Best way to fasten Solar to RV Roof for Solar Newbie?

I'm interested in dipping my toe into the solar arena, and was going to use a 45w kit I bought back in 2000 (still new-in-box) on the roof of my 24RL.

It's 3 separate 15w panels that have two small (#10 screw size) mounting holes on each end of each panel.

I hate making holes in my EPDM roof covering, but I see no other good way to do it.

I don't think just screwing the panels directly to the roof w/ the supplied #10 wood screws would be the way to go, as I'm not sure whether having almost zero clearance in the area between the roof and the panels wouldn't build moisture or something, so was thinking of bending some aluminum into "Z" shaped rails about 1" long w/ 1/2" legs so that the small brackets are mounted to the panels with a single #10 machine screw, then the brackets are screwed to the roof of my RV with two #10 sheet metal screws, so they cannot rotate, and well-sealed with Dicor lap sealant. This would be on the down-sloping rear area at the back of the coach.

This would have the advantage of getting the panels up one inch off the roof (cooling circulation), and allow water flowing down the roof to continue relatively unimpeded around the brackets.

I'd ideally like the brackets to be more than 1" long, but the wider they are, the more debris and water they'd catch and collect (since they'd be mounted across the coach). In addition, since the roof is curved side-to-side, a long straight bracket rail could not be used.

I figure to run the wires down the fridge chase to the supplied charge controller (at 45 watts it's small-about 2" X 3" X 1" thick), and connect the output to the 12v connection at the base of the fridge behind the ventilation panel. Since 45 watts won't make more than 4 amps charge current, I figured I don't need any heavy or fancy wiring directly to the batteries. Do I need a blocking diode in addition to the charge controller, or does it have one inside already (the directions don't say, or reference an additional diode).

I know fixing the panels to the roof will mean that I am never optimally oriented, either azimuth or elevation, so shouldn't expect more than 1 or 2 amps under a lot of circumstances, but it will at least keep an already charged batter bank (2) topped off.

Anything I mentioned above sound bogus, or like a bad idea?

Any ideas how to improve the installation either electrically, or mechanically?

My main consideration is to not damage my roof, with the secondary consideration actually making electricity.

How about hail damage to the panels? I live in TX, and though we seldom get hail, it DOES happen, so I was wondering how resistant to damage they are. I DO have access to all the polycarbonate or acrylic plexiglas I want. It has 92% transmittance, and one thought was to simply put 1/8" plexi over the panels for impact resistance. Bad idea?

Thanks,
Bob

Are those the Harbor Freight panels?? I think Portagie has some, but uses the ground mount. Personally, I would only have a pro-solar RV installer do it...but know it does cost $$.. Solar panels also require a space underneath them for cooling effect, so a standoff mount is required. Good Luck, and I am looking at them when I got to Quartzite in Jan for the big RV show. Plenty of dealers there to get advice from.

It's really easy to install.

Pick a location close to the refrigerator vent on the roof.

Get the panels with the mounts which also elevate them a few inches off the roof. Locate the brackets over to the roof trusses as much as you can so the screws bite in more than the 3/8" plywood. You can use the 14x14 vents for reference point. The trusses run on 16" centers. Seal screw heads/brackets with roof patch. Attach the wiring to the panels. Run the wires down the refr chase so you don't have to drill chase the wires through the roof/ceiling cavity. If you have a charger controller with a fancy digital display, mount it where you can see it. I mounted mine close to the converter so I could use the heavy gauge 12V lines (6 ga?) that run straight to the battery box. Done.

Photos of my install.

I ran my wires down the inside of the wall in the hallway/bathroom. I had a tank vent going up the same wall space and drilling a hole big enough for your wires through the collar of the vent and next to the pipe puts you inside the wall. For me I was able to drill a hole from the rear of the storage space to run the wires right into the storage. From there is a short jaunt to the front of the rig for a battery hitch.
Solar Panel Installation Photo
Front Solar Charger/Inverter/battery Installation Photo