Securing Solar Panels to the Roof of an RV

Topic: Securing Solar Panels to the Roof of an RV (Read 1683 times) previous topic - next topic

Securing Solar Panels to the Roof of an RV

February 09, 2012, 03:25:27 pm

The RV forums - including this one - have many reports of installing solar panels to the roofs of RVs using some of the modern tape technologies. It seems to be common practice on fiberglass roofs as well as aluminum roofs. But the surface of most fiberglass roofs isn't the fiberglass but gel coat or paint which seems to me to be substantially less secure than the fiberglass shell itself.

Still... several FT owners have reported using tape (or of having an installer use tape) for the panels and the wiring harnesses.

Are they sanding through the gel coat? I'm about to pull the trigger on some solar panels and would like to nail down the best method for installing them before I do it.

Craig

Re: Securing Solar Panels to the Roof of an RV

Reply #1 – February 09, 2012, 04:59:47 pm

My experience with industrial grade 3M VHB tapes leads me to believe you could mount the panels with the tape and then suspend the coach from the panels without pulling either tape or gelcoat loose. Bearing in mind that the gelcoat is chemically linked to the resin in the fiberglass I wouldn't worry about the strength of that bond either.

I know "tape" sounds sketchy but this is some bull goose stuff. Check out the video, the tape segment is about two minutes into it.

3M VHB tape final

Chuck

Re: Securing Solar Panels to the Roof of an RV

Reply #2 – February 10, 2012, 06:26:26 am

Hi Craig,

I'm also about to pull the trigger on solar panels, but I wouldn't want them permanently mounted - might be an issue should you need to replace one, or if there came a time when you wanted to remove them and use them on something else. As mentioned elsewhere, an air space below provides a cooling effect. Then there is the aspect of tilting the modules to catch the winter sun, which wouldn't be possible if the panels were bonded to the roof.

That tape would no doubt hold them there, though. Adhesives have come a long way in the last few years.

Steve

Re: Securing Solar Panels to the Roof of an RV

Reply #3 – February 10, 2012, 03:33:36 pm

I've used a "RV Roof Sealing Tape" like this: EternaBond WebSeal to seal holes, tape over wire runs, etc. It holds extremely well and if it has to come up, you can get it up. There is a double sided tape that might work for you. Here's a link to some videos for RV repair as well: Roof Leak Repair Products & Sealing Tape | EternaBond®

Re: Securing Solar Panels to the Roof of an RV

Reply #4 – February 10, 2012, 04:47:26 pm

as reported a few times before on this tape issue, I have mine held on with 3m tape and not had a problem. AM Solar whose business is solely rv installs has been using this stuff for years and Greg said no problems at all. Why use mechanical fasteners and screw up the roof. This stuff works well and is a non issue for me, and should you ever want to remove them it can be done safely too.
John H

Re: Securing Solar Panels to the Roof of an RV

Reply #5 – February 10, 2012, 05:06:00 pm

Removing the 3M foam tapes can be done by cutting through them with a fine wire. I would expect that anyone mounting solar panels would not mount them directly to the roof, rather would use an aluminum C channel taped to roof, panels bolted to channel. Would give some ventilation and make for easy removal if necessary.

Chuck

Re: Securing Solar Panels to the Roof of an RV

Reply #6 – February 10, 2012, 05:21:24 pm

Mounted mine on a c style stand with the 3M tape from AM solar over 10 years ago. The next owners still have them on.... great stuff.

Re: Securing Solar Panels to the Roof of an RV

Reply #7 – February 10, 2012, 06:11:02 pm

You don't mount solar panels to the roof. You mount solar panel BRACKETS to the roof. Then you attach the panels to the brackets via wingnuts so you can attach legs if you want to angle for more sun. My solar panels connect together with simple extension cords so if I want or need to, I can remove them from the roof for ground mounting away from the motor home with the only downside being the number of extensions I have with me to connect to them.

