why haven’t you heard about PB? It was used in up to 10 million homes, primarily in the sunbelt area of the country, and manufacturing was ceased in 1996 after numerous claims of failure.
So why would I want to know more about it? Home inspectors rarely come across PB in our area, but we do find it occasionally. PB piping can be identified in a few ways. It is typically grey in color and used for supply piping or heat piping and is not part of the drain/waste/vent system. It is often labeled “PB2110”. Many more common issues like lead water mains are frequently discussed because they were present much more often. PB piping on the other hand is rarely found and when we do identify it in homes, the parties involved frequently have little or no knowledge about its presence or potential for failure. While rare, I have personally found it present in the north shore area, so it has been used here.
So, what if I do find it? If you do own a home with it present, you should be concerned. The problem is a failure, and it is notorious for failures at pipe connections and even in the piping itself in some areas. The other issue is when it is used, it’s often used in large portions of the home. If all the water piping present is PB piping you can have a large potential for failure. While some inspectors claim that failure typically would have happened already if it was going to happen, I have only seen this material with numerous poor connections and corroded areas and failure has appeared imminent. My recommendation is to replace all PB piping present. The cost of replacement is a better option than the high risk of expense if a failure did occur.