PEX Tubing Issues

Betzon

I have a house that is 5 years old. Three years ago the PEX tubing going to my front outside water faucet split and burst. I was told it was from ice buildup, even though I know I made sure I turned off and drained the water prior to the winter. Since then, I've ensured I drained each year and used an insulated faucet cover during the winter months. I've had my basement done recently and during a check of the shut off values inside the house, I noticed both front and rear tubing has split. What am I doing wrong? The basement being insulated and the covers on the outside should alleviate ice buildup. Plus, the rear faucet was never turned on from last year. Why would it have split?

Daniel Holzman

I assume you shut the water off to the outside faucet using a valve located inside the house. All valves leak, some more than others, so simply shutting the valve off will not prevent water leaking past and filling up the tubing between the valve and the faucet. Assuming you left the faucet in the closed position, you could then get a pipe full of water that freezes solid and splits the PEX. The simple solution is to leave the faucet open in the winter, and shut the valve off inside the house. If you have a little downward pitch on the pipe leading to the outside faucet, water leaking past the inside valve should drain, avoiding freezing.

Alternatively, you can install a frost proof outside faucet. Even with them, you need to disconnect the hose to prevent freezing in the winter.

Mikelite80

Is the PEX outside? PEX isn't rated for UV exposure. I don't know all the details of using it outside but I remember reading it doesn't do well with UV. Might just need to replace with copper till inside.

Betzon

The tubing is inside.

plumber666

Not all valves leak, Daniel.

plumber666

Is the hose bibb pipe sloped so that when you shut off the valve and open the bibb, all the water drains out? Standing water in the pipe could've froze.

Alan

I was told (by a salesman or something like that) that pex was OK to freeze. It just expands, and then when it thaws back out, it goes back to it's original shape. How big of a split did it develop?

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Journeyman Plumber

Betzon

I make sure that I turn off the water from inside, then go outside and turn on the faucet ensuring all water is drained out. I disconnect all hoses and put a thermal cover over the faucet outside. It doesn't look like the shut off is lower than the faucet, they seem about parallel. Another neighbor told me it could be too small of a tube to handle the pressure from the garden hose?

Daniel Holzman

OK, let me try this again. You turn off the water from inside using a shutoff. Then you open the outside faucet to drain the water. Do you leave the outside faucet open all winter, or do you shut it for the winter? If you shut it, and the shutoff valve leaks even slightly (digression - in the industrial piping world, we always assume that valves will leak slightly eventually), you will eventually fill the pipe up with water between the shutoff and the faucet, and the water will freeze, cover or no cover, causing potential damage to the tubing.

PEX is pretty good at handling freezing, but it is NOT designed to be frozen, so if it somehow survives freezing, that is a bonus, not a design feature.

Betzon

I'm pretty sure I leave it open, but I can't recall now. I'll ensure I do that from now on. What about preasure, could that be a cause as well?

Daniel Holzman

PEX is typically rated for 100 psi cold, which is well above typical residential pressure. If you have more than 80 psi city pressure at the house, you should have a pressure reducing valve installed. Of course, if the PEX you have was damaged, left exposed to sunlight, or is substandard, it might not hold rated pressure.