I have the exact same project going on, only with a 16' Starcraft. I have put floors and casting platforms in semi Vees and Johns before, so have a little experience to offer.
1) Take the posters advice about using marine grade plywood. Worth the few extra bucks. I plan on this current project to also seal the boards with urethane or fiberglass before riveting them in. And avoid the temptation to go with super heavy thickness like 3/4 inch - just adds unnecessary weight which you don't want in a light aluminum boat, and also causes the boat to lose steerage (been there). I'm using 1/2 inch on this project.
2) Make sure the hull is tight before putting the floor in. Pulling out a second batch of 5000 rivets (well. a large number anyway) is no fun. On my boat I sealed all seams inside and out, and about to apply an 2 part epoxy airboat type paint to the bottom - super slick and tough to handle the rocks in the lakes and rivers I fish.
3) Think through your wiring and plumbing before you lay the floor.
4) Stringers - if you are going to install these to make the floor flat, use the upside down U-shaped "channel" tubing. great weight to strength ratio.
5) You are going to need to consider flotation. I recommend googling this. I'll probably go with foam encased in plastic sheeting to keep the squeaks down.
6) what to apply after the floor is in. Some folks use bedliner, but I don't like the black color, it absorbs/reflects too much heat. There are marine paints with the sand type finish in various colors.
7) I don't think I'll go with carpet or vinyl, although that is also an option. I have found over the years that carpet is bad - it just soaks up moisture and makes the plywood soggy.
Good luck with your project!
Blu_Cs
