Firetodd
New Member
If anyone think lags bolt into rafters is less ideal than well nuts or plus nuts, let me know….
Solar panel mounting on RV
- Thread starter Firetodd
- Start date
You won't hear me complain.
Whinny
Solar Enthusiast
- Joined
- Dec 24, 2020
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- 399
You may wish to look into the ceiling area to see if you even have rafters. Some manufacturers use aluminium trusses, some wood truss and some just a plywood/styrofoam sandwich. See if you can take out a speaker and take a look.......if you have ceiling speakers. If you put a fat lag into some of the assemblies it may just split.
One poster here contacted his manufacturer and they sent him a layout of the roof of his trailer.
One poster here contacted his manufacturer and they sent him a layout of the roof of his trailer.
I pulled out the inside cover on my exhaust fan to see what the "attic" looks like. That worked out great.
Firetodd
New Member
Firetodd
New Member
That scares me to think that I could split the assembly.
Zwy
Solar Wizard
Predrill the holes using a 5/32nd bit for 1/4 inch holes. Be sure to use a bit depth stop or piece of tape so you don't drill too deep or you will find your ceiling is ventilated.
Firetodd
New Member
I did email Forest River and asked about the roof construction and possibly getting a layout of schematic of the roof. This was their response: “The roof would be made of rafters and decking. Unfortunately we do not have any schematics available to us. I know this isn't much help, and I apologize for that. Have a great day, and as always thank you for being a valued forest river customer.”
Your roof has a lot more arch than mine does. My ceiling is way flatter than than yours. Isn't yours advertised as having a "cathedral ceiling"?
Whinny
Solar Enthusiast
- Joined
- Dec 24, 2020
- Messages
- 399
With that much arch keeping the 2 unistrut's parallel may be difficult with those brackets. Consider using 2 pieces of 2 inch aluminium angle about 4" long boled in a "U" shape mounted at right angles to the unistrut to allow for adjustment. That would also give you more space for multiple screws per foot as well.
If you can:
1) Find the rafters accurately
2) Know the material type used to determine if they are suitable for a 1/4" lag screw into them without splitting (if 1*1 which is typical even a pilot hole is not likely to prevent splitting for 1/4" lags)
3) Know that the roof membrane, deck, and rafters are properly sandwiched together without gaps between that you will distort clamping down. Don't assume this is the case as with that amount of roof arch it likely will be vertical risers off a horizontal rafter to the deck to set arch.
Then go for it.
If not then the j-nuts (deep rivnuts) through the membrane and the deck and expanded behind the deck is the best bet. The failure mode to be worried about is leaking and the deck (if wood) rotting and no longer a mechanical grip for the j-nuts. But proper sealing and yearly inspection takes care of this issue.
Firetodd
New Member
Today was a good day!
I had ordered 50 of the rubber well nuts and only 25 of the plus nuts. Once I decided to use the plus nuts, I realized I only had room for one mistake…. I drove to my fire department’s maintenance shop and borrowed a tool to properly set the plus nuts and brought my spare plus nut. I had them show me how to use the tool and we used the spare. Yikes!
I had ordered 50 of the rubber well nuts and only 25 of the plus nuts. Once I decided to use the plus nuts, I realized I only had room for one mistake…. I drove to my fire department’s maintenance shop and borrowed a tool to properly set the plus nuts and brought my spare plus nut. I had them show me how to use the tool and we used the spare. Yikes!
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Firetodd
New Member
I went up on the roof and used a stud finder and realized I could see the location of the rafters as well! I marked the location a with tape.
I brought 4 of the 10 foot sticks of unistrut up the ladder and put them on the roof and then put together 12 mounting assemblies and a bag of tools. I then realized I had to build a mock up on the ground to ensure I had the proper dimensions to ensure I drilled the holes in the right spots. I measured the holes in the panels and they were 42.75 inches apart and the unistrut inside edges were 41” apart.
I brought 4 of the 10 foot sticks of unistrut up the ladder and put them on the roof and then put together 12 mounting assemblies and a bag of tools. I then realized I had to build a mock up on the ground to ensure I had the proper dimensions to ensure I drilled the holes in the right spots. I measured the holes in the panels and they were 42.75 inches apart and the unistrut inside edges were 41” apart.
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Firetodd
New Member
I then built the supports under the struts and measured them three times and marked the hole locations with a sharpie. Now was the moment of truth! I drilled the holes and it went well. I put the plus nuts in and they secured perfectly! I will be leaving the factory mounted 50 watt panel as it fits under my panels….
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Firetodd
New Member
Firetodd
New Member
Now I’m sitting at my son’s baseball game. Tonight after dinner, I will trim the butyl and cover each mount with dicor lap leveling sealant!
Due to the curved roof, the parallel struts are now angled away from each other. I am curious how you plan to mount the panels to compensate for that.
Also, I don't really understand why/how you are using the plus nuts when you were able to locate the rafters. You didn't use the plus nuts when attaching to the rafters, did you?
Also, I don't really understand why/how you are using the plus nuts when you were able to locate the rafters. You didn't use the plus nuts when attaching to the rafters, did you?
Firetodd
New Member
The aluminum rafters beam below the plywood decker is hollow. The plus nuts entered and locked into the open area.
I had wondered about the angle of the unistrut as well! I’ll adjust the angles by placing these angled washers in between the mounts and the unistrut:
I had wondered about the angle of the unistrut as well! I’ll adjust the angles by placing these angled washers in between the mounts and the unistrut:
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Firetodd
New Member
The aluminum rafters beam below the plywood decker is hollow. The plus nuts entered and locked into the open area.
I had wondered about the angle of the unistrut as well! I’ll adjust the angles by placing these angled washers in between the mounts and the unistrut:
I had wondered about the angle of the unistrut as well! I’ll adjust the angles by placing these angled washers in between the mounts and the unistrut:
