First Timer - Subfloor Questions

[nick15]

Looking to add a floor to my 12' boat. I believe it is a 1976 Crestliner. As you can see, I'm going to cut down the benches and figure I can use them for some support. My main question would be how to add support to the middle of the floor. With there being no ribs, should I be riveting to the hull directly? I have a couple ideas but thought I would ask those with experience. I don't use this boat a a ton and I am not looking for anything fancy, basically just a piece of plywood lying on the floor. Thanks

 

[airshot]

One suggestion would be to add an angle (90) to the seat brackets or whats left of them and lay plywood down attached to those angles. I would screw it down so you can remove it easily. Just remember weight on a 12' can be critical.

 

[LDUBS]

Check out this thread for a unique solution:

https://www.tinboats.net/threads/easy-simple-24-‘flip-flop’-floor-for-a-tinny.50896/
Kind of blue sky and thinking far outside the box, I wonder if you could build a sort of big honeycomb out of foam board to support your ply floor. Would be lightweight and could just be put in place with the floor skin glued on top.

If I understand, you will be putting back part of the seat boxes on top of the new floor to replace the structural support you have removed?

 

[nick15]

My idea as of now is to do similar to how Dustin did on his build (snipped a picture from his post), and tie a couple supports from the floor to the side of the boat. Thinking something like @airshot mentioned, put some angle on top of what is left of the benches and lay plywood over that.

https://www.tinboats.net/threads/dustins-14ft-alumacraft-conversion-lots-of-pictures.24959/