Polybutylene Water Pipes in Arizona

When searching for a house, I was given a piece of advice by a grandfather:  “Don’t buy a house with polybutylene plumbing.”  Well it may not be that bad, but if you’re new to Arizona, you may not know about the “dreaded” grey water supply line called polybutylene (also called “poly” or “PB”) developed in the 1970’s and marketed as “the pipe of the future.”

PB is, or was, flexible, easy-to-cut gray plastic pipe put together with simple crimp connectors, used in approximately six million homes in the U.S.  It was widely used in the Sunbelt until 1996 as a substitute for copper because it was less expensive, and it could be installed quickly by semi-skilled labor. It is unclear how many homes in Arizona have PB, but an estimated 80,000 Arizonans have had problems with it.

Why should you care?  Part of your water system may be installed under pressure in the ceiling, where a leak can be catastrophic.  Wherever it is, the onset of a poly problem is sudden and unexpected to most homeowners. As a plumber describes it, “First you hear a bang, then there’s a sudden drop in water pressure. Water then starts coming from pipes you didn’t know existed,  If a pipe has been leaking for some time without the homeowner’s knowledge, severe structural damage to the home can make repairs extremely difficult.

You should also know that,  according to the Arizona Water Resource at the University of Arizona, “In some cases, homeowners are finding that homeowners insurance companies will either cancel their coverage when extensive damage is caused by polybutylene or refuse coverage to homes piped with PB.”   In addition, homes with poly often take longer to sell, and sell for less.

The problem that no one forsaw, is that, in addition to the difficulty in making tight joints, the pipe itself deteriorates over time primarily from exposure to the chlorine in the water supply. Sunlight, solvents, cutting oils, solder flux and pipe dope are also known enemies of polybutylene. Poly pipe generally takes 10-15 years to begin to show signs of severe deterioration. Although some poly piping problems stem from improper installation of the fittings, most complaints are with the integrity of the piping itself.   Even if you know you have poly pipes, you still can’t tell what condition they’re in just by looking at or squeezing them, because the harmful oxidants are carried in the water, and the pipe deteriorates from the inside.

The fitting pictured here was still holding up despite the internal decay and flaking. It looked fine on the outside, but fortunately the homeowner decided to replace the poly system before the problems started.   This is not an IF, it is a WHEN.

Poly pipe exists in Tucson neighborhoods built between the late 70’s and 1996.  In 1995, PB was banned for use in residential building, however plumbing companies were allowed to use up their supply of PB, and we still see it in some 1996 homes.  There was never a federal ban on the piping, but in 1996 Shell Oil Company stopped selling the resin that manufacturers used to make the defective pipes.

Poly can be replaced and there are local plumbing companies that specialize in this work.  Is it expensive? Yes. If the home you’re considering still has polybutylene plumbing, you will want to build the cost of re-plumbing into your purchase or repair budget.  Some lender-owned properties have had their poly replaced in preparation for resale, but never make assumptions just because there is wallboard missing in some areas. Most lender-owned properties are sold as-is and come without disclosures.

Learn to identify poly to protect yourself, or be certain that the home inspector you hire can identify it.  One caveat, though: some builders disguised its presence. They placed poly in the walls, then connected it to copper stubs for the plumbing fixtures outside the walls to make visible plumbing look higher quality, and more “professional.”  When the walls went up, the house appeared to be piped entirely in copper. This system of piping confounds many homeowners, real estate agents, and even home inspectors. Identify polybutylene by its color and size: Blue, gray and black pipes in ½” to 1” diameters is common.

Identify polybutylene by its color and size: Blue, gray and black pipes in ½” to 1” diameters is common.

  • Blue pipes were used outdoors for primarily cold water
  • Gray and black were used interchangeably both outdoor and indoor.

Identify polybutylene by the stamping on the flexible plastic material.

  • Much of it was manufactured by Qest.
  • It may also say ASTM with a series of numbers.
  • Polybutylene pipes’ most common imprint was PB2110.

 Locate areas where polybutylene pipes were most often used.

  • Outdoors near the main water shut-off valve, at the water meter and entering the home through the basement, concrete slab or crawl space, most often entering near the water heater.  Often a copper pipe at a water meter will be attached to poly pipe somewhere underground, so it is wise to check both ends of the pipe. If the incoming pipe is a light blue plastic pipe, it is likely that you have a type of poly pipe informally called “Big Blue”. This pipe is extremely prone to failure and unexpected bursting. If you have this type of pipe as an incoming water supply line, it is recommended that you have it replaced as soon as possible.
  • Indoors, remove panels under sinks and behind showers, tubs and toilets to expose the plumbing pipes. Are there copper or galvanized steel pipe and fittings from the wall to a plumbing fixture, connected to poly pipes behind the walls? Many properties have a combination of copper and poly pipes.
  • Look for copper, aluminum or brass crimp fittings used to link pieces of polybutylene pipes to plumbing joints and fittings. Acetal fittings, a plastic resin often gray or white in color, were also used.  If you see copper fittings on a pipe, it does not indicate that you do not have poly piping; the presence of these copper pipe fittings increases the likelihood that non-copper plumbing pipes are polybutylene.

Caution:  Not all “plastic” pipes are PB (poly).   If you do see plastic, it may be PEX, a perfectly suitable alternative for re-plumbing, which is less expensive than copper, especially since PEX is flexible and well adapted for temperatures below freezing all the way up to 200° F.

So you have poly, now what?  During the inspection period (the first 10 days following acceptance of your offer), in addition to a full home inspection, get repair bids from one or more qualified poly replacement companies.  Replacement entails abandoning all poly pipes and installing a new system. It’s not difficult, but it involves cutting some holes in the wallboard to gain access. Some companies include patching and repainting the walls, others just do the re-plumbing and leave the patching and painting to you, so be sure you know what is included in the bid.  If there has already been damage to your home from a poly pipe leak, then the cost of re-piping and repairing your home will increase considerably.

The cost of replacement varies quite a bit from plumbing company to company, and with the quantity of water fixtures the house has.   Average costs for PB-related home repairs are about $4,000, says Carl Triphahn of the Piping Industry Progress Education Trust, a contractor’s organization in Phoenix.  Although replacement can be done at any time, it’s easier and less expensive if you replace it while the house is vacant.

If you know from the beginning there is poly in the home, you can include this repair in the terms of the purchase contract. If not, then it can be negotiated during the inspection period, as in “Seller to replace polybutylene plumbing…”  The selling price may be adjusted for this, or not, and the cost wrapped into the mortgage amount.

Unlike most other home maintenance issues, delaying poly replacement may have devastating consequences. While pipe replacement is a “hidden” investment, it will increase the value of your home, unlike many other home improvements.

If you have any other questions, you can contact Tammy and she will work to find the answers for you. Call Tammy at 520-201-0603 or at tammy@tammywolf.com.