No, It is just 3/8 acx plywood, it's really about .320 thick. The roof seams and edge seams were done with fiberglass. I did seal/cover it with marine epoxy resin, 2 coats, it seems to penetrate the wood and seal it good. Then 2 coats of oil based enamel.Awesome! Did you glass the outside of the plywood? The finish looks nice in the pictures.