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I had solar installed last week. The past couple of days it has been raining so I went to my attic to check for any leaks. I didn't notice any leaks but I noticed the following:

  1. Mounting screws weren't on framing. One barely missed the rafter and another one doesn't seem to be long enough to be deep into it. Should I worry about the panels getting dismounted with strong winds?

  2. What's up with all the nails? Was that to secure the shingles? Are these sealed? Should I worry about leaks?

mounting screw barely missing the stud

mountain screw not deep enough in the stud

lots of nails

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  • There are no studs in a roof. Have a look at a basic framing diagram.
    – isherwood
    Mar 30, 2023 at 13:38
  • 1
    Can anyone describe the roof framing strategy we see here? It's completely unfamiliar to me. Why are there primary and then secondary purlins under a wood deck? That's something I'd expect to see for a steel roof, but with just one layer of purlins. And why do we see what appears to be a triple one-by top plate?
    – isherwood
    Mar 30, 2023 at 15:22
  • Please post pictures of the roof and a more distant shot of the rafters. Sep 17, 2023 at 10:00

3 Answers 3

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Highly unlikely the nails are from the solar installation. They probably are part of the original construction. Not leaking...no problem.

The screws anchoring the solar panels do not need to be into the roof rafters/ trusses, only into the roof decking. Again, not leaking...no problem.

In the event of high winds, it is more likely that the anchoring point on the panels would fail before the screws pull out. Should the winds be so great that the force on the panels cause all the screws or mounting points to fail, you will have much more damage from other sources, such as wind driven debris and the panels will be a secondary concern. ( This after 6 hurricanes and 1 no-name storm of experience)

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    I generally agree, but do installers really rely solely on the roof sheathing? That surprises me.
    – isherwood
    Mar 30, 2023 at 13:41
  • generally the weight is less than 2lbs/ sqft, and the dimensions aren't designed specifically for 24 or 16 inch spacing. Anchoring into heavy framing is not a requirement for proper performance, nor a structural issue. So it isn't considered.
    – RMDman
    Mar 30, 2023 at 13:52
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    @RMDman it's not just the weight. Solar panels are often vertically offset from the roof, so wind lift can be a factor.
    – Huesmann
    Mar 30, 2023 at 14:44
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    Wind lift was my primary concern.
    – isherwood
    Mar 30, 2023 at 15:19
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Quite simple; the screws should be in the rafters. Look at the size of the screws and the thickness of the decking which is normally only 5/16”. It is the lifting force of the panels by strong wind which will pull out the screws through the decking. For my roof I needed to send the research of the screws through my metal rafters to the permitting dept.

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Part of the answer.

It looks you have asphalt shingle roofing. The nails are holding them down. If done properly, the shingles overlap the nail, so there is no issue with leaks.

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