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Water pipes

 

Non Traditional
Water Pipes

(September 2010)


Prior to the 1950’s, a lot of residential potable water pipes were galvanized steel pipes with threaded fittings. These pipes tended to last 30 - 50 years and failed mostly at the fittings and due to interior build-up of rust. Similar non-galvanized steel pipes were used in hot water (or “hydronic”) heating systems and these pipes are considered to have life cycle expectancies of 50 - 70 years.

After the 1950’s, copper water pipes became the standard for both potable water and hydronic heating systems. Over the years it became evident that the acid water conditions in the Lower Mainland of BC would slowly corrode the copper. The pipes develop small pinhole leaks but since these leaks do not release much water they can go undetected for years. In general, the life expectancy of copper water pipes in single family residential construction appears to be 40 - 50 years in the Greater Vancuver area. Copper water distribution pipes used in hydronic heating systems are not showing signs of premature failures.

Beginning in the 1980’s, a grey plastic “polybutylene” pipe was often used. There were early failures when these pipes were connected to each other with plastic fittings. The writer is aware of proposed court settlements as a result of a class action lawsuit. More information can be obtained at www.pbsettlement.ca. To this date, we are not aware of generalized problems in the Lower Mainland of BC with the polybutylene pipes when used with copper fittings in potable water systems. There have been problems with these pipes when used in heating applications.

Since the late 1990’s, the plastic pipe installed in residential water systems has been cross-linked polyethylene or “PEX”. This “stabilized” polyethylene is reported to have improved strength and greater stability and the pipe is installed with copper fittings.

The first reports of PEX pipe problems in the USA began to circulate in 2007. The problems appear to be related to high concentrations of residual chlorine in the water affecting both the plastic pipe material and certain fittings. As of 2010, there was not much available information on the causes of failure.

We have general reservations about the long term performance of non-metallic pipes when they are used in heating applications. One general characteristic of plastics is their susceptibility to material breakdown at elevated temperatures after extended periods of time. The PEX pipes are probably more stable than the polybutylene pipes they have replaced but they have not been in use in our area for very long.

In September 2002, we witnessed the general failure of Heatway Entron 2 pipe used in a hydronic baseboard heating system only 11 years old. This pipe had impressive performance specifications and was rated for continuous use at 180°F by the manufacturer. The pipe became brittle regardless and began to leak.

In summary, we regard all plastic pipes, especially those used in heating applications, with some degree of skepticism. We cannot assure you, our clients, that we can predict or even be the first to become aware of the latest product disaster. Private home inspectors cannot be responsible for the reliability of the pipes nor for being able to project the longevity of the products. In time, we may be able to inform you on their reliability but obviously not in the near future.


DISCLAIMER: Please note that the information and materials located on our web site is provided free, for general information only, and is not intended to provide or be relied upon as specific professional advice. This information represents the current technical facts as understood at the time published, but is in no way comprehensive and you should not act or rely on it regarding your specific situation -- until you have consulted with a qualified home inspector. No liability is accepted therefore for any errors or losses that may be incurred if it is relied on "as is". The use of information posted on these pages does not create a consultant-client relationship.