Re: Securing Solar Panels to the Roof of an RV

Reply #8 – February 10, 2012, 08:13:44 pm

twig, I think most people realise you mount the brackets to roof, not the panels and this fact was a given.
John H

Re: Securing Solar Panels to the Roof of an RV

Reply #9 – February 11, 2012, 02:21:09 pm

Quote from: John Haygarth – February 10, 2012, 08:13:44 pm

twig, I think most people realise you mount the brackets to roof, not the panels and this fact was a given.
John H

Yup.

Craig

Re: Securing Solar Panels to the Roof of an RV

Reply #10 – February 11, 2012, 08:50:58 pm

Then I guess I am confused about the use of tape. Why make a simple job complicated? Solar panels have 4 corners. 4 brackets mounted to the roof using caulk. Panels to the brackets. Why the tape?

Re: Securing Solar Panels to the Roof of an RV

Reply #11 – February 11, 2012, 09:40:49 pm

The tape is airline tape. It is good to 300 mph or some such speed and heat and cold and is very easy to apply. It fits the bottom of the bracket and it goes no with no effort or mess.

Re: Securing Solar Panels to the Roof of an RV

Reply #12 – February 11, 2012, 10:09:52 pm

Quote from: John S – February 11, 2012, 09:40:49 pm

The tape is airline tape. It is good to 300 mph or some such speed and heat and cold and is very easy to apply. It fits the bottom of the bracket and it goes no with no effort or mess.

And no holes in the top of the coach to act as potential leaks.

Craig

Re: Securing Solar Panels to the Roof of an RV

Reply #13 – February 11, 2012, 11:02:44 pm

twig, you do not use caulk to hold the bracket that is what the strong tape is for. The caulk (levelling rv type) is just to protect the tape from weather and make a nice smooth finish
John

Re: Securing Solar Panels to the Roof of an RV

Reply #14 – February 12, 2012, 11:23:30 am

It appears in my case I will need to drill holes for the brackets. I redid the roof this past summer with an EPDM coating, and while I'm sure the tape will hold, the coating may not under the stress while in motion. Would hate to see a panel land on the road behind me and cause a wreck.

Steve

Re: Securing Solar Panels to the Roof of an RV

Reply #15 – February 12, 2012, 12:01:42 pm

Quote from: Merle Hench – February 12, 2012, 11:23:30 am

It appears in my case I will need to drill holes for the brackets. I redid the roof this past summer with an EPDM coating, and while I'm sure the tape will hold, the coating may not under the stress while in motion. Would hate to see a panel land on the road behind me and cause a wreck.

Steve... You might consider sanding the coating down to the f/g. The brackets can have a relatively small footprint. I would do almost anything to avoid putting more holes in the roof of our coach. It doesn't leak now (at least I have not been able to find any evidence of leaking) and I don't want to push my luck too far.

Craig

Re: Securing Solar Panels to the Roof of an RV

Reply #16 – February 13, 2012, 10:50:10 am

Dunno Craig... might create a leakpoint in trying to remove the coating in just that small area where the bracket attaches. Six of one and a half dozen of the other. AM Solar offers Dicor sealant for the screws/screw holes; I've been sealing everything with 3M 5200 marine sealant (great stuff - works even below the water line).

I guess part of me still isn't comfortable without some kind of mechanical fastener. I saw the videos, but still uneasy.

Steve

Re: Securing Solar Panels to the Roof of an RV

Reply #17 – February 13, 2012, 11:49:39 am

Steve, the bracket footprint is around 3" x1" so why not just use a very sharp scraper/putty knife and remove the EDPM stuff just there to get down to the gel coat. Should be easy, then tape and caulk down the bracket. The panels are very safely held on with tape. Greg(owner at AMSolar) has never had a panel fly off he said holding it this way. Have faith in the method. My 4 are on this way and having driven over highways/byways and thouands of KM of Mexican roads are still sitting there and no sign of movement.
John H

Re: Securing Solar Panels to the Roof of an RV

Reply #18 – February 14, 2012, 08:19:14 am

Thanks John. Guess it's time to give Greg a call. Have enough holes in the roof already.

