Polybutylene (PB) piping plastic water supply line was introduced to the plumbing industry in the 1970s and virtually accepted as the "pipe of the future. " Its proponents touted its low cost when compared with copper piping and its ease of installation. Gorman Rupp Mexico As an old-school plumbing contractor and former plumbing and building inspector, I was skeptical and lost many jobs when my competitors submitted their bids using the new plastic water piping; I stubbornly stuck with copper. It wasn't long before my instincts proved correct and I began to get jobs replacing the defective polybuylene piping that had been so roundly embraced, across the board, by the plumbing industry.

Apparently, no one had tested the new material rigorously; it begins to slowly break down when in contact with chlorinated water. Unfortunately, in most of Southern California (where I live) the public drinking water contains more chlorine than the average swimming pool. Class action suits were settled and millions of dollars were set aside to replace most of the defective plastic water supply line. It is estimated that more than ten million properties nationwide have been plumbed with polybutylene during the eighteen, or so, years it was used. If you own a property that has this material, you might want to consider replacement as soon as possible. When checking your property note that inside polybutylene water lines are usually grey. Outside lines can be grey, blue, or black.

It does not fail the way copper or iron pipe does, where a slight leak develops from a pin hole or a deteriorated thread and then gradually gets worse. When PB fails, it generally comes apart completely all at one time and causes severe flooding and damage. If you are away from your home during a PB failure, water could pour full force into your home until someone comes home to turn off the water main valve. Replacement is the only effective permanent solution for this kind of tubing: temporary repairs should be quickly followed with replacement of the entire line.

I would also strongly suggest to anyone considering purchasing a property that has PB plumbing, that they set aside a realistic amount of money to have it all replaced, along with the cosmetic repairs required after its installation. Copper piping has been used for centuries for drinking water. Ironically, even copper piping is beginning to show deterioration from the excessive amounts of chlorine used in municipal water districts. People are beginning to realize that the only practical solution for these problems are whole house water filters.