So, last year I built a dump druck. I bought an 88 Chevy c70 chasis. It needed a little work, but soild for the most part. I then found a used bed and hoist. The guy that I bought it from took the old wood sides, and old wood floor off. He didnt charge any labor to do it, and it made his job easier. I ran out of time last year to do it, but i was going to have the bed sandblasted and repainted, put a wood deck on it, and then weld a sheet of 1/4 inch steel on it. It never happened. I go the wood deck on and that was it(I did build the sides to). So, this year, I thought I'd put that sheet of plastic on it instead of messing around with the metal. What do you think? My other question is, do you bring seam to seam, or do you overlap them???