Solar panel mounting on rubber roof

Put 480 watts on my rubber roof, but used Dicor self leveling below the brackets and above. Made wider brackets for a larger footprint also ... no problems with my roof.

I don't think VHB or any other 2-sided tape is good for rubber roof on its own. You would have to drive a few screws to anchor it properly to the plywood. And when you use the screws, it doesn't matter whether there is a VHB under the bracket foot or a sealant like Dicor. I think Dicor would be better, because it seals the holes.

I really depends upon what is underneath the rubber. My roof had some areas with metal framing and in between it is mostly 1/4" thick luan material. I ended up fabricating a metal frame from 1.25" angle aluminum so I could screw into the metal framing sections at the sides of the roof using stainless self-tapping screws. The same frame will holds two panels and has room for a third.

I was much less worried about leaks than having the panels come off the roof and tear up everything in the process.

Another mounting option if you have 1/2" thick material on the roof is a well-nut. It will provide a stronger fastening than screws.

VHB is an option if you use a special pre-cleaner and the rubber is firmly attached to the material underneath at all points and not only at the edges.

3M adhesive strips, permanent seal of bracket to rubber roof
screws thru bracket achor everything to the underlying wood/luan
keeps the rubber roof from seperating from the underlying structure

Almot wrote:
Yes, this is the list that I talked about. Some designs won't work for you, but Mr Wizard's mounting should.

http://i298.photobucket.com/albums/mm251/Mr__Wizard/IMAG0103.jpg

Doesn't have to be exactly like this. Mr Wiz probably used 2x2 aluminum angle. You can make brackets longer, so that they would attach to the roof with 2 or 3 tapping screws each, or you can make them higher, say, 4" tall, of 3x4 or 4x4 angle. Into the side of the panel the brackets are attached with 1/4" machine screw - either rivet nut in the panel frame, or just a screw and nut. Don't know what is that black stuff under the brackets, put roof sealant there anyway. If you use #10 screws in the roof, it is desirable - though not absolutely necessary - to drive them in the studs, they are usually on 16" centers though might be on 18". Or a well nut through the deck plywood, then it has to be not on the stud. Plenty of options.

westend wrote:

Ron3rd wrote:

westend wrote:
If you use Eternabond Double-Stick tape over each hole, while you are fastening, the tape will seal each screw hole.

That's a very good idea. I've used EB before but did not think of using it in that way.

Here you can see the video:Eternabond video. I actually used Eternabond Webseal and it performed just like the video depicts, covering the screw head and filling the hole as I turned the fastener, amazing stuff!

That is one of the coolest things I have seen!

Yes, this is the list that I talked about. Some designs won't work for you, but Mr Wizard's mounting should.

http://i298.photobucket.com/albums/mm251/Mr__Wizard/IMAG0103.jpg

Doesn't have to be exactly like this. Mr Wiz probably used 2x2 aluminum angle. You can make brackets longer, so that they would attach to the roof with 2 or 3 tapping screws each, or you can make them higher, say, 4" tall, of 3x4 or 4x4 angle. Into the side of the panel the brackets are attached with 1/4" machine screw - either rivet nut in the panel frame, or just a screw and nut. Don't know what is that black stuff under the brackets, put roof sealant there anyway. If you use #10 screws in the roof, it is desirable - though not absolutely necessary - to drive them in the studs, they are usually on 16" centers though might be on 18". Or a well nut through the deck plywood, then it has to be not on the stud. Plenty of options.

Wow lots of great ideas Thanks People.

Look at some of the solar installs documented in this thread:


Lot's of solar installs with lots of pictures.



You will get lots of great ideas from looking at these.

Ed

Ron3rd wrote:

westend wrote:

Ron3rd wrote:

westend wrote:
If you use Eternabond Double-Stick tape over each hole, while you are fastening, the tape will seal each screw hole.

That's a very good idea. I've used EB before but did not think of using it in that way.

Here you can see the video:Eternabond video. I actually used Eternabond Webseal and it performed just like the video depicts, covering the screw head and filling the hole as I turned the fastener, amazing stuff!

Nice info westend. Thanks for passing that along.

You're welcome.

FWIW, my method of fastening through an aluminum roof was to place the Eternabond tape and a couple of beads of Geocel sealant under aluminum channel pieces and screw directly into the roof trusses. I used three 1 1/2" #12 stainless steel screws for each channel. Since I have a tilting mount, I established three of these channel mounts to support the module.

Check the list of installs on the forum, don't remember the link. 3M VHB tape is for fiberglass roofs and only if they are flat. On rubber everybody is using brackets on #10 tapping screws into plywood (or well nuts if you prefer) and plenty of roof sealant under the bracket and over the screw heads.