Why is PEX Plumbing Bad? The Truth Explained!

PEX pipes rose to prominence in Europe and then in the United States. In the US, it took the industry by storm.

However, have you ever wondered why is it that people are still unsure regarding the utilization of PEX plumbing in their houses? The article explains the facts that show the downfall of PEX as a substitute for other tubing material.

PEX has been in the industry for a while now. Although most of the concerns are well-mitigated now, it is still worth knowing why PEX plumbing is considered bad.

Why PEX Plumbing is Considered Bad?

PEX plumbing has got a really bad name in the industry, but we need to dig a bit deeper to know the exact reasons why PEX pipe is considered bad.

Before we dive deep into these, remember that it’s quite safe to use PEX in a plumbing system now when you act according to the local law.

The Impact of the Sun

Sun rays are harmful to PEX plumbing. PEX cannot withstand the ultraviolet rays, nor is it a good way to go where direct sunlight is available throughout the day. Insulated PEX is recommended if you want to use PEX for outdoor use.

Bacterial Growth

Bacteria can grow in PEX plumbing because of the waterproof membrane. Bacterial growth is avoided by the installation of oxygen barriers. It is a compulsory item for the PEX plumbing and is costly. 

Although the installation is easier, the bending curve is longer, which can lead to a wrong installation. 

Critics also claim that PEX plumbing material does not correspond to sustainable practices, due to the shortness of the lifespan, and the incapacity of the product to be recycled for other purposes.

why is pex plumbing bad or good

The Impact of Chlorine

Chlorine directly affects the reliability and lifespan of PEX pipes as it erodes the surface and causes leakages. Leakage can cause loss of water pressure as well as contamination of the water sources.

Although PEX can withstand chlorine up to 4.3 ppm in water, still there is a risk of degradation.

Impact of Zinc

Zinc is present in the brass tools that are used in the joints or other places of connection. The zinc reacts with the water and causes contamination. 

This zinc leaching causes the brass connectors to get weak and thus results in the joint’s weakening. Eventually, water gets leaked, and external elements pollute the water. 


PEX is permeable to oxygen elements and petroleum. If the plumbing is near or inside an acidic soil that contains the permeable elements, the piping gets cracked or corroded faster than expected. Expectedly, crack or corrosion will result in contamination of the water.


A PEX pipe lasts approximately 50 years, but only in favorable situations. And it is quite obvious that a whopping 50 years long journey won’t be a smooth one. As a result, PEX doesn’t last that long. The pipe will need cold water to run through it for stability.

It should not be placed even near the hot water line so that the water vapors never condense, and it should also be reinforced if it is a hot water line.

The Fitting Tools

PEX tubing tools come at a high price, which is generally essential whenever PEX plumbing pipes need to be replaced or repaired. Mainly because those replacements can be often critical, you must purchase the tools. No matter you are using PEX for gas line or for hot water.

Brass fittings are used to connect PEX pipes. Such materials are susceptible to corrosion, so you need to pay close attention to the choice of materials for the plaster. It is better not to use materials that cause corrosion of the fixture; otherwise, the heating system’s quality will noticeably decrease. 


One of the main problems for a PEX plumbing pipe is condensation from the water vapors. Many people use PEX indoors for the kitchen or bathroom. In such cases, it is unavoidable that the cold-water line remains close to the hot water line.

Due to this fact, the water will surely leak to the floor not from a PEX plumbing pipe but in the vapors that form between the two pipe joints.


The installation of PEX plumbing is technical and requires careful consideration. The plumbers are wary of the crimping, clamping, and other tools that are associated with the plumbing. PEX requires a lot of tools, connectors, and special joints. The joints are always checked before the installation.

Slight error or mistake in the installation can result in devastation. As mentioned above, PEX has fewer allies and many enemies. Any crack, damaged part, loose connection, etc., have to be checked before finalization of the installation. 

The rodents or other underground animals can easily damage the piping because of the softness of the material. The cracks or breakage can lead to pollution of the water reserve and the household water.


In contrast to the cost of metal-plastic and ordinary polyethylene, the price of such pipes is quite high because of the tools that are used for establishing connections. You might want to consider buying an economical and reliable pipe than a costly and non-durable one.


Methyl Tertiary Butyl Ether and Tert-Butyl Alcohol are the residues left behind during the Engel process of manufacturing PEX. These two chemicals and the rest of the above drawbacks led to the famous California trial of July 2009. The two chemicals are a source of contamination with severe adverse effects on human health.

The two chemicals must be tested before installing the pipes; otherwise, the chemicals can damage your health and cause health complications.


PEX cannot be recycled. It is entirely replaced after its lifespan ends. The polymer has no further use and is discarded. So, many people think PEX pipes are a type of pollution as we cannot recycle them.

Read: PEX Crimp vs Clamp Comparison


The drawbacks mentioned above are based on scientific and historical facts concerning the PEX plumbing system. The water flowing inside the PEX can be contaminated for multiple reasons and might contain toxic chemicals.

These disadvantages inform us that PEX is not a reliable source for plumbing unless you are making the atmosphere favorable for the PEX.

Not to worry! PEX is allowed to use in residential areas, as residential setups are not susceptible to extreme temperature changes. To know more about this, read our guide on Where is PEX not Allowed or Banned.

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