Mods, if you want to move this to automotive I understand. Put it here because it is more of a joinery question than an automotive one.
Anyway, I have a horse trailer that needs the floor replaced. The floor is made from a single 7' X 12' piece of 1" thick marine grade plywood. Floors for this trailer are no longer available in the US and would cost over 2k to get them imported. For structural integrity, the floor must be one piece.
So, is there any way to join 3 4 X 8 sheets into a large sheet such that they would have the same strength as a single sheet? I had thought of using a finger joint with resorcinol glue to hold it all together. Then possibly screwing some galvanized sheet metal to either side for reinforcement.