Threshweld: I was one of the original posters in this thread and have had 5-6 years experience with wood floors I have made for first my Sevylor HF360 and then my Intex M4. Eventually I outfitted my M4 with removable pedestal swivel seats and was very comfortable throughout. Both times I used 15/32" standard plywood, well sanded, with 2-3 coats of quality outdoor primer paint. I fished in the rain and often got the floor soaked. Occasionally the wood got minor chips in places though that was probably from storage, transport and assembly/disassembly on the shore, as I never used a trailer, often fishing several weeks in a row. I think I did one other coat a year or 2 into it, to spruce it up. Wood splitting or warping was never an issue, nor was the paint coming off or wearing through. I'm sure I have several photos of my floor boards on this thread. I know I just located some for my HF360 on page 4. I wouldn't change a thing, including having no piping, no hinges and only a 2 piece floor. I did add a small (~12"-18" x ~6"-12") 3rd piece for the nose of the M4 from leftover wood, to tighten it up a bit. Depending on how much you plan to stand in your boat you MIGHT want to go very slightly thicker with the wood, though I wouldn't have. Much more is overkill only adding weight. Good luck. Dave