Benefits and Disadvantages of PEX Plumbing. PEX vs Copper vs CPVC

Last updated: 1 May 2023

A PEX plumbing and why I’ve chosen this plumbing system for most of my builds. You know there are three main plumbing systems in American houses:

Copper

The gold standard has been around forever a lot of builders swear by it. If we have a zombie apocalypse you’re still going to be able to get copper fittings afterward impressive system a lot of builders won’t use anything but.

CPVC

A lot of production builders have moved to this. Much less cost initially than copper. Certainly less commodity base than copper. I used it for quite a few years actually when I build on the Northeast and had a success of it.

PEX

In the last 15 years, I’ve primarily used PEX for plumbing. PEX comes in three variations: PEX A, PEX B, and PEX C. This information is not sponsored, but rather intended to provide unbiased insight into the positives and negatives of these plumbing systems. PEX was first developed in Germany in the late 1960s and entered the European market in 1972.

Since then, it has been widely used in America. The primary reason for the shift from copper to PEX is cost. PEX piping is much less expensive than copper, and fittings and labor are also generally cheaper. Overall, using PEX can result in a more affordable build than copper. While there are some benefits to PEX, there are also a few downsides to consider.

Let’s run through all the benefits of PEX:

Really long runs. PEX pipe is flexible. We can home run things in all kinds of ways the snake through the house. Reduced fittings mean better reliability but it also means that we’re gonna have less pressure drop. Because we can bend pipe we’re not gonna have all the bends that we’re gonna have in a copper or CPVC system. And every time we get a bend we’ve got some potential for pressure drop and reduce flow.
Another big benefit of these flexible systems like PEX is you’re gonna have much less water hammer in your system. When your washing machine starts and stops filling when you turn off a faucet quickly that water hammer can translate in a pipe movement hitting the framing in your house and that’s called water hammer. You get much much less of that with a flexible pipe.
Next big benefit of PEX compared to copper, in particular, is that you’re not going to get calcium deposits sticking to your PEX where that can happen with copper you need to be cautious about those pipes squeezing down over time when you’ve got metal piping in your house.
And the last big benefit that I like about PEX compared to some other systems is the ability to withstand some freeze. You know this PEX piping because it’s got some amount of elasticity. We could have frozen water in this line the pipe could expand without bursting or without cracking whereas if you get a frozen pipe when it comes to seeing PVC or copper you’re gonna get a leak you’re gonna get a burst. So there are some definite benefits here. And as well because of that same flexibility we talked about if we were to get a kink we get too tight of a bend. We can get that kink out of your PVC by adding some heat.

Why is PEX plumbing bad?

If you read the Internet of course there are lots of horror stories about PEX. I don’t believe most of those but there is a certain amount of risk when you’re using a PEX system.
While using PEX fittings can result in cost savings, it’s worth noting that the manufacturing company could go out of business, making it harder to obtain fittings in the future. Additionally, there is some risk associated with using plastic fittings in your water supply system, particularly if your municipality uses high levels of chlorine in the water.

Chlorine has the potential to break down PEX over time. However, in my experience of using PEX for over 15 years and building several hundred houses annually, I’ve only encountered one fitting leak. Overall, I’ve found PEX to be a very reliable system with no issues with water taste or other common concerns. I’m a strong proponent of PEX and believe it’s a great choice for plumbing.

As we’re talking about this I want to point you to kind of the Godfather of hot water systems and distribution Gary Klein. He’s the guy that’s gonna help you do the architecture on your plumbing system. And in fact, he claims that you can get hot water almost anywhere in your house without wasting more than one or two cups of water down the drain before it gets hot. Very impressive guy. I like to follow his practices.