PEX is a medium or high-density cross-linked polyethylene tubing used extensively to distribute water through Triangle homes. Until the 80’s, copper tubing was the Triangle’s primary, but costly piping material. Copper is not only expensive but using a torch to solder every joint also makes it costly to install.

Why do we care?

Because it’s used extensively to distribute water through to Triangle homes.

Until the 80’s, copper tubing was the Triangle’s primary, but costly piping material. Copper is not only expensive, but using a torch to solder every joint also makes it costly to install.

Through the mid-90’s, our builders had a troubled relationship with polybutylene and then switched in earnest to PEX. It’s relatively easy to install and, for the most part, a robust material. Compared to copper, PEX

· resists scale build-up.

· is more resistant to freeze.

· does not pit or corrode when exposed to acidic water.

· does not as readily transfer heat.

· distributes water more quietly virtually eliminating “water hammer” noise.

PROBLEM WITH THE FITTINGS?

Yes, I did say “for the most part.” Through the early 2000’s, PEX tubing was often joined together with brass fittings, which can de-zincify. It is believed hard water (water having high levels of carbonates, oxygen, chlorine or fluorine) leaches zinc from the fitting, leaving it porous and prone to failure. The leached zinc oxide also builds up inside the fittings and tubing, causing clogs and reducing water pressure at the faucets.

There are two types of brass found in residential water fittings - yellow, which is 35% zinc and red, which has less than 15%. Yellow brass is more prone to failure due to dezincification and three manufacturers in particular have experienced problems.

Zurn Industries used yellow brass from 1996 until 2010 to manufacture their “QPex” brand fittings. A US class action lawsuit alleging excessive failure was brought against Zurn who settled without admitting there was a defect. Click here for more information regarding the Zurn lawsuit.

Kitec is another brand of plumbing system that was the subject of a class action suit in Nevada due to fitting failures. Manufactured by a Canadian corporation named IPEX, it sold in the United States until 2007. The Kitec system usually is made up of blue and orange tubing.

As with ZURN and Kitec, NIBCO also experienced problems with its yellow brass fittings. The October, 2018 settlement referenced below also covers failures of their fittings manufactured until 2012.

NOW THE TUBING TOO?

At the end of October, 2018, NIBCO INC reached a settlement to resolve issues related to its NEXT-Pure and DURA-PEX brand tubing that was manufactured until 2012. The NIBCO tubing can sometimes split and leak into wall cavities causing damage that is not visible until it has soaked through drywall or other building materials. The Settlement Class includes all persons that own or have owned a home that contains or contained NIBCO’s Tubing since January 1, 2005. The compensation is limited to those who have paid to repair “qualifying” leaks and covers only a portion of the cost to completely re-plumb a home that has experienced three or more separate “qualifying” leaks. Click here for more information regarding the NIBCO lawsuit.

WHAT ABOUT TODAY?

To avoid the problem of dezincification, most PEX companies today use a resistant brass or PPSU (plastic) fitting. In the triangle, it seems builders and plumbers have used plastic fittings almost exclusively since ~2010. NIBCO has not manufactured the 1006 type tubing since 2012 and I’m not aware of issues with other PEX tubing manufacturers.

SO, WHAT’S THE BOTTOM LINE?

No, PEX is not a cause for widespread panic - it requires routine inspection for signs of potential failure. Things to lookout for are corrosion and leaking (duh), especially if the fittings are brass and have the QPEX or NIBCO brand. Refer your concerns to a licensed plumbing contractor. It can be difficult to identify, but installations of tubing labeled DURA-PEX, NEXT-Pure or CPI should be noted.

Other problems related to installation (versus material) can also cause a PEX system to leak, but that’s a topic for another day...

The information provided here is based on extensive research, but I am an inspector - not a licensed plumber. Always consult a licensed plumber regarding a particular installation.