What is Poly B plumbing?

Poly B, is a flexible grey pipe used in residential plumbing and hot water heating systems from the mid-70s through the 80s and into the mid-90s.  Unconfirmed estimates say there are approximately 200,000 homes in BC with Poly B water systems and some 700,000 homes across Canada. Poly B pipe can be identified through it’s characteristic light grey colour and labeling of: PB 2110 in the permanent text on the side of the pipe. Poly B was designed to be a substitute for copper supply piping. The demand for Poly B was driven by rising copper prices making the pricing of Poly B attractive. Poly B was also chosen because it was less labour intensive to install than copper. In Canada, Poly B was originally tested and certified by the Canadian Standards Association (CSA) as an acceptable product for potable water systems but it was removed from the National Plumbing Code as of 2005. The reliability and use of Poly B has been the subject of debate. Although the system has performed as designed and intended in many homes, Poly B has experienced failures impacting the way insurance companies may view homes that have these pipes installed.

Any plumbing supply system can fail

All plumbing systems may fail without warning and cause damage. Even copper pipes have a lifespan (approximately 50 years) and all systems can fail if poorly installed or are installed in adverse conditions (recirculating copper supply systems in condo buildings, for example, are failing sometimes in less than 20 years-leading to expensive re-piping jobs). Factors that may contribute to Poly B failure include:

  • The use of plastic fittings to connect the pipe rather than metal ones
  • Over crimping of aluminum bands that result in hairline cracks in the fittings
  • Poor installation near heat sources and hot water tanks, and in areas of excessively high temperatures
  • Improper installation causing stressed piping (curves too tight)
  • Applications where relatively high levels of free chlorine are used
  • Houses with high water pressure

Canada Vs. USA

The majority of Poly B failures seem to be in the United States. The Canadian experience with Poly B has been much different. Many U.S. failures occurred in southern areas where plumbing was run in attics (a practice not used in Canada) where the piping can be literally baked by excessive heat and in areas with excess chlorine or chemical content. For the most part, houses in BC had their Poly-B piping installed correctly using copper or brass metal insert fittings and soft copper crimping rings, not the plastic insert fittings (which are reported to be more susceptible to failure). However, there are houses in BC that used the plastic elbows and pipe joints. In addition, some authorities speak of not just failure of the joints but also of the pipes itself.

Poly B in heating systems

Poly B is a significant concern where it has been used with in floor radiant heating systems. Normally the water in the heating system becomes de-oxygenized within about the first year after installation. Poly B pipe allows oxygen to cross from the surrounding air into the water in the heating system (unlike other types of piping).   The oxygenated water can cause pre-mature rusting of the heat exchanger in the system and early failure of the boiler.

Poly B lawsuits

There were several class action lawsuits against the manufactures in the early 2000’s but it does not appear that any of these are still current and available to a home buyer as an avenue for funding to repair or replace poly B in their home.

What can a homeowner do? 

The only way to ensure there are no poly B failures is complete replacement of all the piping. However, it may be possible to extend the life of poly B piping by doing the following: 

  • Change plastic fittings: if your Poly-B fittings are plastic, consult a plumber regarding replacing them with copper or brass ones.  
  • Don't over-crimp: Metal bands are used to hold pipes in place. Hairline fractures causing leaks can result from bands that are crimped too tightly. 
  • Lower the chlorine: If you live in an area that has high levels of chlorine, install a filter to remove chlorine from your home.
  • Lower your water temperature: BC Hydro recommends a temperature no lower than 55 degrees Celsius. Anything lower than this may allow bacteria to grow in your hot water tank. 
  • Ensure plastic piping (of any kind) is not within 18 inches of your hot water tank or any other heat source such as a flue vent or chimney.
  • Lower your water pressure: Most home inspectors recommend that water pressure be kept between 40 and 60 psi. 

Poly B and buying a house

Many homes have Poly B in them and have not experienced any problems. However, insurance companies do take note of the failures that have happened and this has affected the insurance they may offer to homeowners who have Poly B in their houses. If your home was built between the early 1970's and early 1990's, the insurance company will want to know what type of plumbing is in the home. Insurance companies may be reluctant to provide coverage on homes with Poly-B plumbing as losses from ruptures can be massive. It is possible that a buyer will not be able to obtain insurance at all for a home with Poly-B or that the premiums and water damage deductible will be much higher. 

Response from local insurance companies:

I polled a few local insurance agencies and there are options available for homes with Poly B. Almost all companies that I spoke to will insure a home with Poly B albeit with different conditions around work required and/or deductible due should there be a failure of the Poly B. The best thing to do is have a conversation with your insurance company up front (prior to subject removal) so there are no nasty surprises should a leak occur.

Cost for replacing Poly B

Unfortunately, there is no easy answer to this question. Each home is different in size and scope as well as access to the pipe in question. Buyers should get at least three estimates from reliable companies to ensure they are getting the best value when considering re-piping of a house

Posted by Jay McDouall on
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