Leveling prior to applying TPO on roof?

[gwtrike]

I bought a homemade teardrop trailer. The fabricator used some kind of white vinyl covered foam board for the roof and front whereas the sides are covered plywood.

The roof is uneven with seams between each panel of foam board as well as "protruding" round bolt heads covered in silicone for the bolts that affix the foam boards to the roof structure.

I want a clean, smooth, mostly seamless roof/front and plan to research Quick Roof, TPO, and thin aluminum sheets (that I can get from a metal fab near where I live) over the roof/front. No matter which product I wind up using, I want to ensure the foam baord structure is even and smooth from front to back before applying the outer layer (AL, TPO, etc).

Besides ripping out the foam boards and startig over (which is an option), can I use some kind of lightweight compound to ensure a level surface on the foam board from front to back? If so, what would you suggest?
Thanks,
Greg

[48Rob]

Got a picture?

Sounds like you might be better off removing what is there and using a continuous sheet, or gluing two or more thin sheets to give you a seamless look.
But it’s all just guessing until we can see a picture or several pictures so we can see what you see.
Using something to "smooth out" someone elses errors is usually just as poor an idea as the one you're trying to cover...

Rob

[gwtrike]

I hope you can see this. It isn't as bad as all that I guess, but you cant see where the seams are on top and in the back.

[48Rob]

Ouch...

If you like the slobbered on silicone look, it isn't bad.
You might be able to use some sort of edge trim that has a channel to accept a thin sheet of something, and lay it over the existing roof.
You could also use standard wrap around edge trim and resheet the top with aluminum, or even the same Filon type material, but of course you'll need to remove the carriage bolts? And attach the roof to the spars with something that will sit level.

I'd be tempted to remove it all and put what I wanted on it.

Rob

[gwtrike]

Yeah, I meant it's not that unlevel, but that bridge-rivet-look kills me. Thanks for your ideas. I've got a metal shop near me and I also thought about weather-proofing some wood trim - the thinner stuff that is more easily moldable - and affix it to the side and middle in a height small enough just to provide a level mount for FRP. I figure i can do that for less than $50. If i don't like it or find out it won't work like i think, I'll look into the metal shop and a sheet of aluminum.

[gwtrike]

OK, here's the goods now that I have had a chance to properly inspect the trailer... the roof is white FRP with the pebble side up. The roof is 11' 4" long and 3' 6" wide. The unsightly seam is at the 8' mark. Bolts were used to secure the FRP and the underlying foam insulation boards to wood ribbing. The bolts were caulked over, leaving me the seam that fits the 2 pieces of FRP together and 15-20 caulked over bolts. So, I'm not going to put another piece of FRP over it and will be looking into an aluminum skin once I see what the support structure really looks like... or I might sand down the seam and the covered bolts and reaffix the FRP.

[gwtrike]

OK, here's the goods now that I have had a chance to properly inspect the trailer... the roof is white FRP with the pebble side up. The roof is 11' 4" long and 3' 6" wide. The unsightly seam is at the 8' mark. Bolts were used to secure the FRP and the underlying foam insulation boards to wood ribbing. The bolts were caulked over, leaving me the seam that fits the 2 pieces of FRP together and 15-20 caulked over bolts. So, I'm not going to put another piece of FRP over it and will be looking into an aluminum skin once I see what the support structure really looks like... or I might sand down the seam and the covered bolts and reaffix the FRP... or I could chop off the trailer at the seam and close it off to create a rear platform for luggage or whatever.