Steve

Re: Securing Solar Panels to the Roof of an RV

Reply #19 – February 14, 2012, 10:58:53 am

Steve, the tape you can buy at a local Auto stre. It is 3M and used for applying the plastic trim to a car etc. It is around $15-20 for a 1/2" wide roll and comes in a plastic package. A good store selling auto paint ,striping etc will have it and it has a red colour protective film.
John

Re: Securing Solar Panels to the Roof of an RV

Reply #20 – February 21, 2012, 08:25:27 am

Quote from: John Haygarth – February 14, 2012, 10:58:53 am

Steve, the tape you can buy at a local Auto stre. It is 3M and used for applying the plastic trim to a car etc. It is around $15-20 for a 1/2" wide roll and comes in a plastic package. A good store selling auto paint ,striping etc will have it and it has a red colour protective film.
John

Make sure you're getting the right stuff! The tape you want has a foam core, it's maybe 1/16" thick. I'm thinking I paid more on the order of 50.00 a roll for it at the paint shop. A visit to 3M website might be in order.

Re: Securing Solar Panels to the Roof of an RV

Reply #21 – February 21, 2012, 09:19:08 am

Agreed. The standard double-sided foam tape you buy at the local store is not up to the task.

The vinyl trim I applied to the sides of my fridge had a foam tape with the red protective film. While I was applying it, I tried to lift it to reposition it, and it pulled the walnut veneer from the panelling. That's a different animal.

Still inclined to go with mechanical fasteners at this point. As long as the holes are properly sealed, I have no concerns about anything coming loose. But that's just me...

Steve

Re: Securing Solar Panels to the Roof of an RV

Reply #22 – February 21, 2012, 09:44:45 am

Steve, since you applied an EPDM coating, you definitely want to go with mechanical fasteners. The interlaminary strength of EPDM to Gel Coat is inadequate to secure the panel brackets. Also if you cut or sand off the EPDM, you increase the chance of highway speed air getting under the EPDM causing delamination.

Re: Securing Solar Panels to the Roof of an RV

Reply #23 – February 21, 2012, 10:06:54 am

my 2 cents---if after removing the |EPDM and taping on the brkts you then put some leveling caulk over the whole area and brkt this would stop any "wind" getting under the coating. The 3M tape I got at Napa store and was around $18 and I used it to fasten on my wind deflecters I put in front of Panels to help with (while travelling) wind getting under them. They weigh about 4lbs each and must get quite a buffeting while driving and have not and do not show any signs of movement at all, so the tape and caulk is definitly doing its work. AM Solar techs saw them and figured they are a great idea to stop possible wind etc noises while driving. They DO NOT increase any heat under panels while parked as I raise the panels and even if left flat they are about3" in front of the brkts so air is free to move around. Sounds like the tape you used that pulled the veneer off maybe the one!! It is used by body shops to hold on side mldgs etc on vehicles.
John H

Re: Securing Solar Panels to the Roof of an RV

Reply #24 – February 21, 2012, 12:11:57 pm

John,
Do you have any pictures and or links to the wind deflectors? That sounds like a very good idea to me and have been wondering about what products might be out there that would fill the bill... Still a ways from adding the solar, but always looking down the road

Don

Quote from: John Haygarth – February 21, 2012, 10:06:54 am

my 2 cents---if after removing the |EPDM and taping on the brkts you then put some leveling caulk over the whole area and brkt this would stop any "wind" getting under the coating. The 3M tape I got at Napa store and was around $18 and I used it to fasten on my wind deflecters I put in front of Panels to help with (while travelling) wind getting under them. They weigh about 4lbs each and must get quite a buffeting while driving and have not and do not show any signs of movement at all, so the tape and caulk is definitly doing its work. AM Solar techs saw them and figured they are a great idea to stop possible wind etc noises while driving. They DO NOT increase any heat under panels while parked as I raise the panels and even if left flat they are about3" in front of the brkts so air is free to move around. Sounds like the tape you used that pulled the veneer off maybe the one!! It is used by body shops to hold on side mldgs etc on vehicles.
John H

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