Poly “B” Plumbing Pipe – Safe or Not?


Representatives from the Plumbing Industry in British Columbia have indicated in the past that poly “B” piping (older grey plastic piping), is basically ok if kept out of the sunlight and if copper or brass fittings and collars (junctions, T’s and 90 deg. connectors) are used instead of plastic. Poly’B’ plumbing was used somewhere between 1978 and 1995.

I have never seen or heard of a problem in Victoria but there are indications of problems in other areas such as parts of the mainland and in Alberta – possibly due to high clorine content in the water. These cases involved pin holes developing in the pipe itself (deteriorating from the inside out ) and not at the fitting location. This problem seems to have a higher incidence in the proximity of the hot water tank but can happen anywhere. Some Insurance providers will not insure houses for plumbing problems or else at a premium cost, if the house has Poly ‘B’ plumbing.  Others will only insure if copper/brass fittings are currently installed. I have personally seen old pieces of Poly’B’ pipe removed for renovations and found the pipe to still look like new inside.

It is not always easy from an inspection point of view, to tell the type of piping installed, especially in slab on grade houses where the pipes are underground. The main water supply pipe often can be made with this material but does not guarantee that the rest of the house is the same. Damage from leaking during absence or whole house plumbing replacement can be quite expensive. Polybutylene piping is never recommended for boiler piping but likely would have failed by now in the older homes.

People who have this material installed are advised to reduce your hot water tank to 130 deg. and lower water pressure to about 70 psi max.

Pex or similar type plastic piping is put in all new houses now and generally is white or blue and red in colour with brass fittings and collars. All hot water tanks should have at least 18″ of copper piping installed before plastic piping is attached.

Other information links  Jon Eakes   Shell Busey

Information courtesy of Fleetwood Building Inspections


18″ copper installed before plastic piping

Main Water Supply in Poly’B’ connected to copper system. (Electrical system grounding compromised)


Poly’B’ piping with copper fittings


Plastic Poly ‘B’ fittings