Teardrops n Tiny Travel Trailers

Hi All,
How thick is the plywood on the walls and floor of an original Kit teardrop?
I'm plannin' my first build and want to keep it real simple.
Thanks,Smokey

1/2". The biggest problem with 1/2" is the edge trim, which was attached with aluminum spiral nails, and the nails must penetrate the plywood Exactly in the center to avoid breaking out the ply's, even then it still may "bulge" the side walls a little, definately visible once the aluminum is on. And, the doors tend to warp easily with 1/2" ply. But that is what they used.

wonder if that could be avoided by pre-drilling the holes with a bit slightly smaller than the nail. Maybe hit 'em with a dab of wood glue to hold them in.

Would take a while but would probably help protect it from splitting or bulging?