I've used 6mm normal ply facing the road with a PVC cover around the edge all screwed to a frame. The original caravan had a thinner ply and didn't look to be treated with anything, but it was 20 year old!
Hi,
I'm converting a caravan in to a ship (not sea worthy) and we've rebuild the floor with ply facing the road. I've already woodstained all the wood we're using, but I'm not sure what to coat it with to protect it from whatever the road throws at it? I've thought about using bitumen and yacht...