Is PEX Waterline Always Okay, No It’s Not

PEX is a medium or high-density cross-linked polyethylene tubing used extensively to distribute water through homes.

Up to the 1960’s galvanized piping was used in homes and is very common to find yet today. Galvanized lines replaced lead water lines. After decades of exposure to water have caused galvanized pipes to corrode and rust on the inside. Many of these systems are outdated and in need or replacement.

From the 1960’ though 1980’s, copper tubing was the primary material for piping, but was a 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, builders had a troubled relationship with polybutylene and CPVC water lines before switching in earnest to PEX.  PEX 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.


F the most part PEX tubing is 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 brass, which is 35% zinc
  • Red brass, which has less than 15%.

Yellow brass is more prone to failure due to dezincification and three manufacturers 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.
  • NIBCO also experienced problems with its yellow brass fittings. The October 2018 settlement referenced below also covers failures of their fittings manufactured until 2012.


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.


To avoid the problem of dezincification, most PEX companies today use a resistant brass or PPSU (plastic) fitting.  NIBCO has not manufactured the 1006 type tubing since 2012 and I’m not aware of issues with other PEX tubing manufacturers.


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, 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.

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.