What is Polybutylene?

Polybutylene (PB) is a form of plastic resin that was used extensively in the manufacturing of water supply piping from 1978 to 1995.   PB was still installed in new sub-divisions up to mid-1998, due to the amount of pipe still on the market after production halted.  The piping systems were used for underground water mains and as interior water distribution piping. Polybutylene pipes on interior water lines are typically gray, black, or white and yard service lines (exterior) are typically blue, black or gray in color with a dull finish. Blue PB pipe also known as “Big Blue” was the most commonly used pipe for the exterior.  PB was not used for drains, waste or vent pipe, but was sometimes used for water heater temperature and pressure relief lines and condensate lines for A/C units and Ice makers lines.  Industry experts believe it was installed in at least 6 to 10 million homes. That is an estimate of 1 in every 4-5 homes built during 1978 to 1995. PB was almost the exclusive material used in plumbing inexpensive tract homes and manufactured homes.  It is most commonly found in the “Sun Belt region” where residential construction was heavy through the 1980’s and early-to-mid 90’s.  In Arizona it is estimated that PB has caused damage in over 100,000 homes. In our experience we have seen PB through out all of Tucson and surrounding areas. It is not just limited to one particular area, builder or subdivision. 

Is PB Still being used?

Manufacturers and other defenders of PB piping insist the product on the market does not deserve its bad reputation.  Manufacturers of raw PB, including Shell Oil, Hoeschst Celanese Corp., and DuPont De Nemours; blame the bulk of leaks and ruptures on improper installation.  PB is and can still be used for private use in Tucson. And the city council added it to the uniform plumbing code in 1991. Caution seems to be the final word regarding PB use. 

How to tell if you have PB.

Homeowners often cannot determine what type of plumbing they have by inspection, as stubs to sinks and toilets generally use poly-to-copper connections.

Exterior:

PB underground water mains are usually blue, but may be gray or black (do not confuse black poly with polyethylene pipe).  It is usually ½” to 1” in diameter and is found entering your home through your crawlspace and frequently it enters the home near the water heater.  Your main shut off is attached to the end of the water main. Also, you should check at the water meter that is located at the street, near the city main.  It is wise to check at both ends of the pipe, because we have found cases where copper pipe enters the home and PB is at the water meter. 

Interior:

PB used inside your home can be found near the water heater, running across the ceiling in unfinished crawl spaces, coming out of the walls to feed sinks and toilets.  Warning: some times copper “stub outs” are found where the pipe exits a wall to feed fixture, so seeing copper pipes does not mean that you do not have PB.

Reasons PB has failed:

It is believed that oxidants in the public water supplies, such as chlorine, react with PB piping and acetal fittings causing them to become brittle.  Micro-fractions result and the basic structural integrity of the system are reduced, therefore the system becomes weak and may fail without warning causing damage to the building structure and to personal property.  It is also believed that other factors may also contribute to the failure of PB systems, such as improper installation, but it is virtually impossible to detect installation problems throughout an entire system.  90% of all leaks are at joints in the piping.  Leaks occurring inside a line are almost always on the hot water lines, sometimes in an area of no stress. 

Myth 1:  Only systems with plastic fittings fail.

Systems with metal fittings fail as well. Systems with plastic fittings have more components that fail and our experience shows that they fail at a greater rate.

Myth 2: PB problems occur because of poor installation.

Installation quality may be a factor in PB leaks, but most cases installation does not appear to be the primary cause.  Factors contributing to system leaks include degeneration of piping and/or fittings, water quality, chlorine levels, poor installation and age.  Overtime, some or all of these factors may contribute to system failure.

Myth 3: Inspecting my own pipes is good enough.

Most failures occur in systems that look fine even to the trained eye, so a visual inspection is almost pointless. You should test the water pressure, but that is about all you can do.

Myth 4: This home was built 10 years ago and hasn’t had any leaks, so it must be OK.

In most cases it takes years for PB systems to fail.  While it may leak within a few years of installation, the majority of leaks start in the 10-15 year time frame.

Myth 5: If the pipes do leak, it’s usually minor

How about $100,000 worth of damage from a leak.  80% had some form of structural damage. Frequently, the damage repair entails drywall and some paint. Or maybe carpet pad replacement, but many leaks have been catastrophic causing thousand of dollars to both structure and the contents.

Myth 6: The home inspector said the PB “looked” fine:

It may look fine, but that doesn’t mean much….  most problems with PB systems are not visible. A Home Inspector can look for a leak that is “right now”, he can look for evidence of repairs and/or certain installation mistakes (where pipes are exposed) such as kinks in piping. 

Issues for Property Managers and Multi-Family Owners:

You already know that PB piping is an ongoing maintenance nightmare.  You must deal with reoccurring:

1. Emergency leak repairs
2. Damage to structure and contents
3. Insurance claims
4. Resident complaints
5. Lower levels even if their pipes are replaced, they remain vulnerable to PB leaks from the unit above.
6. Insurance Coverage and Premiums increase
7. Capital reserve adequacy
8. Errors/Omissions liability
9. Mortgage Escrows may require a cash reserve to finance system replacement.

Plumb Plumbing has been re-piping polybutylene homes in the Tucson area for well over 10 years.