Cross Linked Polyethylene water tubing, or PEX, is a relatively new product which was first introduced in North America in 1984. PEX has been primarily used for radiant floor heating, and more recently water distribution systems. I love this stuff, and if you have any plumbing projects coming up, I recommend using PEX instead of copper. Here's why:
Ease of installation My favorite feature of PEX tubing is it's ease of installation. I've soldered plenty of copper tubing, and it's a time-consuming, pain-in-the-butt process. Every length of tubing and every fitting needs to be perfectly measured, cut, reamed, fluxed, and soldered. I get flux all over myself, I usually end of burning myself on a piece of copper that I forgot was hot, and much care needs to be taken to make sure the torch doesn't burn other materials in the home. With PEX, all of this hassle is completely eliminated. Because PEX is so flexible, you typically only need to eyeball the length of the tubing before cutting it, and the fittings are quite easy to join together – much easier than soldering! The first time I installed PEX tubing it was so easy and so fast that it felt like I was cheating. Plumbing isn't supposed to be this easy!
Better water flow Instead of running large branch lines through the house and tapping off the branch lines with smaller lines to feed bathrooms, kitchens, and other rooms, PEX can be configured in what's referred to as a 'Home Run'. This is done by installing a large manifold in the basement near where the water comes in to the house, and then running a separate water supply tube to every single plumbing fixture. You can then install shutoff valves for every single tube. This means that you'll have much less of a pressure drop when you're running more than one fixture at the same time. You can also install shutoff valves for every single line, so isolating a fixture can be done with ease.
Less prone to failure Most failures with water supply pipes happens at the fittings, not in the piping itself. With PEX, there are far fewer fittings needed because the material is so flexible. Because PEX is so flexible, it is also freeze-break resistant. In the last two years I've seen TONS of burst copper tubing from freeze damage, but I've never seen freeze damaged PEX tubing. PEX is also highly resistant to chemical damage.
With all the benefits that PEX offers, why are people still using copper? I don't claim to have an answer. Oh, and as for the title of this blog – what makes sliced bread so great? Don't get me wrong, I like sandwiches even more than the next person, but it wouldn't be fair to say that PEX is the 'greatest thing since sliced bread.' It's better.
Reuben Saltzman, Structure Tech Home Inspections – Email – Minnesota Home Inspector
