Where is PEX Not Allowed or Banned? Why is That?

Have you ever wondered whether PEX is allowed in your region or not? If you do, then we are here to solve this puzzle for you.

PEX has been a go to material for plumbing system, especially in North America for its availability, flexibility, and better value for money than most other plumbing solutions.

However, there are some places where PEX is not allowed to use. You may be wondering why! That’s what we are going to unfold in this article. So, keep reading!

Where is PEX Not Allowed?

We can’t deny that PEX is a preferable choice to use in different places as it is made of cross-linked, high-density polyethene. It is used in water pipe and cooling systems. Despite having so many benefits, there are some places where PEX is not allowed. That Includes:

  • Commercial Areas
  • Industrial Buildings
  • Residential Areas
  • California
  • Some Local codes

Why Is PEX Not Allowed In California?

PEX installation was not allowed in California until 2010. California’s standard commission banned it as there was few findings that showed some chemicals are draining away from PEX pipe into the water. Also, PEX is not antibacterial that lead to contamination.

Ultimately, California’s authorities didn’t allow the use of PEX as it may cause extreme manifestation to chemicals that later have terrible effects on people’s health. To know more about this, we have a dedicated article on PEX ban in California. It’s worth a read.

In Local Codes

Some local codes still do not permit the use of PEX because the plastic pipe and fitting association (PPFA) is contemplating particular cases about the safety of PEX. So, before you use PEX, make sure to check your local law if they permit using this.

In Commercial And Industrial Buildings

The common reason for not using PEX in commercial and industrial areas is its codes and buildings’ architectural and fire restrictions. PEX pipes have a combustible factor as their flame spread rating (FSR) is equal to 25, and the SDC is less than 50.

According to research, any pipe with FSR equal to or more than 25 should not be permitted in any commercial areas. Also, you can’t install PEX pipe with a high SDC factor in tall commercial and industrial buildings or neighbourhoods.

Furthermore, there is also a concern that a particular type of PEX contains BPA, and it’s common knowledge that PEX is high-density polyethene. So, if the material comes in contact with the fire by any chance, then it can cause a hazardous effect on health.

where pex not allowed

In Residential Areas

In residential areas, PEX plumbing is mostly legal but DIY installation is not preferable as some people make the mistake of fitting the PEX pipe directly to the heater. However, you should not install PEX in a high heat area. So, when the hot water comes out, it can cause PEX to stay permanently heated because of its contact with the heater.

Moreover, if the heater is at or above 180 degrees, then it will be too hot for PEX to handle. No matter if the temperature drops later, you can’t redeem its effects on the pipe.

If PEX is not connected to the heater and it is installed without adequate support, you may see it moving due to the expansion and contraction of the pipe. This happens due to the heating and cooling of the pipe.

Furthermore, its soft material can tempt the rodents of your home to chew on it. Although the pipe is thick enough to be protected against rodents, if rodents keep attacking the same place of the pipe, it may eventually leak and the system may get contaminated. These issues are prominent causes behind non preference, and sometimes banning of the use of the PEX in residential areas.

However, new technologies are evolving with the time, and today, PEX is a lot safer than before. Modern PEX pipes can withstand a massive amount of heat and cold, while preventing rodents from biting the pipe.

Read Our Guide on PEX Cinch Tools


Lastly, there could be many other reasons for not allowing the PEX installation in industrial, commercial and residential areas. It’s essential to keep in mind all the factors when you are up to some home remodeling or preparing a commercial space.

Despite its ease of installation or great affordability, we can’t deny that it can harm people’s health in many scenarios. After all, safety comes first. Furthermore, when the water remains in the PEX pipes for a long time, it changes its taste and odour.

I hope this article provided you with the information to solve all your queries about why some areas are still don’t allow using PEX!

Read: PEX vs Copper Differences

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