All set to attach the 1st of 2 solar panels. Aluminum roof. Very sturdy. At a vent opening, looked like about 1 1/2 inch plywood. Put a lag screw in and it spun and spun and spun, etc. No grab.Knocked all around the roof and didn't find much in the way of studs except along the outer edge. I really want these on the roof.ANY IDEAS?????I'm thinking--Screw 2 brackets in the outer edge studs. On the other side of the panels----drill through the roof and bolt them in from inside. There wont be any headroom issues.Is this sane? Is it doable?

I wouldbe surprised to find much more than 3/8 plywood. You should, however, be able to use a studfinder to locate the rafters to secure the panels.

Molly bolts will grip but .. I do not know how much wood you have.. Half to 3/4 inch is common if you can walk without bouncing. A stud finder or metal detector MIGHT help you.. Do not know.

I just measured the thickness of the wood underneath the aluminum roof at a vent opening--It's 1 1/2 inches thick. This is near where I drilled the holes that didn't take. I used 1 1/2 inch lag screws which would have stopped short of coming through.Very confusing.

The vent where you measured the thickness is just the framing for the vent. It probably just extends out 1 1/2" also.

full timer--Sounds logical. However, the roof and ceiling are the same level throughout the rv. Maybe insulation in between a wood sandwich for the roof outside and the roof inside?Pretty sure I'm going to attach the one side through the roof, bolting on the inside. A couple more holes in the roof should not be problematic when sealed.IF THIS IS INSANE, PLEASE LET ME KNOW.

SOLAR ATTACHMENT SURPRISE--NEED SUGGESTIONS | Good Sam Community

18 Replies

TOMMY47
Explorer
May 26, 2014
WANDERING--great idea. I see these at garage sales all the time.
HOWEVER, I installed them today.
Attached one set of brackets to the channel on each side and the other brackets through the roof. Seems real secure.
wanderingbob
Explorer II
May 25, 2014
A tip for dumpster divers and yard sale enthusiast , Several years ago I found an aluminum extension or shifting ladder in a dumpster . I fastened it to the roof of my trailer and had a twelve foot roof rack with only 6 or 8 fastening holes . I carried kayaks , lumber ,spare tires et al . Worked great ! Since them I capture every aluminum ladder that I can ! I had one trailer that I hinged a ladder opposite of my factory ladder and tied a kayak to each . In my toy hauler I fastened a ladder to the ceiling in the cargo area to hang tools , line , fishing tackle but my mean ole wife used it as a hanging closet for clothes . I believe a ladder would make a good place to put solar panels .
Shadow_Catcher
Explorer
May 25, 2014
I attached our 185W panel with 3M VHB tape. Surface prep and enough contact area are critical. Advantage no holes.
RoyB
Explorer II
May 25, 2014
One other item of interest - recently a post was on here where the OP had replaced his roof on his trailer and in the process of screwing everything down he apparently screwed into some 12VDC ceiling lights wiring creating a dead short (Blows fuses when turned on).

No easy way to repair the problem without removing the roof again so I think he has finally decided to abandon the current DC wiring for the ceiling lights and re-install new wiring to the affected ceiling lights the best way he can.

Really need to watch out for something like this as well... More surprises you may NOT want to have...

Roy Ken
RoyB
Explorer II
May 25, 2014
I am going to do much like TECHWRITER reported. Use the edge of the roof where I can see metal supports and attach aluminum UNISTRUT type mounts across the trailer roof. It is also not out of the question of using the sides of the roof for mounting frames to attack my unistrut sections going across the roof. I can do this with ease on the back side of the trailer roof but the front side has the awning attached which may cause some problems. Then I can slide the solar panels across any portion of the roof where the two unistrut rail mounts are located. The unistrut also will raise the panels up off the roof as well.

In my OFF-ROAD POPUP case I will also have a weight problem with my roof electric raise motor with all the extra weight being added by the panels.

The quick mounts using the unistrut will allow me to mount a couple of my panels with ease to the roof after I have raised it. I will make these specific panels my so called portable one where i can move to the ground and keep in the high sun as required during the day if needed.

I am thinking of two 140WATT Panels on the front portion of the roof and one larger 240WATT PANEL across the rear portion of the roof. This will give me around 480WATTS of solar panels to use. Hopefully my solar controllers will give me 14.4VDC at around 20AMPS of DC Current to help charge my 300AH Battery setup during the high sun days. My primary charging method will remain being my 2KW Generator providing power to the 30AMP Shore Power Cable using a RV30A-15A adapter which will use my on-board smart mode converter/charger to re-charge my batteries in as quick of a generator run time as possible... This works no matter what the weather elements are.

Just some of my solar panel install thinking here...

Roy Ken
Padlin
Explorer
May 25, 2014
While I haven't done it yet, I'm planning on using lengths of square aluminum tubing attached to the roof with either epoxy or VHB tape, then attaching the Z brackets to the tubing.
SCVJeff
Explorer
May 25, 2014
Well it doesn't sound like you're having much luck with screws.... Do a little research on VHB and you might change your mind. I did...
TOMMY47
Explorer
May 25, 2014
I don't trust glue in a situation like this. I'm old fashioned, I guess.
westend
Explorer
May 25, 2014
The roof vent has a box built around it, between the ceiling rafters. If you start at the front vent, at the rear edge of the vent box, measure back 16" and put an "X" rear of that line. Using either a stud finder or small drill verify that a ceiling rafter is beneath your "X". Most RV mfg.'s try to place rafters on 16" or 24" centers as the paneling and aluminum sheet is dedicated to a 4' dimension.
SCVJeff
Explorer
May 25, 2014
If it's an aluminum roof, why not just attach them with Scotch VHB? There are lots of folks that mount panels on fiberglass roofs like this with no holes and they don't move. I have 500w attached with VHB