Polybutylene Plumbing

polybutylene plumbing alpharettaPolybutylene is a type of plastic resin. Shell Oil Company was the sole manufacturer of polybutylene resin used for plumbing applications. This material was used in the manufacture of interior and exterior water supply piping from 1978 until 1995. It is found most commonly in the South and was installed frequently in the Atlanta market. Estimates say that one out of every five homes built during these years has polybutylene plumbing. The polybutylene piping was used for two different applications in residential construction.

  1. Exterior main water service lines connecting the home to the street
  2. Interior plumbing systems

The interior and exterior piping material are independent of each other. Homes that have copper plumbing or PVC inside may have a main water service line made of polybutylene. While other homes may have a copper or PVC main line and have polybutylene piping inside, although this combination is less common than the former. Copper and PVC piping are the other materials that are used most frequently in our market. Copper is the most common and is often considered a superior product.


  • Low cost materials for economical plumbing system
  • Easy to install
  • Quiet plumbing system
  • Functions well in cold temperatures

Potential Problems

Soon after polybutylene piping was used in residential homes, homeowners began reporting problems. The issue did not receive much attention until 1980, when lawsuits began to be filed.

While not proved conclusively, it is believed that chemicals found in the water supply, such as chlorine, react with the polybutylene piping and/or the acetate fittings causing them to become brittle. The plumbing system becomes weak and can fail without warning, causing damage to the home and personal property.

Determining If A Home Has Polybutylene Plumbing

There are several ways to determine if a house you are interested in buying has polybutylene plumbing systems. Class action lawsuits have been settled on this issue, a fact you should know if you own a house with this type of plumbing or if you are considering purchase of a home with this type of plumbing.

The home inspector should be able to identify polybutylene plumbing in a house that has captured your interest. You may also check the answer to question 7(h) on the Seller’s Property Disclosure Statement.

Often a visual check of the plumbing under the sinks will help determine the type of plumbing materials used. However, you should be aware that copper is sometimes used under the sinks and is then connected to polybutylene out of eyesight. The plumbing material in a home with an unfinished basement or a basement with a drop ceiling is easy to identify.

Occasionally the inspector will be unable to determine the material used for the main service line, since it is buried in the yard. A narrow trail or visible depression in the grass leading from the water meter may indicate that the line has been replaced. You may also want to notice other yards in the neighborhood, or talk with the neighbors. If neighbors have had replacement then the odds are that there was (or is) a polybutylene main service line to the home you are considering.

Polybutylene Piping Warning Signs

Lets take a quick look at the exterior and interior systems:

Exterior System:

The polybutylene exterior main water service line is a single pipe usually blue in color (although occasionally it is black or grey). It connects the main line in the street to the home plumbing system. There are warning signs when an exterior system fails and cost estimates on repairs.

When the exterior system fails:

  • Lower water pressure
  • Soggy area in the yard between the water meter and where the line enters your home
  • Visible surface water runoff or higher than expected water bills (although this can also indicate a malfunctioning and continually running toilet)

The replacement cost for an exterior system that has failed for a typical home is between $1000 and $1500 dollars for PVC and $200 more if you replace it with a copper line.

Interior System:

The interior polybutylene plumbing system consists of piping and fittings. The fittings are attached to the piping using two different methods. The most common connection method is crimping a copper or aluminum band around the pipe at the joint. Less common are threaded compression fittings. While the piping is made of polybutylene, the fittings are usually acetate or copper. There are warning signs when an interior system fails and cost estimates on repairs.

When the interior system fails, you may see:

  • Water spots on walls, damp ceilings or puddles in the floor, depending on the location of the leak
  • Substantial damage to the home if the leak is large and it is not shut off quickly
  • Damage and/or loss of personal property if the leak delivers a great deal of water into the interior of the home

It is obvious when this system fails and springs a leak. It is critical to immediately turn off the main water valve any time you see indications of a water leak.

The replacement costs for an interior system can be high, especially if structural and personal property damage is involved as the result of a leak. The replacement of piping inside your walls is a large and messy undertaking. The typical cost to change the polybutylene piping to copper piping in a home with two full baths is $4500 to $5000. Add about $900 per extra bathroom. These cost include the repair and repainting of the walls and sheetrock necessarily damaged to gain access to the plumbing, but does not include water damage to other areas, or replacement of personal property damaged in a leak situation.

Jeff’s Note: Locate the main shut off for all utilities (water, electric, gas, etc.) before you have a situation where you need that information.


Unfortunately, there is no way to maintain and prevent this plumbing from failing. There is no test that can determine how long you may have until the plumbing fails. Polybutylene plumbing is not guaranteed to fail, but it is the least reliable system on the market and does have a significantly higher incidence of problems than other options.

Class Action Lawsuits

As a result of problems with this type of plumbing, there have been two class action lawsuits already settled in this matter which may be of interest to anyone who owns or is considering ownership of a home with this type of plumbing:

Spencer vs. DuPont – Under this settlement, Dupont will pay 10% of the replacement costs and 10% of the damaged caused by leaks. This money is payable for qualified leaks if the replacement is made within 15 years of installation. This settlement is generally for interior plumbing with acetate fittings.

Cox vs. Shell Oil – Under this settlement, Shell Oil will pay for 100% of the cost for qualified replacement. Qualifying yard service replacement occurs if there is a leak within ten years from the date of installation. To qualify for interior plumbing replacement, two leaks must occur within 13 years from the date of installation for Acetal insert fittings and 16 years for metal insert fittings.

The Home You Love Has Polybutylene Plumbing — Now What?

First, you must take into account that a home with polybutylene plumbing will sell for $4,000 – $5,000 less than a home with copper plumbing with all other things being equal. Ask your REALTOR® to help you determine a fair offer based upon sales from the neighborhood that likely have the same polybutylene plumbing.Do not depend on winning any potential damage claims from the class action lawsuits to compensate you. If you win a damage claim, great, but you need to purchase assuming that you and you alone will be responsible for any corrective action required after completion of the sale.

Jeff’s Note: Enjoy peace of mind, while reducing the risk of damage to your home and personal property, by replacing the plumbing immediately after purchasing the home. Do not wait for it to fail. On the positive side, you will recover most of the expense when you sell the home.