It is time to refurbish my utility trailer. I need to replace the wood sides which are literally falling apart and the decking as well as clean up rust on the frame and repaint the frame. The current deck is 3/4" PT plywood which lasted probably 10 years (I'm the second owner). I really don't want to use plywood again because its deterioration rapidly increased by me moving tools and other stuff that gouged up the surface. With solid material such as PT wood or composite, I don't thing that'll be nearly as much trouble. I'd still like the bottom to be splash-proof though, which means no space between the decking boards. My two ideas are to use PT lumber with a rabbit cut on each side and overlap to allow for shrinkage. That sounds like a lot of work, especially since the lumber won't be straight. The other thought is to use composit decking, put a bead of silicone caulk on each joint, and butt the pieces together. My only concern is that the 2x2 steel crossmembers are 2' on center rather than 16" on center like a deck would have. Any thoughts or experience with this stuff?