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!
PEX Tubing Installation FAQ
What is the best way to install PEX tubing?
PEX tubing, or PEX piping, is never glued or soldered as metal pipes are. Fittings are used with cinch clamps to bring pieces of pipe together can create elbows and bends in the pipe.
Because PEX comes in long rolls, you won't need to use a lot of fittings to install PEX. However, it does need to be supported every 32 inches when running horizontally and every four to six feet when vertically installed.
PEX must have these supports because PEX cannot be pulled tight.
Should I bend PEX or use an elbow?
Rather than elbows, use PEX bend supports for PEX piping. While they do not create sharp turns, they are perfectly functional.
Which is better plastic or metal PEX fittings?
Though brass is often used with PEX, plastic fittings work as well and tend to be more affordable at some stores.
Do mice eat PEX pipe?
Rodents are chewers by nature and they will chew on anything, even PEX pipes and even plastic PEX piping.
What is the life expectancy of PEX tubing?
On average, barring any unforeseen damage, PEX can last about 50 years with normal wear and tear before it will need to be replaced.
