Possible plastic plumbing problem

• Posted on April 3, 2017
• by mikew
• in Fix It & Use It
• No Comments.

Plastic plumbing piping is all the rage nowadays. The PEX supply piping is terrific stuff. What we have today has been developed on the shoulders of some earlier generations of problematic plastic piping. There is one in particular that is especially troublesome called polybutylene. A class action lawsuit brought this material to the forefront of attention.

The (mostly) gray-colored plastic piping can still be seen behind toilets and under sinks of houses built in the 1970’s through early 1990’s. It is further recognizable by the manifold, usually located in the garage, that looks like the plumbing equivalent of an electrical panel. This manifold controls the water supply to all fixtures in the home. Long, continuous lines run from this manifold with minimal joints to each of the fixtures in the house. The idea of less joints reduced the possibility of leaks. The polybutylene systems I have come across most commonly are in homes from 1994 built in the Arlington and Lake Stevens areas. Mobile homes from the 1970’s and early 1980’s also have this piping present. It is no longer allowed to be used in home construction.

Polybutylene supply lines for toilet

So what is the problem? There is a history of problems that every home owner should be aware of. It is believed that chlorine added to the water supply chemically alters the plastic material making it brittle. When one considers the abuse that piping sometimes endures under kitchen and bathroom sinks, it is understandable the vulnerability of the pipes. The standard residential water supply is 40-80psi in pressure and heated to 120-degrees Fahrenheit. Compromised piping is going to have a problem and most likely leak.

Polybutylene supply lines for sink

Polybutylene inlet and outlet line for hot water tank

What to do? If you have polybutylene piping, protect the piping from the impact of storage and garbage cans and monitor your piping for leaks. Consult a plumber for further evaluation. Ideally, replacement of all this piping is the best solution. It will be a worthwhile investment and reduce the added costs of potential leaks and water damage.