Was Your Townhouse Built Before 1996? Check for Poly-B Plumbing

 If your townhouse was built before 1996, it may contain Poly-B water-supply piping.

Poly-B, short for polybutylene, was commonly installed in Canadian houses, townhouses, and some condominiums from approximately 1978 through the mid-1990s. In 2026, buildings from this period are roughly 31 to 48 years old.

However, the age of a building is only the first clue. Not every older townhouse has Poly-B. Some were originally built with copper piping, while others may already have been partially or completely repiped with PEX.

As a Red Seal plumber working in BC, I recommend starting with a careful visual inspection of exposed water-supply lines. You do not need to open walls, disconnect fittings, or move the pipes just to look for identifying features.

Watch the video below to see where to look and how Poly-B differs from copper and PEX.

What Is Poly-B Plumbing?

Poly-B is a flexible plastic pipe that was previously used for hot and cold water distribution. It became popular because it was lightweight, flexible, relatively inexpensive, and easier to install than rigid copper piping.

Most Poly-B found in Canadian homes is grey, but colour alone is not enough to identify it. Other pipe materials, including some types of PEX, can also appear grey.

How to Identify Poly-B Piping

Look for printed factory markings along the side of the pipe. Common Poly-B markings include:

• PB2110
• CSA-B 137.8

If you can clearly see one of these markings, the pipe is likely Poly-B.

However, the absence of a visible marking does not automatically prove that the pipe is not Poly-B. The printing may be facing the wall, covered, faded, or located on a concealed section.

Do not pull, twist, bend, or cut an older pipe to find the marking. If identification is uncertain, take clear photographs and have the piping checked by a qualified plumber.

Where Should You Check?

1. Under Kitchen and Bathroom Sinks

Open the cabinet and look at the water-supply pipes coming through the wall or cabinet floor.

In many installations, the water-supply pipe connects to a shut-off valve. A braided faucet supply hose then connects from the shut-off valve to the faucet.

Do not confuse these water-supply pipes with the sink drain. A black ABS pipe and P-trap located beneath the sink are part of the drainage system. They are not Poly-B water pipes.

2. Laundry and Mechanical Rooms

Check visible piping near the washing machine, mechanical room, access panels, and water heater.

A Poly-B system may transition to copper or another approved material near the water heater. Seeing copper directly above the water heater does not necessarily mean the entire townhouse has copper plumbing. Grey Poly-B may still be present farther away from the tank or behind a wall.

Do not move insulation, remove access panels that are not designed to be opened, or disturb older piping during a basic visual inspection.

3. Unfinished Basements and Utility Areas

If your townhouse has an unfinished basement, suspended ceiling, crawlspace, or accessible utility area, look for exposed waterlines.

Follow the visible pipes only as far as you can safely see them. A townhouse may contain more than one pipe material if only part of the original plumbing system was replaced.

Poly-B, Copper, and PEX Are Different

Poly-B

Poly-B is usually a grey flexible plastic water-supply pipe. It may display PB2110 or CSA-B 137.8 markings.

Copper

Copper is a rigid metallic pipe. New copper normally has a bright reddish-brown appearance, while older copper may develop a darker colour or surface patina.

PEX

PEX is a flexible modern water-supply pipe. It may be red, blue, white, or grey and normally has PEX-related information printed along the tubing.

Red PEX is commonly used to identify hot-water lines, and blue PEX is commonly used for cold-water lines. However, colour is an installation aid and should not be the only method used to identify a pipe.

Why Is Poly-B No Longer Used?

Poly-B piping became associated with fitting failures, pipe deterioration, and concealed water leaks.

Several conditions may contribute to deterioration, including heat, water pressure, installation methods, and long-term exposure to chemicals found in treated water.

Some deterioration can begin inside the pipe. This means a Poly-B pipe may appear normal from the outside even though its internal condition cannot be confirmed visually.

