What's The Big Deal With PEX Piping?

9 July 2015
 Categories: , Articles


When you think about plumbing, images of copper piping typically come to mind. Copper pipes have been the mainstay of residential plumbing thanks to their overall durability and other natural advantages. However, a growing number of contractors are installing PEX piping in place of traditional copper and PVC piping.

What is PEX?

"PEX" is shorthand for cross-linked polyethylene. Just as the name suggests, it's a unique type of polyethylene that features cross-linked bonds in its polymer structure. This beneficial change in the basic polymer structure helps improve its high-temperature properties, giving it significant strength while maintaining its overall flexibility.

PEX piping has gained popularity among plumbing contractors as an alternative to traditional copper piping. According to Jay Romano of the New York Times, the use of PEX piping for handling potable water increased by 40 percent for the past few years.

Advantages of PEX

There are several advantages to PEX piping that makes it attractive for both contractors and homeowners:

  • Flexibility is a major advantage of PEX piping. Whereas copper pipe relies on rigid elbow joints that can be time-consuming to create and install, PEX pipe can easily bend far enough to accommodate short radius turns. However, PEX piping still needs an elbow joint to safely and reliably handle 90-degree turns.
  • Installation is another advantage that PEX piping has over copper. Copper piping can be exceptionally labor-intensive to install since it requires joining sections of pipe with the help of solder and a propane torch. In comparison, the installation process for PEX pipe only requires the use of a special crimping tool or an adjustable wrench. PEX's installation process also forgoes the potential fire risk that often accompanies the installation of copper piping.
  • Cost is yet another perk of choosing PEX over copper. Given the recent rise in metal prices and subsequent concerns over copper theft, the average cost of copper plumbing has risen dramatically to around $2.55 per foot, according to Purdue University. In comparison, PEX pipe costs around 43 cents per foot, making it the least expensive of plastic pipes.

PEX Caveats

In spite of the advantages that PEX piping offers, there are a few noticeable drawbacks. For instance, PEX pipe degrades rapidly under exposure to sunlight. This means that PEX piping is a no-go for any application where exposure to sunlight is a given, unless it is properly shielded. PEX is also fairly vulnerable to perforation by certain types of plant feeding insects, especially the Western conifer seed bug.

There's also an ongoing debate on how PEX pipe affects home water quality. Researchers found that the chemicals commonly used in PEX could be detrimental to overall water quality. In some cases, even the water's taste and smell was altered by these chemicals; although, the water itself remained safe enough to drink without any adverse effects.

Researchers also noted that certain types of ground contaminants, including pesticides and gasoline, were more likely to permeate through PEX piping than other types of pipe.

How It Fares Against Copper Piping

In a showdown between copper and PEX, the latter usually wins hands-down. Unlike copper, there's no risk of PEX pipe developing pinholes or cracks due to corrosion. PEX also fares better under winter conditions, especially at temperatures where copper pipes are likely to burst.

In spite of its flexibility, most PEX piping setups have fewer sharp turns than a typical copper line. The sharp elbow joints commonly seen with copper plumbing can easily reduce overall water pressure, resulting in weaker sink, shower and toilet flow. With PEX pipes, fixtures are able to receive greater water pressure thanks to the gentler turns.

Now you know the big deal with PEX piping, a plumbing alternative that's continuing to gain traction among contractors for both renovations and new home builds. Thanks to its low cost, excellent durability and ease of installation, it's expected to play a prominent role in home plumbing system design for the foreseeable future. Contact local plumbing contractors for more information.