Poly-B Piping: Why You Ought To Be Concerned

We get a lot of calls about plumbing problems with polybutylene pipe (“Poly-B”). We’ve written about this stuff before; it has a tendency to develop leaks, and insurance companies sure don’t like it! One might wonder why there’s so much of this grey tubing installed in Calgary. Since we’ve been plumbing here since 1972, we thought we’d give you some background.

Copper: Good, But Expensive

Most Calgary homes were originally built with copper pipe, but copper has always been relatively expensive. It’s very useful, because it can be made into a wide variety of shapes and it conducts heat and electricity very well. It’s also a very safe and durable plumbing material. At the same time, it’s scarce because there are comparatively few places where it can be mined, and it’s difficult to refine. Copper began to climb in value in the 1970s due to accelerated global demand and continuing limited supply. Naturally, every industry that uses copper has seen pressure to find less costly alternatives.

Remember aluminum electrical wiring back in the 1970s? (No? Then let Granddad tell you a story.) At the time, it seemed like a good cost saving alternative to copper wiring, but eventually it was shown that electrical connections would degrade more quickly due to aluminum’s differing properties, like higher resistance and thermal expansion, and non-conductive oxidation. These properties over time led to loose connections and overheating, sometimes to the point of fire hazard. So, these days if you buy a house that was built in 1972 and still has its original wiring, chances are you’re going to be upgrading it for safety’s sake, and your insurance company may insist on this.

Poly-B: Less Expensive, BUT…

There’s a similar crisis in the residential plumbing industry. Polybutylene is a plastic resin that was introduced to the manufacture of water supply piping around 1978, and remained in common use well into the mid 1990s. Poly-B pipe is practically everywhere– about a quarter of Calgary homes have it– it was widely implemented by builders as a less expensive, more flexible option to copper all over the industry, and it was easy to install.

Sadly, time has shown that Poly-B is not adequate for high pressure and temperature combinations. It may have been cheaper, but its total life expectancy is much shorter than copper. The majority of leaks begin to occur in the 10 to 15 year time frame.

Why The Leaks Occur

There are several factors contributing to system leaks. Polybutylene is vulnerable to ultraviolet light. Unaware of this fact, many builders frequently stored spools of the tubing outdoors, causing the resin to photodegrade prior to installation.

Poly-B pipe is designed for less than 70 pounds pressure (some up to 100–105). However, if 70 pounds is your average water pressure, you’ll have to allow for spikes in pressure that far exceed that value, especially if you’re in the habit of turning your taps off so suddenly that you hear a bang or thud. When you do this, remember there’s a column of incompressible water in motion suddenly coming to a dead halt; all that kinetic energy has to go somewhere… The end result is akin to hitting the pipe with a hammer. Areas where the tubing takes sharp turns will also exacerbate these pressure spikes. We can help you with pressure reducing valves that will minimize this risk.

Excessive water temperature will also weaken the plastic over time, just as chlorine, chloramine and other oxidant chemicals used in water treatment will contribute to brittleness. Often, cheap plastic fittings were used and these will also become brittle eventually.

Do You Feel Lucky?

In effect, homeowners with Poly-B plumbing are taking a real gamble. Even with perfect installation and metal fittings, polybutylene systems will eventually fail at some point. Over the years the stress takes its toll, and fatigue sets in on the plastic. Worst case scenario is a pipe bursting along its longitudinal seam, while the best case is the development of isolated pinhole leaks. When the pipes do leak, it is usually minor– but catastrophic failures can and do occur.

If your home has Poly-B piping and you have not experienced any leaks, it would still be prudent to have your system visually inspected to ensure your fittings are in good shape, and to check the water pressure and temperature settings to be sure they are well within the material’s design limits.

PEX: A Smart, Affordable Alternative

Selling your home may force your hand– some insurers may insist that the polybutylene tubing be replaced. Doing so with copper might be prohibitively expensive, but fortunately, we can recommend another flexible tubing option that is far more durable and resistant to pressure and temperature: PEX.  That’s the trade name for Cross-Linked Polyethylene, and it’s quickly becoming the dominant technology for carrying water into homes and businesses. It’s been in use in Europe since the 1960s.

The cost to replace all your Poly-B with PEX is typically $5,000 – $10,000 and takes two to three days. It’s an expense compared to having your windows replaced. If you do it preventively though, before any leaks occur, you’ll be avoiding potential water damage costs that can be so much higher.

If you’d like us to come out to check the condition of your Poly-B plumbing, give our Calgary Plumbers a call, we’re available 24/7/365.