PEX Tubing Installation: Do's and Don'ts

PEX tubing is chemically treated high-density polyethylene that's flexible, heat resistant, and doesn't develop pinholes or corrode. Many do-it-yourselfers are transitioning to PEX from copper pipes since installation doesn't require welding or chemicals to join the tubing together.

Also, fewer fittings or connections are required making these types of plumbing pipes much faster to install than metal or traditional rigid plastic. To make the installation process go as smoothly as possible, it's important to remember these dos and don'ts.

Don't Turn Off the Water to the Entire House

Turn off the water before you begin work, but don't turn off the water to the entire house if this isn't necessary. Most homes have valves that allow you to turn off water from one area at a time. After you do this, drain water from the pipes you want to replace by turning on both the hot and cold taps of the lowest faucet in the area you'll be working.

Do Keep Piping Away From Extreme Temperatures

When positioning the piping during PEX tubing installation, make sure you keep it away from areas where it could be exposed to extreme temperatures. Do not install on outside walls, crawl spaces, or attics. Only install the tubing in these areas if the pipes are insulated according to local plumbing codes. The tubing needs to be 12 inches away from recessed lighting and three inches away from gas vents.

It also shouldn't be used in direct sunlight or for gas lines.

Don't Cut Tubing to Exact Size

Doing this doesn't allow for mistakes and could make the PEX tubing installation take longer than it should or cost you money because you'll need to buy new tubing. When cutting the beginning and the end of the tube, leave a little extra to reduce the chance of the piece being too short which would make connection to manifolds impossible.

Do Identify Tubing Runs

Do mark each run at the manifold with a piece of thick paper and a plastic fastener around the pipe. Write on the paper with a black marker to identify where the water from the run goes, such as the bathroom sink, hot or cold water, or the basement toilet.

Don't Bend PEX Tube Too Tightly

PEX tubing can be bent slightly to accommodate curves. But do not bend the tubing tighter than a radius that's six times the size of the tube. For example, a 1/2-inch tube can have a three inch bend radius. All 90-degree turns should have bend supports.

Do Know How Deep to Drill or Notch

With PEX tubing installation, drill to a maximum depth of 40 percent the depth of the wood on load bearing wood- and i-joists. Notches can go to a 25 percent depth. A non load bearing wood- or i-joist can be drilled to a maximum depth of 60 percent of the depth of the wood. Notches can go to 40 percent deep.

Don't Use Metal Hangers

Extra pipe support may be required during PEX tubing installation. Provide this support with plastic hangers only. Metal hangers can damage the tube. Use the hangers that keep the pipe off the stud or joist to prevent water noise transfer

Using PEX tubing instead of traditional copper will save you time and headaches. Just remember these dos and don'ts!