Fiberglass tops and solar panels

vagari · May 30, 2013

I've recently looked at a couple of high top cargo vans. The fiberglass tops are very thin and flexible when i push on them. They will not support any weight. I'd be afraid to even put the flexible solar panels on the top. Do some cargo vans have more rigid/stronger fiberglass tops? Do conversion vans have better tops in which to mount solar panels? I don't need city stealth and would like to get the most solar up top as possible. Ideally I'd like to mount two 140 watt panels on a van.

stude53 · May 30, 2013

I've looked at the same thing, and have decided if I go the fiberglass high top route, That some reinforcement ribs on the inside would lend strength and facilitate attaching solar panels. Some work to be sure, but standup height is a priority with me. Bob

highdesertranger · May 30, 2013

yes some reinforcement would do the trick.  I don't now about the high tops today but back when I did van conversion there were cheap high tops and good high tops that you could walk on.  highdesertranger

Ziggy Moon · May 30, 2013

I weigh 195 pounds (I'm petite <img src="/images/boards/smilies/biggrin.gif" class="emoticon bbc_img">) and I can crawl upon my 1993 conversion van high top (to wash) without any problems with flexing. It's built like a rock actually. It's got me wondering, are the high tops on vans today generally thinner than they use to be..... or is there a difference with the high tops on cargo vans verses conversion vans?

Willy · May 31, 2013

 Some fibreglass tops are also double-walled w. insulation in between. I've had a few of these and, besides being heavier, they're somewhat stronger. ..Willy.

wrcsixeight · May 31, 2013

My conversion van fiberglass roof is fairly strong, but I'm not walking round up there without plywood under my feet.  One trip to Baja, I carried 2 2x8x1/2" sheets up there, and would put my camp chair up there for my morning coffee. On the flat upper surface the outermost fiberglass is almost 1/4 inch thick wither fiberglass matt, or the mold was sprayed with a chop gun, which is similar in strength to fiberglass matt. Then there is 1/4" to 3/8" of foam.  This foam is not dense.  The bubbles are large. In the back to the crown of the roof there are three 5 inch wide half inch thick strips of OSB glassed in and a 3 inch wide strip on the edge of the roof.  This is nice because it takes screws nicely from below.  These are glassed over with ~ 1/8 thickness of more fiberglass matt. Here is a photo of in between these sandwiched OSB runners where my solar wires entered the roof.  I have real cord grips here now, this photo was when I was adding the unisolar and upgrading the wiring for both panels.

The white foam is white foamboard insulation I added. From the crown forward it is just 1/4 inch thick fiberglass matt/chop, re enforced in areas with fiberglass cloth tape.  The shape of the roof up front gives it structural rigidity, whereas the longer flat areas in the back need the OSB and the "I" Beam effect that occurs when it is glassed over . The sides are 1/4 inch fiberglass. It weighs about 220 lbs with nothing attached to the ceiling, or roof. I have a 130 watt framed panel up there, and a 68 watt Unisolar adhesive panel next to it. This was before I added the 68 watt, or finished painting the corner feet.

Here is a whole lot of Plywood resting on some additional load spreading "feet", on top of the solar panels.

I have seen some taller turtle top type roofs which were just fiberglass with no wooden support.  I have no idea of the thickness or weight or strength. I think the roofs sold to the aftermarket do not need to be as strong as a van converted and put on a dealer lot, but this is a guess.

blars · May 31, 2013

You could go with a ladder-rack stlye installation with the weight supported by the sides of the van.

vagari · May 31, 2013

Never thought about a ladder rack. It could mount on the drip rail and would need to be tall enough to go over the high top.

David · May 31, 2013

If you don't mind getting messy, you could always fiberglass some plywood to the inside of the shell.  This would allow you to anchor into the wood for the mounting and long as the wood sections supported a large section of the roof it would be strong enough. My Falcon had a full aluminium frame on the inside which I anchored mine into.

DollarJoe67 · Jun 1, 2013

I can crawl around on top of this just fine.  After pulling off the ceiling panel, it seems the hi-top is thicker in some places than others deliberately for the purpose of retrofitting.  Some supports are screwed straight into the roof without poking through.  I can't imagine many roofs would have problems with securing solar panels.