Disadvantages Of PEX: Why Is It Not A Good Alternative!

While PEX has several advantages, it has some disadvantages as well. PEX is very sensitive to UV rays, hence intended only for indoor use. Besides that, PEX cannot be connected in high heat areas. Also, PEX can’t be reused and is highly susceptible to moisture and bacteria. Furthermore, it can be easily impaired by rats and solvents. 

Before discussing in detail further its drawback, let’s see the actual meaning of PEX first. PEX is a short form for “cross-linked polyethylene.” It is new in plumbing (approximately 20 years since its inception in the United States). The most special feature of this material is its flexibility. With its flexibility, plumbers can do an installation without obstacles while using fewer fittings. Also, with its flexibility, the installation speed increases and is excellent when it comes to resisting the effects of thawing and freezing. Isn’t that amazing? 

Disadvantages Of PEX

Disadvantages Of PEX 

PEX Can Filter BPA And Other Poisonous Chemicals 

Health concerns are significant. That is why it’s good to have informed decisions on this issue of PEX leaching toxic chemicals. With its three types (A, B, and C), type B is the only one that doesn’t seem to have a leaching problem. Suppose you want to use PEX, select type B. However, the research is still partial on this matter. 

PEX Is Very Sensitive To UV Rays

Most manufacturers suggest a limited amount of light exposure to PEX piping. Prolonged exposure can cause a lot of damages to this type of plastic water line.  Sunlight isn’t the only UV light, but also bulbs in your place are UV light. So, you should not install PEX near bulbs in your house but instead install them in total darkness. 

PEX Cannot Be Connected In High Heat Areas 

It is not recommendable to install PEX in high heat areas like near sunken lighting. This indicates that you cannot connect PEX directly to hot water as well. Instead, you can use a connecting material to do so. 

PEX Can Be Impaired By Chemicals And Pests 

According to pest control companies, pests such as mice and rats can access the external of your PEX plastic piping by masticating on the plastic. Other types of piping material, such as metal and copper, are designed to withstand pests. If you come across mice in your house, it is crucial to contact an exterminator to prevent damage to your furniture, drywall, and pipes. 

PEX Is Semi-Permeable

This means liquid can pass into the pipe. So, when it comes to safety, PEX is not uncontaminated. That’s the key reason people don’t select PEX when it comes to PEX vs. copper decision. The plastic material also permits water to pass into the tube, which might cause contamination. 

It’s for these reasons; there are in-depth discussions of a PEX pipe recall going on. But the final decision has not been made yet. 

PEX Can Not Be Recycled 

PEX has a shorter lifespan, and due to that, it cannot be recycled. On the other hand, copper and metals can be reused. 

Other Drawbacks 

1. PEX installation requires a lot of support when compared to other piping materials. If it does not work correctly, the pipe may move inside the partition through the opening and closing water. 

2. It might be damaged if left outside for a prolonged time

3. Susceptible to bacterial 

4. PEX can only be used on smaller size branch piping. Its size goes up 1”, so if you require a bit larger size, you to change to copper. 

5. Labour is less skilled in some instances. The tradesman who brought up the installation of copper is likely to be skillful to the PEX system.

6. PEX has fewer fittings. Even though inconvenience is eliminated because of the piping flexibility, but still, someone can run into situations where they will regret not choosing copper fittings. 

7. Disordered installment. It looks sloppy and not pretty to look at, but it works. 

Why Is PEX Banned In California?

There was a concern that PEX can leach some dangerous chemicals into the water. That’s the critical reason California’s Building standards Commission banned it. They believed that PEX might cause exposure to dangerous chemicals, which may lead to adverse effects. 

Should I Use PEX A Or PEX B?

Staying in a cold surrounding indicates your plumbing system faces the risk of freezing in extreme temperatures. And as you know, when pipes freeze, they may burst. PEX A and PEX B have different ways of responding to such a risk.  PEX A is more resilient to burst pressure compared to PEX B.


