Bolting solar panels to rails through roof?

[Touring4]

Originally Posted by Drew Bru

We used BlindBolts into the ribs, but if we'd removed the ceiling I'd have bolted all the way through and used carriage bolts with nylon locknuts. The Blindbolts have held up fine though, no sign of them coming loose in 2 years of use. I don't think I'd trust self tappers...they might be fine but the Blindbolts weren't outrageously expensive and were pretty simple to install.

Has anyone tried using an adhesive? I was thinking about using one of the loctite adhesives and doing aluminum unistrut down the full length of the bus. I had seeing water dripping from bolts

[HamSkoolie]

Originally Posted by Touring4

Has anyone tried using an adhesive? I was thinking about using one of the loctite adhesives and doing aluminum unistrut down the full length of the bus. I had seeing water dripping from bolts

I would never trust an adhesive to attach such a large aerodynamic item that is capable of death and destruction should it come loose. Remember, you're probably just gluing to paint that may or may not stay attached.
It's actually a good idea (I'd recommend it) to use a steel cable through the frame of any panels and then secured to solid structure just in case a panel ever comes off. It happens, particularly with panels mounted with just Z brackets and self tapping screws like so many DIY'ers do. Those puppies will go right through a windshield and kill someone.

[powderskier]

Hi I have my entire 40 ft of usable roof covered in panels all tek screwed into the hat channels. I use 14 ga. angle, tek screwed every 3 in. Into the panel and channel. Every hole I put in a squirt of silicone and a bead the length of the angle, then silicon over top of the screws as a kind of lock.
This system has been in service for over 6 years and driven from Northern Saskatchewan to Southern Mexico and back several times. I've had my awning almost leave the bus and had a emergency vent leave the bus in a windstorm in New Mexico, but never had any issues with the panels. This way there is no entry through the roof.

[BriteLeaf]

Originally Posted by Byron

Hi all,

Just wondering, do folks use self tapping screws, or drill through roof support beams and lock them into place with nuts on the interior side of the roof?

From my personal experience, I have my panels bolted completely through the roof.
They’ve been that way with no leaks because I was VERY DILIGENT about sealing each of the sixteen by one quarter inch holes that I drilled into my roof more than three years ago.
If I knew then what I know now I would have put them on the driver’s side of the bus.
More sunlight throughout the day.

[HamSkoolie]

Originally Posted by powderskier

Hi I have my entire 40 ft of usable roof covered in panels all tek screwed into the hat channels. I use 14 ga. angle, tek screwed every 3 in. Into the panel and channel. Every hole I put in a squirt of silicone and a bead the length of the angle, then silicon over top of the screws as a kind of lock.
This system has been in service for over 6 years and driven from Northern Saskatchewan to Southern Mexico and back several times. I've had my awning almost leave the bus and had a emergency vent leave the bus in a windstorm in New Mexico, but never had any issues with the panels. This way there is no entry through the roof.

I'm trying to picture how that works.
Are the 14ga angles tek screwed to the roof and then the panel frames tek screwed to the angle? If so that means your panels are tilted in opposite directions due to the curvature of the roof?

[powderskier]

Hi. No the angle is maybe 3 inch x 1.5 in. So the panels are slightly above the curve. And yes Tek screws into panels and bus rib all silicon covered so basically they are unable to come loose. I believe I used #10 Tek screws they hold about 80 to 90 lbs each so over the entire panel I believe it is more than safe.

[CritiqueThisBus]

Originally Posted by Byron

Hi all,

Just wondering, do folks use self tapping screws, or drill through roof support beams and lock them into place with nuts on the interior side of the roof?

I plan on going the Flexible Solar Panel route and just glue/seal them down to the roof and hook them up in parallel. Less weight and if one were to get torn off the roof it's a good chance it won't kill anyone on the way down.

