PEX Plumbing for the DIY’er

By Matt Weber, Photos By Hal Jones

Faster, Easier and Less Expensive than Old-fashioned Plumbing Methods.

The evolution of plumbing has given rise to PEX as a new standard in construction. Whereas traditional copper supply lines still provide a very strong, reliable connection for water lines, the metal is much more expensive to purchase and more time-consuming to install. PEX supply lines offer a comparatively easy-to-install solution, and the material cost is much less. For these reasons, professional contractors are using PEX more and more, and do-it-yourselfers can take a cue from the pros.

Why PEX?

“Builders around here have pretty much moved exclusively to PEX for new construction,” says Richie Hamilton, professional builder/remodeler in Birmingham, Alabama. “Since copper is so expensive, a lot of contractors have problems with thieves breaking into homes under construction and tearing the copper right out of the walls to get the salvage cost.” This means not only are those contractors forced to replace the high cost of copper, but also forced to spend time, money and labor on reinstallation—not a good prospect for a builder’s bottom line.

PEX is cross-linked polyethylene pipe. It was developed in the 1960s and introduced to the United States in the ‘80s. After under-going several manufacturing processes, the material becomes resistant to extreme temperatures (hot or cold). It also resists deformation from long-term exposure to stress, as well as chemical attack from acids and alkalis. PEX is flexible and suitable for use in temperatures below freezing and up to 200 degrees Fahrenheit. This makes PEX an excellent piping material for hot and cold water potable water systems, as well as radiant heat flooring.

Its flexibility is one of the major advantages of PEX. When running supply lines through a stud wall, PEX is easy to thread through the stud holes without binding against the wood, as a rigid copper pipe can do. When a pipe reaches a corner, a copper pipe must be cut, then fitted with a 90-degree elbow, fluxed and soldered, and then joined to a second length of pipe using the same soldering process. With PEX supply line, simply bend the flexible pipe through the corner studs—no joint is necessary. Fewer joints save time, which can bring down costs for the contractor and the homeowner. Fewer joints also mean less chance of a leak. PEX is available in 1/4- through 1-inchsizes, and the material’s flexibility allows it to expand and contract to reduce the risk of a burst pipe. Furthermore, flexible systems are quieter than rigid piping.

On top of all this, a PEX system has a shutoff valve at each supply line. This makes it more convenient to cut off the water supply when making repairs or working on plumbing fixtures.

Note: PEX tubing is approved in all the current model-plumbing codes, but some jurisdictions may not have amended the code to include PEX tubing. Contact the local authority with jurisdiction over plumbing to verify the acceptance of PEX tubing for plumbing applications in your area.

Shown is a PEX manifold built by the EHT staff during a recent bathroom addition. The manifold allows different lines of the pipe to be shut-off for easy maintenance or repairs.