How did you guys mount your solar panels to your roof?

[rang-a-stang]

I have the Cross Flex TPO roof. I mounted my solar panel using the Renegy Z Brackets and used 1/4" galvanized lag bolts to bolt them to my roof. I then covered that with Dicor to seal it and make sure the bolts do not back out.

BUT, I feel like the bolts don't have much "bite" and could pull out at highway speeds. The material under the membrane just feels like 3/16 or 1/4 inch ply wood.

Is there a more secure hardware to hold this down? I am not looking to re-mount it on channels or tilting it. I just want them to be on my roof and not have to think about them again (other than cleaning them every once in a while). Will these 8 bolts be good enough to keep my panel from peeling up if I hit 80MPH on the freeway?

[rang-a-stang]

Anyone?

[MR.M]

guess you could use molly bolts or Oscar rivets / that will expand and grab hold on the back side of the roofing

[corn18]

I think your concern is warranted. We have a membrane roof over some sort of sub roof. When I installed my solar panels, I wanted to use VHB tape to attach the mounts, but that is a no go on membrane roofs. So I have to screw them down. I had the bathroom vent out from the inside for some reason and looked at the roof structure. Couldn't really tell what it was made of.

So now I think I am committed to attaching the solar panel mounts with stainless steel lag bolts into the cross members. How the heck do you find the cross members? Turns out, they reveal themselves on dewy mornings. Who woulda thunk?

I decided to go with a unistrut mounting method to minimize holes and maximize the ability to hit the cross members. Installed the first two unistrut channels using 1 1/2" SS lag screws. The dewy roof method turned out to be fairly accurate. I missed a cross member on one attempt. I could tell the screw didn't find any purchase but I wanted to see how much holding power it had. I would say it was about equivalent to putting a screw into drywall. That is, not much.

My next 3 installs, I used this stud finder recommended on here somewhere. Worked a treat and I never missed a cross member and didn't have to wait for a dewy morning.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1



If you made it to this point, you know what I am going to say. I do not think screwing into just the roof without hitting a cross member is sufficient to hold on solar panels for road going vehicles.

[Canadian Eh]

I fabricated my own mounting hardware from 3" aluminum "L" stock. I cut down one side of the "L" to 2" and that was the base. I made them 6" long and used 3 per side of each panel. I wanted to spread all the forces of wind resistance and vibration over a greater area. I mounted the brackets to the panels, drilled the holes, lifted the panels up and put sealant where the brackets sit. I used a couple of screws with the head cut off and a slot cut in for a straight screw driver as guide pins. I set the panels back in place using the guide pins and screwed the panels down then ran Dicor over the brackets.

[itat]

Although I realize many folks don’t document their progress on a project, I have to say for this topic the responses would be better if they had pictures.

[Canadian Eh]

I should have taken pics when I put them up but between all the other things going on it took a back seat. The bus is parked in storage so I don't have the opportunity to take pics at this time.

[corn18]

Here's some pics of my install.

The first pic is the factory roof. You can actually see some of the cross members in the image. When it is dewy, they really stand out. I have a lot of good space for panels.

Second pic is the two sets of 10 ga wire I ran for the panels. I ran them down the same hole as the black tank vent (not in the vent pipe). Super easy and it dropped the wires right into the basement which is where all my equipment is installed. I ran two sets of wires because I knew I was going to install more panels and wanted to just do the run once.

Third pic is the home made tilting mount I used for the first two panels. I don't think I will ever tilt them, but it makes the install 100x easier. For the next six panels, I just used tilt mounts that I bought on Amazon.

Fourth pic is the panel mounted on the unistrut. I put angle brackets on the front of each panel as extra support in case they decided to try to fly off while going down the road. Not sure if they are necessary, but they were easy to install.

Fifth pic is the first two panels installed.

Sixth pic is where I am now with six panels.

[eric1514]

I used well nuts. They are self sealing although I did use lap sealant on top of them.

My roof is fiberglass but over 1/8” plywood. The well nuts penetrate both surfaces and when they expand, they hold both layers together along with providing a large rubber washer on both sides of the roof.

[rang-a-stang]

Thanks everyone.

This morning I went up and gave the panel an upward tug. No way was it safely mounted. I removed my panel, screwed some wide top stainless screws in the holes and put a blob of lap sealant over them. We are heading out camping today so I will have to address this when I get home.

I did bring a stud finder up there and found my cross members. They are spaced in a way where I would have to either completely move the panel to another spot on the roof, or I am going to need some sort of bracket (or both). The cross members are about 18" apart, on center, and my panel bracket holes are currently 41" apart. So I could get 2 of the 4 brackets into a cross member but I would rather have all 4.

When I get home I will continue researching this and come up with a plan. I plan to add another panel in the next year or so, so this has to be done right and where the panel is now. I will also take a bunch of pictures when I get home.

