Forum Discussion

1L243's avatar
1L243
Explorer II
Jan 22, 2021

Installing Solar

My 500 watt system of 5 panels will be on order soon. I have watched several install videos, almost all videos show the installer mounting the solar panel brackets by screwing into the roof. Only one made any mention of looking for trusses to screw into. My roof has 3/8" plywood sheathing. Is it necessary to find a truss or is screwing in the sheathing acceptable? Panels can be placed more precisely if you don't have to hit a roof truss.
  • CA_Traveler's avatar
    CA_Traveler
    Explorer III
    Jan 23, 2021
    1L243 wrote:
    The problem is finding aluminum L brackets. The Z brackets are easy to find L brackets not so easy.
    Just the opposite as HD, Lowes and hardware stores carry aluminum angle. Very easy to cut and drill.
  • 1L243's avatar
    1L243
    Explorer II
    Jan 23, 2021
    The problem is finding aluminum L brackets. The Z brackets are easy to find L brackets not so easy.
  • BFL13's avatar
    BFL13
    Explorer II
    Jan 23, 2021
    Meanwhile, I was taking a jab at the idea of Z brackets. I agree with using two pieces so you can get the panel off and leave the bottom bracket still attached to the roof. Hope the OP figures it all out! :)
  • n0arp's avatar
    n0arp
    Explorer
    Jan 23, 2021
    BFL13 wrote:
    jshupe wrote:
    Jay58 wrote:
    Mine are screwed into 3/8 plywood thru a 6 inch long aluminum angle 2x2 with 5200 sealant/adhesive to glue down and seal fastener holes. Wires were attached to roof with eterna-bond tape ( no screw required)


    No plans to ever remove them!


    Not until you have to when trouble shooting the wiring some day! It can happen the trouble is underneath by the junctions that you can't get at with the panel in place.


    Again, I was taking a jab at the 3M 5200 that Jay58 used. It's a permanent bond that would tear apart the rubber roof and plywood before it would ever give. It's mostly used for bonding under the water line on boats and will rip apart a fiberglass hull before it fails. I used plenty of it on my offshore boat.
  • BFL13's avatar
    BFL13
    Explorer II
    Jan 23, 2021
    jshupe wrote:
    Jay58 wrote:
    Mine are screwed into 3/8 plywood thru a 6 inch long aluminum angle 2x2 with 5200 sealant/adhesive to glue down and seal fastener holes. Wires were attached to roof with eterna-bond tape ( no screw required)


    No plans to ever remove them!


    Not until you have to when trouble shooting the wiring some day! It can happen the trouble is underneath by the junctions that you can't get at with the panel in place.
  • n0arp's avatar
    n0arp
    Explorer
    Jan 23, 2021
    pianotuna wrote:
    Jshupe,

    Mine are aluminum angle screwed to the roof. I used just 3 screws per side. They are still in place.


    No issue with that. I've used 2x2 aluminum angle screwed to the roof (with sealant, as I'm sure you're using) as well.

    Did I miss something - why are you telling me specifically?

    Edit - if it was due to my quoting Jay58, I was referencing his use of 3M 5200. It forms a permanent bond that will tear the rubber and plys apart before it gives. Wonderful stuff - for use under the waterline on a boat.
  • time2roll's avatar
    time2roll
    Nomad
    Jan 23, 2021
    I used #10 stainless drywall screw and Dicor just into the plywood at random.

    I did drill a small pilot hole so the screw would penetrate cleanly.

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