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How to Replace Polybutylene Piping with PEX

We share why and how to install PEX plumbing pipes in place of out of code polybutylene pipes.

Ask This Old House plumbing and heating expert Richard Trethewey travels to Richmond, Virginia to help a homeowner replace her polybutylene piping with conventional PEX.

Polybutylene pipes were very popular in the mid-70s because they were easy to make and flexible for use. Over time, it was discovered that the pipe and connections began to fail.

Polybutylene failures can happen inside the wall or can cause more visible leaks. In this video, Richard Trethewey helps a homeowner replace her polybutylene pipes with PEX.

What Can I Use to Replace Polybutylene Pipe?

Because polybutylene pipes are no longer to code they need to be replaced by a licensed professional. In the video above, we replaced polybutylene pipes with PEX plumbing pipes. Richard was assisted by Capital Mechanical.

Is PEX Plumbing Reliable?

PEX tubing is cross-linked polyethylene. Even though they are both plastic, PEX tubing has different properties than polybutylene. PEX is tougher, can withstand heat better, and harder to cut through than polybutylene. It’s been used safely for portable water in the United States for the past two decades.

What Do You Need to Install PEX Tubing?

The tools and materials required to replace the pipes, including the PEX lines, fittings, and the expansion tool, can all be found at home centers and plumbing supply houses. The PEX piping for this project was supplied by Uponor.

How to Install PEX Pipes in 7 Steps

  1. Start by identifying and locating the pipes in the wall. Your contractor should devise ways to remove the pipes while minimally disrupting the space.
  2. Cut access holes where necessary to remove the pipes.
  3. Shut the water off to the house and open all the faucets in the house to remove any water remaining in the pipes.
  4. Cut and remove all the polybutylene piping from the house.
  5. Run new PEX piping through all the locations where the polybutylene used to be.
  6. Connect the pipes using PEX fittings and the expansion tool.
  7. Turn the water back on.

Tools