I've got an 8x10 aluminum tilt-bed snowmobile trailer (but no snowmobile) that's used to mostly haul lots of brush, lawn tractors, motorcycles, ATV, and misc big and/or heavy stuff that won't fit into or is too heavy to load into the cap-covered bed of my truck. It gets a lot of use. It also lives outside, parked over grass (no room for it inside). I replaced the decking about 6 years ago with generic 3/4" plywood that I'd put a couple of coats of Cuprinol (or something similar) top & bottom. It's held up pretty well, until recently when one corner broke way from the screws and it warped into a 4" high mini ski jump at the rear. It would have probably lasted longer if I'd continued to apply some kind of preservative to the wood, but that ship has sailed. I don't think that it's practical to use anything but 3/4" ply on this trailer, but I could be wrong. I don't want "expanded" or sheet metal for sure. So I'm wondering if there's a particular type or grade of ply, and what to coat it with for preservation as well as helping traction. The ply has gotten slicker lately and I've had to make a few attempts to get my lawn tractor up past the tip-over point to get the bed horizontal (yee-hah!). Suggestions welcomed! Thanx!