Downside is in the AZ sun the panel may cook to death on the roof due to lack of ventilation under it but you have to weigh the good with the bad for each option and make a choice. I'm going with less holes in my roof and less possible carnage to others if my installation of rails and solid panels fails.

[Salty Walty]

Pictures show what I did. Some of the hardware came from McMaster-Carr, specifically the threaded square strut washers and the Nord-Lock washers. I haven’t driven it yet, but the entire setup is uncovered and has withstood heavy storms and strong winds without budging or leaking. I put butyl tape in the drilled holes as well.

From memory, the bolts were 1/8. I think I did 8 on each piece of 10ft strut. The strut was spaced apart per the rib access (as pictured). The underside of each bolt had teeth to grab the washer. Going from the inside to outside of the bus it was:
1) Bolt head
2) Washer (1/4”?)
3) Nytrile (I think) washer
4) Roof
5)Butyl tape in hole
6) Nytrile washer
7) Washer
Strut
9) Threaded square washer
10) Nord-Lock washer
11) Lock nut

The benefit of the nitrile and regular washer on the top of the roof, but under the strut, is that they help seal the hole while also elevating the strut off the roof so that water doesn’t pool between the struts. Despite the struts being very slightly angled away from center, I didn’t have an issue with attaching the perpendicular struts. I’ve yanked and pulled on the struts and panels. No budging.

[Drew Bru]

Originally Posted by Drew Bru

We used BlindBolts into the ribs, but if we'd removed the ceiling I'd have bolted all the way through and used carriage bolts with nylon locknuts. The Blindbolts have held up fine though, no sign of them coming loose in 2 years of use. I don't think I'd trust self tappers...they might be fine but the Blindbolts weren't outrageously expensive and were pretty simple to install.

Because someone PMed me and asked, here's a picture of the bracket on the outside. We Blind-Bolted the brackets between the rows of rivets, but I'm not actually sure how many layers of sheet metal it goes into.
There's a LOT of grime up there so its hard to tell what's going on. Every bolt and rivet has been smeared with lap sealant as has the seam where the roof panels overlap.

[Oldyeller]

I bought the heavier gauge superstruts and ran them the length of the roof right above the longitudinal ribs. Doing it that way allows me to put bolts through 4 thicknesses of sheet metal on both sides (front and rear) of each rib. I originally wanted to use 3/8" bolts but discovered that the flanges of the ribs weren't wide enough so I went with 5/16" bolts with washers and nyloc nuts. If I counted correctly I have 48 bolts in total, 24 in each strut.

My solar panels are 80x40" so I'm going to run them length across the bus. That's on the list for this summer. I won't make final decisions about how I'm going to do that until I get a panel on the roof and see what it looks like though I have an idea of what I'm going to do. Of all the things I have to do to build this bus the solar has me the most nervous. So many ways to screw it up with huge negative ramifications.

[Magnum]

Thanks for the picture. Is very helpful.

[Magnum]

Originally Posted by Drew Bru

We used BlindBolts into the ribs, but if we'd removed the ceiling I'd have bolted all the way through and used carriage bolts with nylon locknuts. The Blindbolts have held up fine though, no sign of them coming loose in 2 years of use. I don't think I'd trust self tappers...they might be fine but the Blindbolts weren't outrageously expensive and were pretty simple to install.

Thanks for posting about these bolts. Expensive but will make the system much safer.

[Peterjk]

Im a little late to the party but Im real happy w my set up. I just Lag bolted 2/6 boards running front to back of the bus with steel L brackets.
Panels sit on the 2/6 boards, hinged with garage door hinges on one side to allow for tilt up during winter time. Total of 4 60 cell panels. Back of the roof is the deck using 2 by 12 boards.

The whole set up is so solid I could probably build a room addition on the roof.
Total materials were minimal, lag bolts which just drilled and screwed thru the roof ribs w steel washers. Sealed of course. L brackets and the exterior grade 2/6 boards, 4 in total.
Picture is here. Cheers

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