A visual inspection can help identify the pipe material and obvious signs of leakage, staining, previous repairs, or damaged fittings. However, it cannot confirm the condition of every concealed section of the plumbing system.

Poly-B production for North American residential plumbing was discontinued, and it is no longer used for new residential water-supply installations.

Does Finding Poly-B Mean Your Home Is Leaking?

No. Finding Poly-B does not mean that an active leak is happening right now.

It means you should identify how much Poly-B may still be installed, document what you can see, and obtain a professional assessment before deciding on the next step.

Do not assume that every Poly-B system is currently leaking. At the same time, do not assume that a pipe is in good condition only because the exposed surface looks normal.

What Should You Do If You Find Poly-B?

1. Take Clear Photographs

Photograph the pipe colour, printed markings, visible fittings, shut-off valves, and the surrounding area.

Try to take one wider photograph showing the pipe location and one close-up photograph showing the printed marking.

2. Check Renovation Records

Review previous plumbing invoices, inspection reports, renovation documents, and property records.

A previous owner may have replaced some or all of the original Poly-B piping. One visible section of copper or PEX does not automatically prove that the entire townhouse was repiped.

3. Arrange a Plumbing Inspection

A qualified plumber can help identify the pipe material, examine accessible fittings, look for evidence of previous repairs, and determine where Poly-B may still be present.

The plumber can then explain whether monitoring, further investigation, partial replacement, or complete repiping should be considered.

4. Review Your Strata Information

In a townhouse complex, responsibility for plumbing may depend on the location of the pipe and the strata bylaws.

Some piping may serve only one unit, while other piping may be part of common property. Review the strata documents and contact the property manager before arranging work that could affect walls, ceilings, or shared plumbing.

5. Contact Your Insurance Provider

Insurance requirements vary between companies and individual policies.

Finding Poly-B does not mean that insurance will automatically be cancelled or denied. Ask your insurance provider or broker directly whether Poly-B affects your coverage, premium, deductible, inspection requirements, or replacement conditions.

What Homeowners Should Avoid

• Do not bend or pull an older pipe to read the printing.
• Do not cut into walls or ceilings simply to search for Poly-B.
• Do not assume every grey pipe is Poly-B.
• Do not mistake a black ABS drainpipe for a water-supply pipe.
• Do not assume one short section of PEX or copper means the entire home was repiped.
• Do not attempt to disconnect an older fitting just to identify the pipe.
• Do not ignore staining, moisture, corrosion, or evidence of previous repairs.

If an active leak is present, close the appropriate water shut-off valve if it is safe to do so. Contact a qualified plumber and notify the strata or property manager when required.

Frequently Asked Questions

Does every townhouse built before 1996 have Poly-B?

No. The construction year only indicates that Poly-B may have been used. Some townhouses were built with copper, and others have since been partially or completely repiped with PEX.

Is Every Grey Water Pipe Poly-B?

No. Some PEX and other piping materials can also be grey. Check the printed markings and fittings, and obtain professional confirmation when identification is uncertain.

Can I Determine the Condition of Poly-B by Looking at It?

You may see obvious leakage, staining, damaged fittings, or previous repairs. However, a pipe that looks normal from the outside may still require further assessment because concealed sections and the inside of the pipe are not visible.

Does Poly-B Have to Be Replaced Immediately?

Not necessarily as an emergency when there is no active leak. However, the system should be properly assessed.

The scope and timing of any replacement plan depend on the installation, accessibility, condition, renovation history, strata requirements, and insurance considerations.

Final Thoughts

If your townhouse was built or renovated between the late 1970s and the mid-1990s, begin by checking accessible water-supply pipes under sinks and in utility areas.

Look for PB2110 or CSA-B 137.8 markings, but remember that colour alone is not enough.

Identify it early, document what you find, and obtain professional guidance before a leak occurs.

This article provides general homeowner information and is not a substitute for an on-site plumbing inspection, insurance advice, or interpretation of strata bylaws.