How long can PEX be exposed to sunlight through a window?
derekr
| Posted in General Questions on
I had my plumbing done almost a year ago now but during Covid I had to wait 7 months for my windows
my plumbing was done before my windows so the plumbing hasn’t been covered by drywall or anything for 8 months now
with that said none of the plumbing has really been touched by any sunlight, except for 1 spot where the sun comes through my side door for about 2-3 hrs per day, this is the case for some romex wiring in that 1 spot as well but that wiring has only been there for 2 or 3 months
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So just to clarify, when you say "through a window", you mean a window opening with no glass? But also, the sunlight is not hitting the PEX directly? And the spot that gets hits directly is through a door...is that an open doorway, or glazed door?
Ballpark numbers, PEX should be ok for 30, maybe 60 days in the sun (depending where you read). Now I'm assuming that means completely exposed, no shade. 2-3 hours for a day might equate to about 1/4 to 1/6 of a day of full exposure. That would raise your time limit from 30-60 days to more like 120-360 days, which is a pretty wide range, and one end of the extreme would be ok, the other not ok. How risky it is also depends on your lattitude, as the rating they put on it would have to account for the lowest lattitude in their market region. How difficult would it be to replace that section, and how catastrophic would it be if it burst? Can you monitor it over time?
I wouldn't be overly concerned about sections in full shade.
It’s a door with a full glass window, sun comes directly through it at the end of the day as the sun is setting, it hits approx 6-8 feet worth of PEX going up a stud. It probably didn’t do this in the summer time, just fall and winter
I figure I have another 3 months or so before drywall
Wish I knew about this before I would have put up a sheet of osb in front of it or something
UV is what breaks down PEX, and most of that gets blocked by window glass. UVB for sure. I've seen some claims that UVA comes through, but the same sources claim you can get a suntan indoors. I've never seen or heard of that actually happening. I have a spot in my utility room where a couple of sections of uncovered PEX face an east, fully glazed door. Been like that for 5 years, I see no signs of deterioration.
Ok maybe I’m ok then, I guess the romex would find too
This house has been a long project since I started during Covidp
The Romex isn't pressurized, so once it's covered it's hard to imagine anything causing it to physically fail, not to mention there's another layer of insulation before you get to the conductors.
Well the PEX is no longer pressurized either because it was done 8 months ago, it was at 100 psi for probably 2 months then has slowly been going down ever since and now it’s at 10 psi
Oh nm you meant when the water is in it permanently
I have to get the plumber to come out and repressure it before Inspection
If the PEX has a UV stabilizer in it (check the product docs), it will hold up a lot better. The window glass will block much of the UV as has been mentioned, and the Low-E coatings block the far infrared which is what tends to heat things up and cause damage that way.
My usual test is to scratch the material with my fingernail. If the material dents and makes a smooth scrape-like mark when you scratch it, you're probably OK. If the material comes off under your finger nail in chalk-like form, or if the scratch mark isn't smooth, then the material is weathered and has suffered some damage.
Bill
Thanks I’ll try that