I am replacing the floors in my '77 Sanger and i need a little help. When I removed the existing floor i had to remove the foam that was under it as well due to water damage and now I don't know what type of support to use under the new floor. The is not any suppot in the middle of the floor, only one stringer on each side. I was thinking of adding some cross members across the stringers but i was told that was not a good idea because it may not allow the boat to flex when it needs to. Any help is appreciated. Thank you