Let’s see PEX A vs. PEX B in detail to have a more informed decision. 


Even though the materials, sleeves, and fittings for PEX A and PEX B are prone to fluctuation, PEX B is the overall low-priced material.


Material: $0.21/foot 

Sleeves: $0.20/each 

90 degrees Fittings: $1.44/each 


Material: $0.35/FOOT

Sleeves: $1.00/ each 

90 degrees fittings: $0.15/ each 



PEX A is very flexible, which lets you create closer radial bends than PEX B. Also, if PEX A pipe bends, you can patch-up using a heat gun.  The heat will make the material expand back to its original shape. 


PEX B flexibility is limited given that it’s not made from the same expansive materials as PEX A. So, if the pipe bends, it hard to repair. The only option is to censor it out and start over.

Joining Method 

By observing these pipes sides by side, you will notice that they are almost the same size. However, the difference results from flow restriction. 


PEX A adopts the use of expansion style fitting.  These fittings are wide in diameter than the PEX B fittings and need n expansion tool. Using the expansion instrument, you widen the pipe and leave to enable slide in the fittings. Since PEX is expandible, the material memorial will make sure it shrinks back to its original size, narrowing around the fitting.  

Pros: The PEX A joining method gets rid of flow restriction given that its fitting has the same diameter as the pipe. Plus, the expansion fitting is perfect for tight spaces.

Con: if you stay in cold environments, it can take a long time for expansion-style fittings to shrink back to their standard size. But the great this is that there is a solution. Take a heat gun, and heat the fitting to fasten the process. 


PEX B uses a different fitting from PEX A. It uses an insert-style fitting. In this fitting, once you insert the fitting into the pipe, you affix it in place with a copper sleeve with the crimp instrument.

Pros: Its joining method is faster and more straightforward than that of PEX A because it doesn’t need an expansion tool. Both in the cold and hot weather, the joining method workflow doesn’t change. 

Cons: its joining method cut back the diameter of the pipe at the joint given that its fittings are smaller in diameter. Due to that, you will experience more significant resistance to flow and a reduced capacity of water in your household. Plus, its joining method is less ergonomic compared to PEX A.

Sizing The System 

A wrongly sized system is a significant problem service techs experience in the field. This problem is frequently linked to PEX B plumbing systems. As mentioned earlier, PEX B’s insert-style fitting may cause holdup in your plumbing system. So, if you intend to install PEX B, ensure you upsize your system to minimize flow restriction. 

As for PEX A, there is no need to worry because it uses an expansion-style fitting. 

Burst Pressure 

Staying in cold surroundings means your plumbing system faces the risk of freezing in extreme temperatures.  And once the pipe freeze, it may burst.  Both PEX A and PEX B respond to risk differently.  For instance. PEX A is more resistant to burst pressure compared to PEX B. 

PEX A’s expansive material is deemed to handle up to 500 PSI, making it steadfast in a freezing temperature. PEX B is a bit rigid; hence it will not hold up to that extend. 


PEX A is much better than PEX B in terms of various things. From warranty, cost-savings, better systems, among others. So, we consider PEX A the winner.

Should You Insulate The PEX Pipe?

Pipe insulation is a wise thing to do. Insulation promotes energy efficiency and minimizes possible glitches linked to condensation and moisture.  

Before taking the step of insulating your pipes, you must consider what kind of pipe you are dealing with and its cost. Since we are dealing with PEX, here are few tips for its insulation:

1. Choose the correct insulation material 

2. Before you insulate, take a few minutes to clean the surface of the PEX piping

3. Seal it entirely within the insulation 

Final Word

There isn’t an ideal material for water pipes. Every material for water pipes has its pros and cons. So, it’s upon you to choose which one is the best for your home. As for PEX, it is not ideal for areas that experience high heat and cannot be connected directly to hot water. Besides, it is not recyclable and can expose you to harmful BPA chemicals, which is why it is banned in California. 

Leave a Comment