Mounting Solar Panel

[Sagardner290]

I have a new 2024 Freedom Traveler and want to mount a solar panel on the roof. What is the best way to mount the panel so it doesn’t go airborne while I’m driving. I was going to use butyl tape under the brackets then sealant around and on top. What type of hardware should I use to make sure it’s secure? Thanks for the help.

 

[Chateau_Nomad]

I have a TPO roof with three 200 watt Rich Solar panels. I used the following Z bracket kits... I marked and carefully drilled small pilot holes. Coated the bottom of the brackets with Dicor. Then drove the screws in to secure to the roof. Then covered the bracket "foot" with a generous patch of EternaBond tape.

Two cross-country trips in fours years... no issues.

Amazon.com

 

[Sagardner290]

I have a TPO roof with three 200 watt Rich Solar panels. I used the following Z bracket kits... I marked and carefully drilled small pilot holes. Coated the bottom of the brackets with Dicor. Then drove the screws in to secure to the roof. Then covered the bracket "foot" with a generous patch of EternaBond tape.

Two cross-country trips in fours years... no issues.

Amazon.com

Those were the brackets I ordered. Did you look for any studs or structural supports to anchor to?

 

[Chateau_Nomad]

Those were the brackets I ordered. Did you look for any studs or structural supports to anchor to?

Nope. There's a layer of plywood under the TPO. I forget the thickness offhand, but I figure if it's thick enough to support a "walk on roof" between structural supports, it's thick enough to provide "bite" for those screws.

As I drove in each screw I pulled up on the corner of the panel fairly hard to check integrity of the screw-into-wood hold strength. All threaded very well. I'm also very confident of each contact point/screw mount being absolutely water tight.

I just did a hands-and-knees roof washing today and carefully checked the integrity/adhesion of all EternaBond tape on the roof. It looks as good as the day I applied it. If I were to do this today, the only thing I'd change is use Geocel ProFlex under the bracket feet instead of Dicor. However, with the Dicor completely covered/sealed I doubt there's any critical difference.

 

[Sagardner290]

Sounds good, that is my project today. Thanks for all the input and help.

 

[rman-THOR]

Nope. There's a layer of plywood under the TPO. I forget the thickness offhand, but I figure if it's thick enough to support a "walk on roof" between structural supports, it's thick enough to provide "bite" for those screws.

As I drove in each screw I pulled up on the corner of the panel fairly hard to check integrity of the screw-into-wood hold strength. All threaded very well. I'm also very confident of each contact point/screw mount being absolutely water tight.

I just did a hands-and-knees roof washing today and carefully checked the integrity/adhesion of all EternaBond tape on the roof. It looks as good as the day I applied it. If I were to do this today, the only thing I'd change is use Geocel ProFlex under the bracket feet instead of Dicor. However, with the Dicor completely covered/sealed I doubt there's any critical difference.

Sorry that's not a very good analogy, it's about 8th inch thick and the rigidfoam underneath with the second layer of this thin plywood for your ceiling is why you can walk on the roof. It was never designed or meant to hold screws.

 

[Mark54]

Sorry that's not a very good analogy, it's about 8th inch thick and the rigidfoam underneath with the second layer of this thin plywood for your ceiling is why you can walk on the roof. It was never designed or meant to hold screws.

If that's the case, flex panels would be what I would use, with VHB tape underneath, and eternabond tape on all edges. Tape wiresets down too, and use a gland to send wires inside.

 

[Chateau_Nomad]

Sorry that's not a very good analogy, it's about 8th inch thick and the rigidfoam underneath with the second layer of this thin plywood for your ceiling is why you can walk on the roof. It was never designed or meant to hold screws.

I have pics somewhere showing the sandwich when I installed my Maxx fans. Thor must disagree with you also... have you noticed how many screws Thor drives into that thin plywood to secure those roof vents?

Sorry... I disagree with your opinion. PROPERLY installed there's literally thousands of TPO/plywood/Styrofoam/plywood sandwich roofs with successful solar panel installs. Some 5ers and larger motorhomes have the entire TPO roof covered... often 10 panels. I've heard more about shoddy bracket installs on metal roof racks allowing "flying panels" than those properly mounted on TPO roofs... there's actually recalls by manufacturers.

Point is... just driving the screws into the 1/8" plywood is not enough. The sealant and tape spread and lifting forces.

About flex panels. Do your research. Consider how a panel is constructed. The conductors between cells are micro thin strips. Many reports of failure from flex causing cell failure. Then there's the heat issue. A rigid panel has airspace below for cooling. However, many people have indeed used flex panels and are happy. Just consider the potential downside.

 

[JimC-THOR]

Use a stud finder and locate the roof support framing. For Thor items it is aluminum. I don't know about other manufacturers. Thor has exploded diagrams of their frame layout that are available.
I screwed C-channel rails onto the roof frame rails with #12 self drilling sheet metal screws, and applied DICOR self leveling caulk. Then I used inverted carriage [ or brass toilet mount bolts] through the Z-brackets [shown in an earlier post] to mount my solar panels. In four years, I have had zero issues.
JC

 

[Mark54]

I have pics somewhere showing the sandwich when I installed my Maxx fans. Thor must disagree with you also... have you noticed how many screws Thor drives into that thin plywood to secure those roof vents?

Sorry... I disagree with your opinion. PROPERLY installed there's literally thousands of TPO/plywood/Styrofoam/plywood sandwich roofs with successful solar panel installs. Some 5ers and larger motorhomes have the entire TPO roof covered... often 10 panels. I've heard more about shoddy bracket installs on metal roof racks allowing "flying panels" than those properly mounted on TPO roofs... there's actually recalls by manufacturers.

Point is... just driving the screws into the 1/8" plywood is not enough. The sealant and tape spread and lifting forces.

About flex panels. Do your research. Consider how a panel is constructed. The conductors between cells are micro thin strips. Many reports of failure from flex causing cell failure. Then there's the heat issue. A rigid panel has airspace below for cooling. However, many people have indeed used flex panels and are happy. Just consider the potential downside.

True about flex panels not being as efficient- subject to higher heat inidices, etc.
Though I never had any cell failure in my Renogy panels on my Rialta.
My Tellaro has framed panels and they are much cooler with an air space below.
If you use enough screws and butyl tape, Dicor or any other waterprooofing, C-channels are the way to go for sure. Then use nyloc nuts ont eh panel brackets. Thor was known for not using locking hardware and panels have flown off in transit!

 

[Sagardner290]

I consulted the roof schematics and there are reinforced areas on the roof that Thor recommends you to mount aftermarket items.

 

[Chateau_Nomad]

I consulted the roof schematics and there are reinforced areas on the roof that Thor recommends you to mount aftermarket items.

Sounds like a "do as I say" and not "do as I do". If you feel more confident mounting to those "reinforced areas", go for it. Nothing like heart burn worrying about your solar panels flying off!