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Thread: PV modules hanging past eaves

  1. #1
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    PV modules hanging past eaves

    I'm doing a grid tie-in on a solar array. The guy we had installing the modules on the roof let them hang over the edge about 10 inches. Are there any code violations with this?

  2. #2
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    FWIW, you guys will be really doing the installer a huge favor if you can confirm it is not a violation. My boss has got him moving that stuff right now. I think it's sloppy, but I don't want to see him punished like that. Another employee says a building inspector told him it's not legal because of winds. I don't know.

  3. #3
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    Quote Originally Posted by ike5547 View Post
    FWIW, you guys will be really doing the installer a huge favor if you can confirm it is not a violation. My boss has got him moving that stuff right now. I think it's sloppy, but I don't want to see him punished like that. Another employee says a building inspector told him it's not legal because of winds. I don't know.
    This is pretty deep in the weeds and totally subject to interpretation. My feeling is that the installer would need to have a PE sign off of the structural design in order for this to meet the building code—assuming, that is, that he used the standard expedited permit process when he pulled his permits. Basically, this installation practice—beside looking bad—exposes the array to higher than expected wind loads. Maybe the structural system can support these additional loads, maybe it can't. The mounting system vendor design tables likely do not cover this installation practice; the expedited permit process definitely does not.

    Anyway, if I was the AHJ, I'd say show me your stamped engineering drawing or move the array. Most of the AHJs in the country probably wouldn't know the difference. But in CA, they've probably seen it all before and are trained on these details.

  4. #4
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    An AHJ would be right to have such an installation reviewed by a civil engineer. I’ve seen quite a few overhanging arrays over the years. Some have no problem yet, some get the wind under them and are pealed off becoming dangerous projectiles.

  5. #5
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    A less serious, but potentially still meaningful problem, is water runoff spilling over the gutters. That could be just a mere annoyance of streams of water hitting people where they walk or creating noise on another roof or surface, or it could be more serious in compromising the proper drainage designed for the roof or property.

    I completely agree with the other postsabout wind.
    Last edited by jaggedben; 02-14-17 at 11:06 PM.

  6. #6
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    Quote Originally Posted by ike5547 View Post
    I'm doing a grid tie-in on a solar array. The guy we had installing the modules on the roof let them hang over the edge about 10 inches. Are there any code violations with this?
    I presume this is in California? My knee-jerk response is that it is indeed a violation of fire code, and particularly with respect to access pathways on pitched roofs. In addition to that, I share the same sentiments that Solar Pro suggested on multiple levels.

    http://osfm.fire.ca.gov/pdf/reports/...cguideline.pdf

  7. #7
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    If it restricts firefighters from putting a ladder up that would probably be a problem for the owner when the building is on fire. They would not put a ladder up on the overhang area of modules. There are code requirements and then there are things the code might not address that are just obvious bad ideas. Not that I have not seen dumb things done and justified by saying, “Hey, it meets code."

  8. #8
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    Quote Originally Posted by Anode View Post
    I presume this is in California? My knee-jerk response is that it is indeed a violation of fire code, and particularly with respect to access pathways on pitched roofs. In addition to that, I share the same sentiments that Solar Pro suggested on multiple levels.

    http://osfm.fire.ca.gov/pdf/reports/...cguideline.pdf
    *In the interest of accuracy, note this link is not the current fire code in CA. Good point though.

  9. #9
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    Quote Originally Posted by pv_n00b View Post
    An AHJ would be right to have such an installation reviewed by a civil engineer. I’ve seen quite a few overhanging arrays over the years. Some have no problem yet, some get the wind under them and are pealed off becoming dangerous projectiles.
    Remember, sometimes the uplift forces are greatest towards the center of arrays as opposed to the edges.

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