Solar Install

[WarrenS65]

I'm installing solar panels on my Host Everest. Does anyone know if the roof will support using self drilling screws, or do I need to hit a crossmember?

[CaFordGuy]

I would suggest using Well Nuts. A very good grip in a thin roof and provides an extra measure of moisture sealing. I've installed several panels this way and they are very secure.

[WarrenS65]

OP here. Grit dog is right and the question was me trying to get my ducks in a row before I made holes in my roof. I never had any intention of attaching the panels with any adhesive/glue/tape.

Anyway, I finally got around to mounting my panels. I called Host a few weeks ago to ask where to find the the rafters and was told they attach the factory mounted panels to the frame at the outer edge of the camper and then the inner brackets they just screw into the 1/4" marine grade plywood under the rubber roof.

I'm almost done with my electrical upgrades and will post about the finished product in a few more weeks.

[jimh406]

The article says "adhesive" and "glue". No mention of tape.

Who knows what the glue or adhesive was. If you used the wrong type/size screw and went into a soft part of the roof those could fail as well. Not to mention the bracket could come undone with the wrong type screw/nut/washer.

Even the orientation/angle of the panel and where it was mounted could make a difference not to mention the speed of the vehicle traveling and the prevailing wind force.

[Grit_dog]

jimh406 wrote:


Nope, I'm one of those guys who points that that opinions aren't the same thing as facts even if the person posting is positive they are right. I trust that people will do their research to determine the best option for their situation.

For the record, I don't have a solar panel mounted on my TC, so your panel(s) will fall off way before mine will. 😉

Jim, ya missed the boat on this one...
First, this IS the OP "doing his research" and second, you either didn't think about this before responding, or maybe you have more knowledge here that you're just not sharing?
I don't see attaching something heavy that turns to a sail and experiences 100+mph winds with tape, to another "soft" surface that is glued down being a great, or even good idea.
Why is it a good idea to you? Honest question.

I've seen enough rubber roof membranes look like bed sheets buffeting on top of campers rolling down the road to be pretty certain that the bond between the roof and the membrane most likely isnt rated or even feasible to withstand constant force of trying to delaminate it from the roof.:R

[joeshmoe]

Here's one. Narrowly escaped.
There's another where 3 people were killed as a result of swerving to avoid flying panels. Any of the solar forums, you find at least a few people stories of avoiding flying panels.

The point is...don't do it.

https://www.solarquotes.com.au/blog/solar-panel-caravan-coroner-mb2475/

DOT or NHTSA will have the statistics you're looking for.

[trail-explorer]

joeshmoe wrote:
....begins to rightfully work itself loose and panels end up through the windshield of a minivan full of kids or worse, causing multiple vehicles to crash? It happens more often than you're willing to admit, obviously.

WHen did it happen?
I've searched all over the interwebs and don't see a single report of it happening.
Granted, I'm not one that would use VHB tape to attach panels to ANY roof material.

[jimh406]

joeshmoe wrote:
So you're one those guys who slaps or should I say "sticks" with tape, panels on a roof and calls it good?

Nope, I'm one of those guys who points that that opinions aren't the same thing as facts even if the person posting is positive they are right. I trust that people will do their research to determine the best option for their situation.

For the record, I don't have a solar panel mounted on my TC, so your panel(s) will fall off way before mine will. 😉

[joeshmoe]

So you're one those guys who slaps or should I say "sticks" with tape, panels on a roof and calls it good? Mine aren't going anywhere. Yes, use what you want to your own and others detriment.
How's it gonna feel when unbeknownst to you, your "right" tape job begins to rightfully work itself loose and panels end up through the windshield of a minivan full of kids or worse, causing multiple vehicles to crash? It happens more often than you're willing to admit, obviously.

There IS only one way to install panels--the safe and secure way. We're not talking about plastic moulding or fiberglass body trim.

[jimh406]

joeshmoe wrote:
**Do Not** use ANY kind of tape as a primary fastening device on a rubber roof to secure rigid framed panels.

All of the solar panels etc that are attached that way will probably all fall off at the same time. Seriously though, there is more than one way to attach solar panels.

Choose what you want. Tape is used to hold on body parts for vehicles and the right tape can work well no matter if it is solar panel or not.

[joeshmoe]

**Do Not** use ANY kind of tape as a primary fastening device on a rubber roof to secure rigid framed panels.

As mentioned, find studs to drill into. Look at using aluminum Unistrut as a base or frame. Your panel dimensions will not land exactly where the cross members are. A little pricy, but its WAY lighter than the steel version. It's easier to cut and work with and wont look ugly in a few years. I suppose you could even hit it with a coat of white paint to cut down on the little, extra heat absorption. Your choice.


I just added a three more panels to my array using the 2" tall version (only size available) Unistrut, self drilling (not self-tapping) stainless lag bolts, fender washers, 1.5" wide Eterna-Bond tape and Dicor lap sealant. We know Dicor is perfectly compatible with TPO and EPDM. Other sealants...mmm...maybe not. Plus, it's far more pliable to remove or to clean and reapply. Urethanes, like Sika are a little too good at adhering. I don't need that on the roof.

Properly clean and prep all surfaces (denatured alcohol, mineral spirits or sparing use of acetone and Scotch Brite pads work well).

Using a total of six 5/16" x 1.25" bolts, 1/4" pre-drilling all holes was necessary.

Next, cut roughly a 3" long x 1" Eterna-Bond tape and apply over all pre-drilled holes, noting location of hole. Be sure to press down hard across the entire strip of EB. Its pressure activated. Repeat these steps at all penetration points.

Next, Add a large dollop of Dicor onto EB tape.
Center and align corresponding Unistrut slot opening over noted pre-drilled holes. Press down. Allow Dicor to evenly compress and ooze out from under Unistrut.

Install fender washer on bolts. Preferably, using some kind of impact driver, locate hole with point of bolt and drive it in with moderate pressure. It'll just spin otherwise. Stop at about 3/4 way in and use a ratchet to finish by hand tightening. Note: Over tightening or using impact to fully drive bolt may result in stripping. Now, you have to start over. Don't do that.

Once all bolts are installed, apply Dicor to fully cover bolt heads and washers. Done.

Arrange and install panels using Unistrut cone-nut washers or whatever bracket fastening system you choose. The idea is to plan for expansion and only drill holes once. MUCH easier.

Anyone can drill holes, destroy their roof and randomly throw up a bunch of panels.

Somewhat related tip:
You may already know it, but try not to walk on your roof with shoes. I'd rather ruin a few pair of socks than forget to check and track a tiny rock or two. Or in my case, a metal shaving that burrowed itself into my shoe bottom then transferred into the rubber roof. So much so that I felt it might become a water intrusion point, so I put a piece of EB tape over it.

Good luck

[Camper_Jeff___K]

That tape is only as strong as what it's attached to. A screw into a roof member with a quality adhesive caulk works every time.

[deltabravo]

Ed_Gee wrote:
Avoid holes all-together by using Scotch 3M VHB double sided heavy duty tape - # 4950.

Using that on a rubber roof is a recipe for disaster!

[Ed_Gee]

I should have exempted rubber roof from my previous post. My concern is you having enough cross members in your roof to provide adequate mounting for solar panels.

[WarrenS65]

Thanks KansasKen. I'll do that.
Ed_Gee and Fishbreath: I have a rubber roof, so VHB tape is a no go for me.