PEX piping outdoors? (freezing)

[Number21]

I recently moved into a new shop, across from my old one, which is a small industrial building that I lease. Problem is my shop is a LONG way from the water meter, and, whoever plumbed the place was an idiot. The water flow out of my hose at the new place is less than 200GPH max. The water flow is so low that if I open more than one hose bib water will only come out of one of them. The other ***** air.

Anyway, I was thinking about running a peice of 3/4" PEX tubing from the front of the main building, where the pressure and flow is good, to my building. It would be about 200' total, approximately 150' inside a warm attic space.

The problem is, to get to my building I would like to run it across the back of a 50' long cinderblock wall. It *USUALLY* doesn't freeze much around here, but it certainly will a few times a year. I could insulate it, I could heat it, etc, but I don't want to. If it freezes shut every now and then I'm fine with that.

The question is can PEX tubing withstand freezing and thawing like this? I've heard that it can. The other problem is UV light. Is there such a thing as UV resistant PEX? Or maybe I could run it inside of a 1" grey PVC electrical conduit...

 

[cncjerry]

Well I don't know what type of code violation if any you will get into but I have seen PEX freeze solid and expand then thaw and be fine I only saw it once and fixed the issue, I don't know if it can handle repeated freeze and thaw.

 

[ixlr8]

Most PEX can stand limited freezing/thawing, but the fittings can't. Most PEX can't tolerate UV, it breaks down the bonds. From the training session I went to at Wirsbo/Uponor, they recommend no more than 30 days direct exposure to the sun before they will no longer warrenty it. I would run it inside a conduit of some sort.

 

[Number21]

I have seen PEX freeze solid and expand then thaw and be fine I only saw it once and fixed the issue, I don't know if it can handle repeated freeze and thaw.

Yeah, that's mostly what I'm wondering about. I imagine if I ran it inside a conduit that would give it *some* insulation and I could always leave a tap cracked open to keep it from freezing, however I do want it to be "idiot proof", meaning I can just let it freeze if I don't get around to doing anything about it...

As far as code issues, nothing else in the building is up to code, I don't see any reason to start now. And the landlord agrees.