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The result of common plumbing problems in old homes

Common Plumbing Problems in Older Arizona Homes

 |  Blog, General Home Care, Plumbing

Although they often have undeniable charm and a certain amount of character, older homes come with their own unique challenges. Some of these simply relate to the more significant upkeep homes require as they age, while other issues relate directly to America’s ever-changing building practices. One of the most common is plumbing problems.

While plumbing often presents a challenge in older homes, it is particularly true for houses built between the years 1978 and 1995, when a plastic resin called polybutylene was used to manufacture piping systems. At the time, poly pipes were considered the wave of the future, because the materials were relatively inexpensive and installation was a breeze. Unfortunately, the dream was short-lived, as it only took about a decade for plumbing problems to occur. Why? Because polybutylene proved unable to handle the oxidants commonly found in water supplies. The 1980s witnessed a slew of lawsuits over defective manufacturing and installation, finally resulting in a class action settlement of $950 million.

During polybutylene’s heyday, residential construction exploded throughout the Sunbelt, which includes Arizona. Nobody knows for sure how many of the homes that were built during that time contain polybutylene piping, but estimates put the number somewhere between 6 and 10 million, or around 20 percent of all new homes built between 1980 and 1995.

What’s the Problem with Poly Pipes?

Polybutylene Pipe

Poly pipe issues fall under two main categories. The first is faulty installation, which is nearly impossible to prove, particularly throughout an entire plumbing system. The majority of poly pipe issues, however, are with the actual piping.

Our water supply contains numerous oxidants, including chlorine and chloramines, both of which Arizona water companies use in the water treatment process. These oxidants react badly with polybutylene pipes and their fittings, causing the material to wear down. It then flakes, which causes it to scale and become brittle, leading to micro-fractures and compromising the piping system’s structural integrity.

Unfortunately, all of this occurs inside the pipe (the part that has water flowing through it), meaning that, from the outside, the pipe usually looks fine. The result is that you get very little warning that a plumbing leak lies in your near future. And, if your home has polybutylene piping, you will most likely experience those problems eventually. Typically, poly pipes show evidence of deterioration within about 12 years. This is why many insurers refuse to cover homes with poly piping, which can make selling your home a real challenge.

Where You Find Polybutylene Pipes

You find poly pipes both inside and outside the home. Preferably, you should check both ends of the pipe, since you may find copper at one end and polybutylene at the other.


  • Attached to your main shutoff valve
  • Attached to your water meter (typically located near the street)
  • Entering through the basement, wall, floor, or slab


  • Across the ceiling of an unfinished basement or crawlspace
  • Entering at the water heater
  • Feeding toilets, bathtubs, and sinks

In your interiors, make sure the installer didn’t just use copper stub outs where the pipe exits the wall. Again, you may still have poly pipes, even if you see copper coming out of the wall.

So, what are you looking for, how do you recognize a poly pipe? Typically, exterior pipes are blue, but you also find them in gray and black (this is not the same thing as polyethelene pipes). They usually measure either 1/2″ or 1″ in diameter. Interior pipes are most often gray, but you also see black and blue.

Best Course of Action

If you suspect your home has polybutylene pipes, call a plumber for an inspection. If the plumbing inspection reveals that yes, you have poly pipes, unfortunately, replacing them is the only solution. Eventually, you will develop a leak. Damage depends on how quickly the leak is discovered and the extent of the leak. If you find it quickly, you may avoid widespread damage. However, if you do not, you risk the home sustaining damage from the foundation on up.

Another concern is buying an older home. Standard home inspections do not reveal polybutylene pipes, and no law exists requiring the seller to include this during disclosure. If the home you’re interested in was built between 1978 and 1995, we highly recommend hiring a licensed plumber to inspect the property.

If you have any questions about your plumbing, or the plumbing in a home you’re looking to buy, talk to Isley’s Home Service. Our team of plumbing experts is available 24/7. Or, send your question to Ask Johnny D – he’s always happy to help.

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