The Pitfalls of PEX Plumbing


PEX plumbing became extremely popular for home renovations during the 80s and 90s. It was very popular in the US and many old houses are still using PEX plumbing. PEX was largely used as a substitute for tubing materials.

However, many disadvantages of PEX plumbing have come to light over the years. If you’re considering PEX plumbing for your remodel, you should go through the following details:

What Is PEX Plumbing?

Cross-linked polyethylene, commonly known as PEX is a plastic material used for plumbing systems that transport water. It was preferred due to its flexibility, ease of installation, higher resistance to heat and durability.

PEX was wildly popular in Europe since it was discovered by a German scientist. It reached the US in the 80s and was mainly used for floor heating systems. Nowadays, there are different types of PEX pipes available for different purposes.

Why Is PEX Plumbing Bad?

PEX plumbing might sound amazing but is notorious in the plumbing world for various reasons. While it is not illegal to use PEX plumbing, it certainly comes with a lot of pitfalls. Let’s dive deeper.


PEX is sensitive to UV rays emitted by the sun. PEX pipes can disintegrate over time if exposed to sunlight over a long period of time.

UV rays are emitted by the lights indoors too, so it is recommended to keep the area completely dark. While different manufacturers have different opinions on the amount of light or sunlight PEX plumbing can tolerate, most of them suggest insulated PEX for outdoor usage.


PEX pipes do not react well to chlorine, a chemical commonly found in water. Chlorine can erode the PEX material, causing leakages or even burst pipes.

There have been attempts to rectify this problem by adding antioxidants to the pipes, but they haven’t been very successful. Currently, PEX piping cannot withstand more than 4.3 ppm of chlorine in the water.


PEX pipes claim to last over 50 years. However, they need extremely favorable conditions for this to happen. They are susceptible to many environmental factors and may require constant maintenance.

PEX pipes are not recyclable, and cannot be used for other purposes later. Thus, sustainability is a major concern with PEX plumbing.

Water Quality

Wherever people use PEX plumbing in drinking water, there have been many complaints of bad taste and odor. The cause of this effect remains unknown, forcing people to change entire plumbing systems.


Zinc is used in all the fixtures used in pipe joints or connections. Water reacts with zinc and gets contaminated. The leaching of zinc weakens the joints too, eventually causing leaks.


PEX plumbing comes with a waterproof membrane, which is vulnerable to bacterial growth. Oxygen barriers are installed as a solution to this problem.

This can get expensive and a little complicated due to the flexibility of the PEX pipes. This is an unavoidable cost and needs to be budgeted when you estimate the cost of your renovations.

Fitting and Installation

You need PEX fitting tools for installation. You will need them for replacements and repairs, which might be needed multiple times over the years. You need to purchase these PEX tubing tools, which can be expensive.

All the connecting materials need to be thought over. Most of the connecting fixtures are made of brass or zinc, which are susceptible to corrosion. This reduces the quality of the heating systems.

The installation can get complicated due to the nature of the materials used. PEX pipes are not compatible with most plumbing materials and hence need constant checks before the installation is complete.


A lot of PEX users have reported that rodents damage their plumbing systems. Since PEX tubes are lighter and more flexible, pests like rats chew through the pipes. This leads to leakages and contamination of the water.

Water Vapor

PEX is generally recommended for indoor usage. This means that people use PEX pipes in kitchens and bathrooms. Proximity is unavoidable in these locations. Cold water pipes and hot water pipes always run together.

Even though the pipe won’t leak in this case, but condensation caused by water vapor rising from the pipes will produce water.


There are two chemicals left behind during the manufacturing of PEX, tert-butyl alcohol and methyl tertiary butyl ether. These chemicals can be hazardous to human health.

Manufacturers are required to test these chemicals before installing PEX pipes, otherwise, they leave you at risk for severe health complications. This particular effect came to light in the 2009 trial in California.


PEX plumbing is semi-permeable. This means that liquid can penetrate the pipe. When PEX pipes are installed deep underground, oxygen elements or petroleum can cause the pipes to disintegrate.

This leads to contamination of the water. There have even been cases where moisture-induced bacteria penetrated the pipes, contaminating the water flow.

What Is the Life Expectancy of PEX Plumbing?

Realistically, PEX plumbing can last from 25 to 40 years. It will need to be replaced after 40 years of usage.

However, over the years, PEX plumbing goes through a lot of wear and tear. Leaks or burst pipes are not very common, but as we’ve seen above, PEX plumbing is vulnerable to a lot of elements. Therefore, a fair amount of maintenance and upkeep is to be expected with PEX pipes.

In comparison, copper pipes can last anywhere between 50 to 70 years. Copper is also a lot more expensive than PEX, however, it is not vulnerable to sunlight or other elements. Copper pipes are affected by acidic water, so you will need to get your water supply tested.

Wrapping Up

As you’ve seen, there are many pitfalls to installing PEX plumbing. Medically, there hasn’t been any concrete proof of harmful effects, however, you still need to be mindful of the type of PEX you choose. Especially, if they have been tested for TBA or MTBE or not.

PEX pipes can be cumbersome to maintain, but they can certainly be easier to install, cost-effective and under the right conditions, long-lasting.

If you choose to avoid the complications of PEX plumbing choose a different material for your plumbing, there are many options to choose from.

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