Using a small piece of PEX for a repair?

[toller]

I have never used PEX, but I understand it will survive freezing water. Is that correct?

I had a 3/8" soft copper pipe freeze and burst. A plumber put it in a couple years ago when he installed a dishwasher. There is a dip in it where it goes under a joist, so when drained my pipes last fall water pooled in it and froze. There is no particular reason it shouldn't happen again; I am surprised it didn't happen the previous two years. However getting to it to work a drain pipe would be a real pain. I could blow it out with compressed air, but that wouldn't be so easy either. Is it reasonable to replace it with PEX; without spending serious money on tools. I only want one 3' piece. How would I attach it to the 3/8 copper?

Thanks.

[Edwin Pawlowski]

PEX is better than copper but can still freeze and split. Look here

It can be attached with couplings to the copper. Most plumbing supply stores carry PEX in 250' rolls but a local hardware store has it in 25' coils. They also have the fittings. I used it for the first time a couple of weeks ago and it save me a lot of aggravation compared to replacing the copper that leaked.

[toller]

I see that Qest compression fittings can be used on either PEX or copper. Can all compression fitting work on PEX?

[stretch]

Use the Qest on poly & PEX. Regular compression fittings will cut into the plastic tubing enough to weaked it. Or you can use regular compression fittings with plastic ferrules. Don't use brass compression rings on plastic tubing.

Stretch

[Edwin Pawlowski]

No, some are made specifically for pex to pex and pex to copper or other materials.

[Chip C]

pooled in it

surprised it

The advantage to Pex is that it's flexible enough that you may be able to drill through the joist and fit the pex through the hole so there's no low spot. Whatever you do, you should try to avoid a low spot like that.

Around here some of the bigboxes carry something called "ipex aqua". It's a sandwich of pex on thin aluminum; its chief advantage seems to be that the fittings are tightened with wrenches, no special crimp tool needed. The only special tools that are "mandatory" are a pipe cutter and a reamer, each about $10. It has combination fittings for other materials, including both sweat and compression ones for copper. I bought a length of it for a small job like yours but haven't used it yet.

Like regular pex, the literature suggests it may be slightly more tolerant of freezing than copper but still cautions strongly against letting it freeze.

Chip C Toronto

[toller]

Thats a good idea. If I run it though a joist I can get it to slope. thanks

[Doug Miller]

Of course, you can do exactly the same thing with soft copper, too. It's a little trickier, but certainly doable.

-- Regards, Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?