Plastic drainage systems have been commonly used for many years. Only more recently, though, has plastic become common as a water supply pipe in many areas. There are several types that may be encountered including polyvinyl chloride (PVC), chlorinated-polyvinyl chloride (CPVC), polybutylene (PB) and crossed linked polyethylene (PEX).  PVC and CPVC use a solvent to join sections and fittings. PB and PEX use specially developed fittings and clamps.

Considerations
In the past, there was some hesitancy in using plastic water pipes because of concerns over contamination from leaching of the plastic compounds. This has not proven to be a serious concern and, in fact, all these pipes have been approved for use in potable water systems. The HouseMaster Technical Staff reports that there have however, been some problems with individual lots of piping because of the use of improper resins. There have also been some major concerns with PB piping as the components in some installations have deteriorated. PB leakage has also occurred due to improper installation procedures – especially on hot water lines where the thermal expansion rate increased the chance of failure.

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