I used E-track brackets to lift three 2x4's across the width of the trailer, and then I mounted a 1/2" plywood panel across the 2x4's. The panel was roundover routed to make a smooth roll-off edge,sanded, and then I foam-rollered two coats of oak-tinted polyurethane. Works great! I need to screw the platform to the 2x4's though.