Solar install with sprayfoamed roofline – risky?
I’m on the fence regarding moving forward with a solar install.
Here’s my situation:
– Home built in 2022.. Reasonably tight, around 1.5 ACH.
– Roofline and gables are insulated with a bunch of sprayfoam. I think closed-cell but not sure. When you’re in the attic, you can’t see the rafters at all.
– Location: Massachusetts about a mile off the coast.
I have two concerns:
1) Water ingress. If the solar install is imperfect and results in a leak, I’m worried the foam will conceal the leak. I could imagine that over time (especially with our windy winters) the hardware might shift enough to compromise the waterproofing.
2) Rafter locations. Since they’re a bit hidden inside, are the roofers going to have to remove a bunch of the spray foam (compromising the insulation) to verify they hit the rafters?
Are my concerns overblown? Has anyone else dealt with this situation, and if so, how did you alleviate your concerns?
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Replies
Regarding (1), you shouldn't consider seeing leaks in a roof a plus. It's much more important to put the roof together properly to avoid leaks in the first place. This "spray foam conceals leaks" concern comes up every now and then, and it's not something I think is worth worrying about. Put your efforts into proper flashing and sealing details.
Regarding (2), there are other ways to know if you're in a rafter or not. A very simple way is to just drive a nail -- the nail will go into the foam MUCH more easily than a rafter, so you'll know right away from the feel of driving the nail. Stud finders will also work in some cases (not always). I wouldn't worry too much about this either. Worst case, you could peel back some of the cap at the ridge and see the ends of the rafters, which might be immediately visible, but could be exposed easily by cutting out a narrow strip at the extreme edge of the topmost sheathing.
What I would do is to liberally apply elastomeric sealing compound at any/all roof penetrations to ensure good seals. I would also try to minimize how many attachment points there are for the frame supporting the solar panels, since fewer penetrations = fewer places that might leak.
If the solar installation is done correctly by a competant installer with good attention to details, I don't see any problems putting solar on your roof.
Bill
Thanks Bill, this is exactly the answer I was hoping for!
Is it fair to say you have asphalt shingles vs a metal roof?
Yes, asphalt shingles