As a part of a larger job, I have a plumber replacing water lines. He is going to use PEX. I read that sunlight exposure causes PEX to become brittle very quickly (on the order of a couple of weeks). Based on the I-know-it-all attitude that the plumber has showed on other parts of the project, I am worried that he might have stored the pipe improperly. Is there a way for me to check the state of the pipe before the walls are closed?
Plumbing – How to check PEX pipe for embrittlement
plumbing
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Use conduit hangers sized for the insulation, screwed to the wall. Insulate both the hot and cold or the cold will sweat on humid days.
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I couldn't find a picture with these installed like that; here's an example though.
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One thing I would suggest is that you install blocks of wood (pieces of 2x4) so that the units cannot squish the pipe. That might be overkill but I don't like the idea of exposed and unprotected plastic pipe. Even if it was copper I'd try to protect it somehow. The only thing I wouldn't be worried about protecting would be flexible metallic supply lines. You can get them in surprisingly long lengths, or use nipples to connect two or more of them.
But the PEX is already in, so screw it. You just need some more insulation (for the cold side) and some conduit hangers (probably 1-1/2" or 2"). And something to keep the units away from the pipes.
"Black polyethylene" seems to commonly refer to HDPE pipe, which is pretty comparable to PEX. "Just" PE pipe is cheaper and less durable than HDPE - I'd advise against that underground.
PEXa ("Uponor/Wirsbo", "ProPEX", "F1960") is the best option, especially underground and in places with a potential for freezing, since it simply expands and contracts instead of bursting and leaking. However, PEXa is a bit more expensive and requires "expansion" style fittings, which while they are most reliable and free-flowing of all PEX connections, typically require more expensive tools that may not be worth it for a one time job if you can't rent them.
PEXc is the more common and typically cheapest form; connections are commonly "crimp" or "clamp" style which are more restrictive than expansion style, but the tool tends to be cheaper. PEXc will also expand and contract, but to a far lesser degree before risk of splitting.
Ultimately, PEX is the best option these days, but the type of PEX is more dependent on your situation.
- If you plan to do more plumbing in the future and/or the pipe could be subject to freezing, PEXa along with Milwaukee's expansion tool (Milwaukee #2432) is the way to go for worry-free connections. There are also hand tools available for about half the price of a used Milwaukee kit ($160-200 on eBay at the time of writing).
- If you can't rent or find the expansion tool for a reasonable price, or are simply more budget minded, PEXc using crimp or clamp style connections is likely the best path. Home Depot near me rents the tool for $16/day.
Best Answer
Most water PEX pipe has a UV stable outer coating.
Check the brand and spec sheets. If it is UV stable, its fine unless the sheath is cut or damaged.
NOTE: gas PEX does not have this coating.