wireing through metal roof, and wiring code

davidwillisdavidwillis Solar Expert Posts: 104 ✭✭
I am getting ready to install my solar panels and wiring. I am installing 8 panels on the roof of a shed with a metal roof. It has 3/4 plywood on top of trusses, tar paper, then the metal roof.

I was thinking about just drilling a hole and putting a threaded pvc pipe through the roof with a gasket (when I tighten the top fitting on it will clamp onto the roof). Then when all the wiring was done I would just fill the top of the pipe with silicone. However this is going to be inspected by an inspector, and I am not sure that will pass. Also once inside, does the wiring need to be in a conduit?

Thanks

Comments

  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: wireing through metal roof, and wiring code

    My personal preference is to not put holes in roofs if possible. Run the conduit over the edge and bring it in through the gable end or eave. That way water can not stand around the penetration and eventually work its way through. Normally wiring "not accessible" does not need to be in conduit. That usually means inside a wall, attic, basement, or crawl space only needs to be fastened down. This does not hold true everywhere.

    As for what will meet code and pass inspection where you are, only your AHJ knows for sure.
  • davidwillisdavidwillis Solar Expert Posts: 104 ✭✭
    Re: wireing through metal roof, and wiring code

    Thanks

    I guess it would be easy enough to run a conduit over the side, but how would I seal the conduit so water would not just run through it? And how would I go through the wall?
  • westbranchwestbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: wireing through metal roof, and wiring code

    take 2 90 DEGREE elbows and a short piece of conduit to 'FLIP' the open end so that it points down
     
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  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: wireing through metal roof, and wiring code
    Thanks

    I guess it would be easy enough to run a conduit over the side, but how would I seal the conduit so water would not just run through it? And how would I go through the wall?

    There is conduit design to be used outdoors. PVC type is literally glued together. There are through fittings for walls and rubber-clamp seals for wires. You can have a fun day at your local hardware and/or electrical supply looking at all that's available where you are. And ask the people that run those places what they recommend. Like I say, what you use is going to depend on what meets code where you are. Just because I can get away with PVC looping down and up and sealed at the wall with exterior silicone caulk doesn't mean your inspector would approve. That's the trouble with building & electrical code questions: the rules aren't the same everywhere.
  • TnAndyTnAndy Solar Expert Posts: 249 ✭✭✭✭✭
    Re: wireing through metal roof, and wiring code

    I run a PVC conduit up, put a roof flange on the roof side screwed down and siliconed around, then top the conduit off with a weatherhead designed to do just that.....keep water out. You can get them in any conduit size from about 3/4" on up.


    Flange:

    (Most any metal roofing dealer carries these)

    flashing-boot.jpg

    Weather head: ( anyplace that sells electrical supplies)

    PVPSEC.jpg&w=150&h=150
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