Mounting solar panels on fiberglass roof

[Vach]

Two years ago I mounted a solar panel on my travel trailer rubber roof using 3M VHB tape. It worked great. I have now bought a Winnebago Aspect with a fiberglass roof. Is the same tape the right one to use? Any recommendations are appreciated. Thanks

[Vach]

Thank you !

[westend]

Forum member's solar installations by Renoman69.

[Vach]

I had at one time found a sticky of solar installs on here. I searched all over again this morning and can't find them. Any ideas where to look? Thanks.

[westend]

Vach wrote:
I'm kinda old school too. The tape worked great previously but wouldn't mind a fastener. Would have to be close to 4" long to hit a wood ceiling joist. Hard to get screws that long plus they don't have a lot of hold power. Anyone use lag bolts? They seem a little extreme for the roof and joists.

IIRC, I used 1 1/2" #10 stainless metal screws, through the .125" aluminum mount, through a layer of Eternabond tape, through the aluminum skin, and into the wood rafter. I then sealed around the mounts with Proflex. The holes were drilled.

Here's an interesting video from Eternabond showing what happens when a screw is turned through the tape: Instant screw sealing

[Shadow_Catcher]

We have a 185W 66 cell high voltage panel mounted on a Filon roof on our teardrop. The prospect of it coming off in traffic made me shudder. I called 3M and talked with an engineer for the better part of an hour and he calculated how much contact area and which VHB tape to use. I used their cleaner and followed cleaning recommendations when installing. This has withstood wind speeds well in excess of 120mph.
Yes it can be done and Yes it works well, BUT you had better do it correctly.

[Vach]

I'm kinda old school too. The tape worked great previously but wouldn't mind a fastener. Would have to be close to 4" long to hit a wood ceiling joist. Hard to get screws that long plus they don't have a lot of hold power. Anyone use lag bolts? They seem a little extreme for the roof and joists.

[westend]

RoyB wrote:
I think I am going to mount some aluminum UNISTRUT type cross sections attached to the side of the trailer just below the roof. I have mounted things in this area already and has proven to be very strong etc. Nothing will touch the roof area. All of the cabling etc will follow the unistrut to a electrical mounting box on the side of the trailer and go thru the wall at that point.

In my case the VALANCE CURTAINs that go around my whole POPUP interior will hide all of my cabling that will be inside wire management units (LOWES)

My unistrut going across the roof will allow me to use quick disconnect hinges so I can remove the panels to place on the ground if needed to stay in the high sun...

Haven't got it all on any paper yet but think this is going to the best way for me to mount my three or four 120WATT size SOLAR panels on my POPUP ROOF.

Mounting the solar panels on top of the unistrut will have a couple of inches between the panels and the roof surface.

The unistrut mounting nuts will slide the whole width of the roof making for a great and secure install.

Roy Ken

Great idea! With unistruts you'll be easily able to install a tilt arm/s, also, should you decide tilting is in your best interests. I also led the solar module wiring through the wall. I used conventional plastic EMT which allowed an easy scheme for mounting a J box on the top.

[RoyB]

I think I am going to mount some aluminum UNISTRUT type cross sections attached to the side of the trailer just below the roof. I have mounted things in this area already and has proven to be very strong etc. Nothing will touch the roof area. All of the cabling etc will follow the unistrut to a electrical mounting box on the side of the trailer and go thru the wall at that point.

In my case the VALANCE CURTAINs that go around my whole POPUP interior will hide all of my cabling that will be inside wire management units (LOWES)

My unistrut going across the roof will allow me to use quick disconnect hinges so I can remove the panels to place on the ground if needed to stay in the high sun...

Haven't got it all on any paper yet but think this is going to the best way for me to mount my three or four 120WATT size SOLAR panels on my POPUP ROOF.

Mounting the solar panels on top of the unistrut will have a couple of inches between the panels and the roof surface.

The unistrut mounting nuts will slide the whole width of the roof making for a great and secure install.

Roy Ken

[pianotuna]

Hi,

I agree with Westend.

[westend]

Yes, and the tape should have a better bond than to EPDM.
I'm still too old school and prefer a fastener into something structural but I can sure understand not wanting to make any holes in the roof.