Exterior-Polybutylene underground water mains are usually blue(13), but may be gray(14) or even black(15) (this not to be confused with black poly -polyethelene pipe). It is mainly 1/2" or 1" in diameter, and it could be found entering your home through the basement, floor, concrete slab or through your crawlspace.  Common areas is that it enters the home near the water heater. Your main shutoff valve is usually attached to the end of the water main. You should check at the water meter (Usually located at the street) near the city water main.

Interior- Polybutylene used inside your home can be found near the water heater, running across the ceiling in unfinished basements, and coming out of the walls to feed sinks and toilets.

Warning: In some part of the country plumbers will use copper "stub outs" where the pipe exits a wall to feed a fixture. 

I have found the best place to identify if the home has polybutylene is at the water heater.

Will the Pipes Fail? Some experts say its not a question of if they will fail, rather a question of when they will fail.

While scientific evidence is hard to come by, it is believed that certain chemical reactions to oxidants in the public water supplies, such as chlorine, react with the polybutylene piping and acetyl fittings causing them to become brittle. Micro-fractures may result, and the basic structural integrity of the system is reduced. The system becomes weak and may fail without warning causing damage to the building structure and personal property. It is believed that other factors may also contribute to the failure of polybutylene systems, such as improper installation, but it is virtually impossible to detect installation problems throughout an entire system.

Throughout the 1980's lawsuits were filed complaining of allegedly defective manufacturing and defective installation causing hundreds of millions of dollars in damages. Although the manufacturers have never admitted that poly is defective, they have agreed to fund the Class Action settlement with an initial and minimum amount of $950 million. 

I have found that most of the settlement has already been paid out. You may have to contact the settlement claim company to find out if you eligible under this settlement. 

Polybutylene systems with metal (usually aluminum or copper) fittings do not fail as often as polybutylene systems with plastic fittings. There is a disagreement with plumbers that polybutylene or its fittings are a problem. Polybutylene lines may be susceptible to leakage from sudden splitting due to fluoride and chlorine found in municiple drinking water. Polybutylene plumbing systems with metal (usually aluminum or copper) fittings do not fail as often as polybutylene systems with plastic fittings.

 It is my experience unless the system is leaking we will not be able to identify if or where failures may occur.

Small leaks are the most problematic because much of the damage is done before  leak symptoms are visible.  

For homeowners it may be advisable to replace this type of piping with an alternate material.

Wenatchee and Chelan Home Inspections -Polybutylene Piping

When looking for home Inspections in Wenatchee, East Wenatchee, and Chelan contact-

NCW Home Inspections LLC