PEX plumbing is referred to cross-linked polyethylenes that are formed in the shape of a tube. As an alternative solution to copper pipes, this type of system has gained popularity over the years due to its flexibility and fit. It can be easily compared to copper or PVC. However, what is PEX plumbing, and is it bad for your home? research has shown that PEX is associated with a number of failures such as water leaks in hoses and fittings.

PEX fabrication types

The first and most common is the Engel process. This is an extrusion that is done with peroxide while the plastic is being molded based on pressure and temperature.

Silane method

Is made by the grafting of silane into a column of polyethylene and the use of a catalyst. The tubing is fed into an extruder and is in effect steam or hot water after extrusion.

The electron method

It starts with the extrusion of high-density polyethylene. After extrusion, small radiation injects into the extrusion, which causes the extrusion to initiate cross-linking.

With this tubing, nothing but benefits have been seen. Its flexibility, pressure capacity, resistance-free transportation, etc. Would make it a good choice for purchase as a construction material, but it has a number of flaws.

What’s wrong with PEX plumbing?

pex plumbing issues

There are a number of chemical interactions between the tubing and some chemical elements in the water. That cause leaks in both the fittings and the hose. Many fail when they come in contact with chlorine in the water, direct exposure to the sun, and the dezincification of their parts which results in corrosion.


Chlorine has a detrimental effect on the pipe. When it comes in contact with water, leading to failures that can cause leaks. To combat the effects of chlorine, manufacturers have added antioxidants. This action is not sufficient when the layer of antioxidants runs out, and the pipe becomes damaged.

Sunlight and UV rays

The PEX plumbing is vulnerable to sunlight and ultraviolet rays. This forces plumbers to locate pipes away from or hidden from sunlight and UV rays. Failures because of sunlight include loss of flexibility and elasticity. The solution to this failure is not to expose the pipe to the sun for 6 continuous months.


According to manufacturers, PEX pipes are permeable to certain products and oxygen. Although oxygen does not represent a problem. When they are closed networks, oxygen can cause oxidation or corrosion in the heating parts for example. When they locate underground, they can come into contact with other substances: such as oil residues and pesticides seep through this porosity and contaminate drinking water.


Failures in pipes due to pressure caused water leaks and led to the collapse of walls or floors, being highly costly to repair.


The pipe performs very well in warm temperatures but a freeze can cause the water and the pipe to freeze completely, causing the pipe to burst.

Chemical leaching

During the manufacturing process, chemical particles from the production process remain in the pipe, causing an increase in the concentration of chlorine. Another main reason for chemical leaching from PEX pipes is over-chlorination.


This process reacts to a portion of the pipe chemistry. It causes selective leaching of zinc from the brass alloy, resulting in the failure of fittings or weakening of the pipe causing leaks. The solution to this failure has been to change the brass parts, use polyester alloy fittings (which do not have a dezincification process) and are readily available and use the tubing between straight runs to avoid extra connections. The latter commonly use for momentary pipe repair.


pex plumbing fittings

Pipes are flexible for plumbing, but they require a few fittings that are so specific and of such special materials that can lead to higher costs in the end.


Just as PVC has special adhesives for insulating pipes, so does PEX. However, this limits and causes premature damage due to their detrimental effects. Therefore, a plumber should opt for other materials to insulate without side effects.

Is PEX plumbing good in any way?

It is not the first or the best option; due to its porosity, and it can contaminate the drinking water causing intestinal diseases. If they are to use them for the purpose of carrying potable water, the ideal is to install them in an isolated sleep with asphalt to avoid corrosion to the minimum and thus avoid water contamination.

With lining problems, you should ask about and test fittings such as clamps and use steel clamps on connections to avoid rapid rusting, remember to ask your supplier or contractor about this pipe and its frequent use in plumbing projects.

Not recommended as a first choice if you are building or renovating your home. Go for PVC pipe if you are looking to save money. Over the years it demonstrates that it is the best plastic pipe, economical, efficient, and durable.

Why is PEX plumbing bad? was last modified: December 16th, 2022 by Vanessa Gallanti
Your opinion matters, leave a comment
Inline Feedbacks
View all comments