Old house plus poly plumbing piping equals disaster - part I

By: Conrad Neuf , Contributing Writer
In: Home Improvement Tips, Old House Construction

Let me state it right up front: if your old house has any polybutylene plumbing piping and is on a public water system, you are either going to have a major water leak sometime in the future or you have already had one. Unfortunately, my home falls into the latter category and after suffering extensive damage from a decayed line, I have seen the light.

Polybutylene plumbing piping: a nightmare waiting to happen

Polybutylene piping, or poly for short, first began appearing in new homes in the late 1970s and quickly caught on in many parts of the country. And why wouldn't it - the new pipe was easy to work with, its joints didn't require soldering, and even more important to builders and contractors, it was much less expensive than the copper supply lines being installed. In an industry where profit margins could sometimes be low, any chance to lower building costs was welcomed.

As a result, poly was put into many new and remodeled homes during the 80s and early 90s. But then something happened that caused it to lose a bit of its luster: water leaks began occurring in increasing frequency.

At first the leaks were blamed on faulty connections done by hasty or untrained plumbers. Connections required using a special tool, and if care wasn't taken when squeezing it tight, the joint could loosen over time and cause a leak. That's where things stood when I purchased my old house 23 years ago and discovered someone had updated many of the ancient cast iron water lines with poly.

Plumbing contractors I knew at the time still believed in poly, so I borrowed a crimping tool and set about installing a few additional exterior water lines using the material. And now, as Paul Harvey used to say, comes "the rest of the story."

Why you need to replace your poly plumbing piping ASAP

When a home water line under pressure breaks, the damage that results can be extensive and costly - especially if a leak occurs when the house is empty and the water runs for a while. Home-builders and remodeling contractors during the 90s began receiving numerous phone calls from past customers with large plumbing leaks that, in some cases, caused thousands of dollars of destruction. Polybutylene piping, once thought of as the "pipe of the future," was damaging homes and belongings.

Studies were done and the findings that came to light would have been nice to know before poly plumbing piping had been installed in thousands of new and old homes. It turned out that some of the chemicals used to treat water in public systems could cause poly piping to gradually decay from the inside out. When the decay reached a certain point, the outer shell of the pipe simply gave way.

In Part II, I'll describe how poly piping can be identified, what kind of damage may result when it breaks, and how an emergency repair can provide a temporary solution. Unfortunately, I won't have to look too far for a specific example as it happened recently in my own old house.