Mounting solar on rubber roof

[Salvo]

What's the best method in securing solar on a rubber roof trailer? This will be a flat install. Z-brackets are already ordered, but if there's something better...

It is for my son-in-law's new toy hauler.

Sal

[ken_white]

Salvo wrote:
Thanks, those were the exact ones I'm been looking at. They are not neoprene though, but rubber. I got 3/8" plywood roof. They will fit. I just don't like the thought of drilling a 1/2" hole for a 1/4" screw.

You use 2 per bracket?

I don't think there's any issue with the styrofoam insulation compressing when torquing down the well nut.

McMaster also carries them.

Sal

They are actually made of Cloroprene rubber, which is neoprene.

I used two bolts per mounting bracket (angle aluminum) for my 190 watt panels on my other 5th wheel and one bolt per bracket for the 50 watt panels on my truck camper due to size.

McMaster is normally my first choice for hardware, but Grainger is right down the road if I need it quick.

🙂

[Salvo]

Thanks, those were the exact ones I'm been looking at. They are not neoprene though, but rubber. I got 3/8" plywood roof. They will fit. I just don't like the thought of drilling a 1/2" hole for a 1/4" screw.

You use 2 per bracket?

I don't think there's any issue with the styrofoam insulation compressing when torquing down the well nut.

McMaster also carries them.

Sal

ken white wrote:


I used these -> 1/4-20

[ken_white]

Almot wrote:

Salvo wrote:
A couple used well nuts or molly bolts. This attachment is more secure, especially when no rafters are available. Can the styrofoam insulation behind the plywood inhibit or degrade this attachment method?

Never tried. What - I'm afraid - may happen is that after you've fastened it and the rubber had forced its way into the foam, the foam remains under pressure and will give in some more, with time. So it might need more tightening later.

You might be correct, my roof did not have a styrofoam backer, it had regular insulation behind the plywood roof.

I did check my bolts at the beginning of every season when I checked my roof, and did snug them if needed.

[ken_white]

Salvo wrote:
Ken- what size thread did you use? Perhaps 10-32?

Where did you purchase them?

Sal

I used these -> 1/4-20

You just need to make sure the grip length (range) is sufficient for your roof.

[Almot]

Salvo wrote:
A couple used well nuts or molly bolts. This attachment is more secure, especially when no rafters are available. Can the styrofoam insulation behind the plywood inhibit or degrade this attachment method?

Never tried. What - I'm afraid - may happen is that after you've fastened it and the rubber had forced its way into the foam, the foam remains under pressure and will give in some more, with time. So it might need more tightening later.

[Salvo]

Ken- what size thread did you use? Perhaps 10-32?

Where did you purchase them?

Sal

[mena661]

Looks like I'll go with well nuts and L brackets. Thanks all (Salvo).

[ken_white]

I used neoprene well-nuts for my previous 2 installs and will use them again for my new 5th. Make sure the roof area is clean where they get inserted so they don't spin and then apply Dicor overlapping the well-nut edge and roof area.

[Salvo]

Looking at all the installs, it appears, most people use screws to secure brackets to roof. A couple used well nuts or molly bolts. This attachment is more secure, especially when no rafters are available. Can the styrofoam insulation behind the plywood inhibit or degrade this attachment method?

Bill Rhino has a good video installing a panel with z-brackets. It doesn't look like an optimum design. You can't remove the panel without removing the roof screw & bracket. There's not much of an air gap between roof & panel either.

Sal

[SCVJeff]

L-Bracket

[Almot]

Just it make it clear, if you look at Mr. Wiz photos - he is talking Z brackets - but what he has is L-brackets, both his new ones and those from previous owner. I do think this is better than Z brackets, unless Z is so high that you can get to the nut/head under the panel and in the crevice of the frame. But hey, there are many ways to skin this cat...

[westend]

A stud finder will usually locate any fasteners that are in the plywood. That should indicate the rafter locations. I knew that my vent opening was located on the 16" spacing of the rafters so I measured back from that.
I have three parallel aluminum channels that are each attached across three rafters. Each channel has 3- SS 3", #12 screws. I also put a bead of Proflex sealant under each channel. The frame of the solar module is attached to the three aluminum channels with an intermediate aluminum angle piece.

[MrWizard]

as far i'm concerned ... YES it is

i have no idea how you can verify, where the rafters are in a covered roof
or that the dimensions of the panels will allow you hit rafters with all '4' mounts
IF you new the rafter spacing and could verify a starting point and laid down full length ROOF strips/mounts attached to the roof at the correct spacing, then attached the 'Z' brackets to the strips ???

[mena661]

MrWizard wrote:
we have a rubber roof over the OEM fiberglass
under the roof is plywood

So just drilling into just the plywood is ok? I'm kinda piggybacking on Salvo's thread as I need to know this too.