Now that the plumber is doing some rough-in work, I’m able to see what materials they are using and get a feel for what runs where, etc…  You might be asking yourself, why would I have not known what materials they are using for the plumbing?  The honest answer is, I don’t know enough about plumbing to ask.  In fact, I had never heard about or seen Pex tubing until it was installed this week!

Like I’ve said in the past, I like to learn about what’s going into the house , so I decided I had better understand what the funky red and blue tubing was!  In all of our previous homes, everything but gas and waste was copper, but we always bought homes built before 1960.  Seeing the tubing running around truthfully made me a little nervous.

What is Pex?

After a bunch of reading, I was able to conclude that PEX stands for:

P – Poly
E – Ethylene
X – Cross linked

In other words, Pex is cross-linked polyethylene where one or more processes is used to create links between polyethylene molecules, creating strong bridges (thus cross-linked).  Developed in the 1960s, it has been used in Europe for many plumbing and radiant heating applications since.  It only made it’s way to the US in the 1980s.  So, the technology isn’t new, which eases my worries a bit.

Pros of Pex

- It is far more flexible and stronger than copper at a wider temperature range (below freezing to 200 degrees Fahrenheit)
- It’s flexible so less elbows are needed
- It uses fewer fittings, which means less leaking potential
- It’s more burst resistant due to it’s ability to flex
- There’s a shutoff valve at each supply line, making it easier when repairs are done
- Personal Opinion:  the colors make it easy to tell which is hot and which is cold :)
- With the current price of copper, it’s no longer the expensive option
- Less theft risk because less copper is used

Cons of Pex

- It cannot be used outside because of it’s need to avoid UV light in high amounts
- Not 100% bacteria resistant like copper (more on this below)

Legionella and Plastic Pipes

As I mentioned above, there are rumors around online that plastic pipes can lead to the build up of biofilm on the inside under certain, rare circumstances like having pipes sit for a very long time with stagnant water in a home with a well, or with untreated water.  Biofilm can lead to Legionella growing.

I couldn’t find a single resource online that without a doubt said this was the case, only that it could happen.  This article and study:


says that copper has the same risks.  Other articles I’ve read say that if the municipal water supply is treated (as most is), the risk is pretty non-existent.  I feel that there is just as much of a risk with drinking public water that has contaminants as there is in having issues with PEX.

Working with PEX

My research was very conclusive that plumbers like working with PEX and that once the tools are purchased, it is much easier to work with and faster to install.  I found a good video from a Pex supplier that shows how the connections are made and the different options:

Cold Climate Advantages

Living in an area that has very cold winters, freezing pipes are pretty common.  We obviously hope that with new construction and a full basement, that won’t be an issue for us.  If, by chance we are away for an extended period of time in the winter, and the electric goes out, there is obviously a chance that the pipes could freeze.

The nice thing about the PEX tubing is that it expands and us much less likely to burst.