Backing plates needed inside van roof for reinforcing solar panel mounts????

[Directshort]

On my van the roof metal seems pretty thin so for a 200 watt panel do you think reinforcing backing plates are needed under the solar panel mounting brackets?

I will be using 3M tape under the mounts but being a newb considering adding a bolt through the 2 front mounts for added safety but it would seem at a minimum some thin plywood or other material glued inside would help the roof deforming. I dented it just with my elbow while cleaning up there.

A thin backer material would be preferable to preserve what little head clearance I have inside the van.

 

[Ampster]

The force most likely will be uplift so a fender washer with a bolt will be better than a sheet metal screw.

 

[Directshort]

Sorry I meant to say the backing plates that would go on the inside of the van under the brackets for support.
But I imagine in a worse case scenario where say you hit a tree limb, sign, low bridge lol that there should be a weak link that prevents the whole roof from being peeled off and the aluminum soalar panel frame would seem to be the first part to give.

 

[eXodus]

anything on the roof will be hot. So choose you material accordingly. Wood is drying up - so don't use it structurally. Your roof should have ribs somewhere - can you try to locate those and put the screws through those at the front.
Like Ampster said - your main force is uplift - the panel wants to go up at the front.

So drilling a hole and using a 2-4 screws for each mounts with a washer should help. Or add a flat piece of metal underneith -something like 1/8 thick - 1,5mm- 2mm.

 

[HRTKD]

I know there are a lot of mounting solutions that are "no drill" and use adhesives. I'm not a fan of that type of install. I see significant winds here in the Rocky Mountains and I would like to have 100% confidence that my solar panels aren't going to come loose while driving down the road.

As suggested by eXodus, find the ribs that hold the roof up. That would be my plan "A". Placing a backing plate would be an acceptable option to me, as long as the plate was sturdy and large enough.

If the ribs aren't in a convenient location and you don't have easy access to put in a backing plate, you can use Unistrut to create a base to mount the panels on.

 

[eXodus]

I know there are a lot of mounting solutions that are "no drill" and use adhesives. I'm not a fan of that type of install. I see significant winds here in the Rocky Mountains and I would like to have 100% confidence that my solar panels aren't going to come loose while driving down the road.

First thanks!
those adhesives are great. I had 2x 100w panels glued on my roof for 4 years with 3m VHB tape and after both died (buy cheap, buy twice) - I tried get them off. That was a 2 day undertaking to get the panels of the roof. Had to grind them of.

I'm in Florida, so everything I build is for 150mph wind

Now I screwed them down, just for the sake of getting them removed at some point.
After this experience I think differently - when you glue something and do it correctly, it's for eternity.

 

[HRTKD]

I'm sure the adhesives effectiveness depends on what you're putting it on. The EPDM roof on my trailer is 14 years old. It's not leaking or showing signs of failure, but it doesn't come clean at all when using a recommended cleaner. An adhesive on a fiberglass or metal roof would work pretty good. That said, I know Eternabond goes down on my roof and is very, very reluctant to come up.

 

[Directshort]

Did you try alcohol to remove the VHB tape? Supposedly if you soak it for a while it's a pretty good solvent for the tape.
Somebody else said you can "saw" the the taped item off by using a fine piece of piano wire like dental floss to cut through the bond.

 

[RCinFLA]

3M VHB tape is used to hold in the windows on the Dubai 2700' tall Burj Khalifa skyscraper, but that says nothing about your van's roof paint adherance.

 

[eXodus]

Did you try alcohol to remove the VHB tape? Supposedly if you soak it for a while it's a pretty good solvent for the tape.
Somebody else said you can "saw" the the taped item off by using a fine piece of piano wire like dental floss to cut through the bond.

after cutting the panels to pieces to get it of. I tried soaking the tape with various stuff - but it just smeared the glue all over.

Got the remains off with a wire brush in a drill, then I had to repaint the roof....

I've cut through the tape

3M VHB tape is used to hold in the windows on the Dubai 2700' tall Burj Khalifa skyscraper, but that says nothing about your van's roof paint adherance.

The freaking tape is strong. My cars trailers walls are attached with VHB tape. When something fails then it's usually the paint to metal bond, but the tape itself not.

 

[Zil]

I ran 2 uni-strut front to rear and mounted the panels to the uni-strut. The uni-strut is fastened to the roof with three 5/16 bolts each. I used rubber sealing washer and a large fender washer under the nu-loc nut on the inside of the van roof. I get some reverb noise on especially ruff drives or excess wind. But it is only noise. it has all been good for 3 plus years and thousands of miles.

 

[HaldorEE]

I know there are a lot of mounting solutions that are "no drill" and use adhesives. I'm not a fan of that type of install. I see significant winds here in the Rocky Mountains and I would like to have 100% confidence that my solar panels aren't going to come loose while driving down the road.

As suggested by eXodus, find the ribs that hold the roof up. That would be my plan "A". Placing a backing plate would be an acceptable option to me, as long as the plate was sturdy and large enough.

If the ribs aren't in a convenient location and you don't have easy access to put in a backing plate, you can use Unistrut to create a base to mount the panels on.

I am using rain drip mounted ladder racks on my E350. I know these are solid. I mistakenly drove into a low ceiling with these and they stopped the van without coming off. I don't see wind load being enough to take these off my van. Those ladder racks are really, really solid and so are the rain drip edges. Way stronger than I expected them to be. Had a bit of repair to do afterwards ?.

 

[HRTKD]

Sorry to see that damage to your vehicle, even if it was minimal. It looks like the building got the worst end of that impact.

Those look like a solid, non-invasive, mounting solution!

 

[HaldorEE]

Sorry to see that damage to your vehicle, even if it was minimal. It looks like the building got the worst end of that impact.

Those look like a solid, non-invasive, mounting solution!

Way stronger than I feared this might be.

I cut the excess height off the tops of each rail. Need to mount some curb finders so I don't scrape off the luggage carrier.

Something like this.

Amazon.com: SUPERIOR 26-6331 Duplex Twin Curb Feeler, Chrome, 10.5" Long : Automotive

Buy SUPERIOR 26-6331 Duplex Twin Curb Feeler, Chrome, 10.5" Long: Gauges - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

 

[Pnw_steve]

VHB is amazing stuff when used properly.

Don't find yourself in the same situation as the poor guy in CA last year who used (only) VHB tape to mount his panels on his RV..

One came loose at 60+ miles an hour and hit another car. One young lady died in the accident. The RV driver was charged with manslaughter.

 

[Directshort]

That was my worst nightmare having a panel fly off so I ended up using the vbh tape but also ran a 1/4" nut & bolt through each one and used 8" square wood backing plates glued to the inside roof since the mounts could not be near the ribs.

The 180W panel did great on the hiway at 85 mph driving and sometime with severe winds when crossing Wyoming and it never budged or fluttered.

I actually got caught in a storm and before I could pull off the hiway had encountered a 70 mph crosswind gust that snapped the upwind plexiglass window rain guard in half almost scared me to death but the panel stayed on.

The panel is long and with just the 4 mounts at the corners the panel would bounce and flex up and down something horrible and I was really bummed at first it was so bad but then I added a center support to each side and that really made it rock solid.

 

[GSXR1000]

rivnuts might be an option

 

[HaldorEE]

They can loosen up which is a royal pain in the rear. For sheet metal you really want to clamp the sheet metal between two metal surfaces that aren't going to yield. Flange nuts exist for a reason.