[Guspech750]

Originally Posted by corn18

Here's some pics of my install.

The first pic is the factory roof. You can actually see some of the cross members in the image. When it is dewy, they really stand out. I have a lot of good space for panels.

Second pic is the two sets of 10 ga wire I ran for the panels. I ran them down the same hole as the black tank vent (not in the vent pipe). Super easy and it dropped the wires right into the basement which is where all my equipment is installed. I ran two sets of wires because I knew I was going to install more panels and wanted to just do the run once.

Third pic is the home made tilting mount I used for the first two panels. I don't think I will ever tilt them, but it makes the install 100x easier. For the next six panels, I just used tilt mounts that I bought on Amazon.

Fourth pic is the panel mounted on the unistrut. I put angle brackets on the front of each panel as extra support in case they decided to try to fly off while going down the road. Not sure if they are necessary, but they were easy to install.

Fifth pic is the first two panels installed.

Sixth pic is where I am now with six panels.

[corn18]

If I wanted, I could go all the way to 11! (actually, 12)

[nvs4602]

I think I'm going to use these to anchor mine. I've used the on handrail on our stairs and the have worked great.

I'm thinking of buying this from Lowe's. Any recommendations? https://www.lowes.com/pd/TOGGLER-Snapskru-25-Pack-1-1-4-in-x-1-4-in-Dia-Mini-Drywall-Anchor-Screws-Included/3183261

[eric1514]

Originally Posted by nvs4602

I think I'm going to use these to anchor mine. I've used the on handrail on our stairs and the have worked great.

I'm thinking of buying this from Lowe's. Any recommendations? https://www.lowes.com/pd/TOGGLER-Snapskru-25-Pack-1-1-4-in-x-1-4-in-Dia-Mini-Drywall-Anchor-Screws-Included/3183261

I’m sorry, man, that’s just nuts. They’re meant for drywall and specifically for hanging things on a wall. You would never use one to hang something from your ceiling. They would pull right out.

[RKiersey]

I cheated and used the factory Rhino Rack.

[chriscowles]

A picture of my solar panels is below. Rockwood trailers have a 3/8" plywood roof deck with no cross members except under the A/C. It is framed with 1" aluminum tubing around the periphery.

I used #10 stainless hex-head drilling screws for aluminum for the brackets attached on the outer edge and 10-32 rivet nuts for the brackets mounted directly on the plywood. In both cases I laid butyl tape under the bracket before screwing it down, then covered the whole bracket with self-leveling Dicor sealant.

I used standard Z-brackets to mount the panels. I know that it will be a pain if I have to move them but I don't plan to do that. I can remove them fairly easily but reattaching the panels to the brackets without detaching the brackets from the roof would be a challenge due to lack of clearance, and I don't want to break the seal if I don't have to.

I considered mounting the panels on Superstrut (or equivalent) channels to make maintenance easier. Doing that would have added space for air flow, allowed using a spacer between the roof and strut to prevent pooling, and I could space the attachments more closely for security. But I had already spent more than I planned and couldn't find aluminum struts locally (steel struts add a lot of weight) so I bagged that idea.

I've tested the attachments from time to time when on the roof and they seem firm. As further security, I laced a stainless steel cable through all four and secure the ends to roof. Should one come loose it will damage the roof but shouldn't pose a risk to someone on the road behind me.

[kingoffixin]

I have had great luck with these at home and work. I'm not sure they would work in the thin roof decking though.

https://www.lowes.com/pd/TOGGLER-10-...B&gclsrc=aw.ds

[chriscowles]

Originally Posted by chriscowles

A picture of my solar panels is below. ...

I fixed the broken picture.

[rang-a-stang]

I am jealous of all the real estate you guys have for Solar panels! My roof is miniscule compared to you guys! I have one 260W panel that is 65"x39" and that leaves just enough space for 1 more panel of the same size.

I watched a guy on youtube use strut channel (just like Corn18 mentioned). He mounted the strut channel to his roof, then the panels to the strut channel. I am going to copy him. I can't find the exact video I watched but when I search "Solar Panel RV strut mount" I see a ton of videos that show the same thing. This will allow me to bolt the strut channel to the cross members, then bolt the panels to the strut mount. Will be MUCH more secure. I wont get to this for another 2 weeks though (have to rebuild the trans in my jeep this weekend).

Pics to follow.

[chriscowles]

Originally Posted by rang-a-stang

I am jealous of all the real estate you guys have for Solar panels! My roof is miniscule compared to you guys! I have one 260W panel that is 65"x39" and that leaves just enough space for 1 more panel of the same size. ...

If you have cross members in the roof, struts would be a secure approach. Consider their weight. Someone here on FRF used aluminum struts but they cost more.

520W is a lot of solar panels. If you need more, consider a suitcase.