Few years back my SK began to take on a water leak which ended in the driver & passenger side foot-wells. Checked all suspect spots & sealed possible entry points which minimized the water flow but did not stop it. I made the mistake of not removing the carpets which caused the floor to begin to rust, so this summer I decided to remove the bench & seats & look under to see what work needs to be done. The floor was in bad shape. The floor is supported by braces which cross the frame's main cross beams. In the middle the floor was solid but at the edge where it meets the doors the metal was gone. There are no cross beams in that area where support to the floor can be attached. Having no welder I had to find a way to install some kind of a brace to the floor. I decided to use L brackets. 8" L brackets, bolted to the main cross beams, supporting metal plates placed under the floor. The floor is bolted to the plates, & where ever there's space between the floor & metal underneath (due to the braces) I used 3/4"-7/8" pieces of plywood as spacers. All rusted areas of the floor were treated with rust converter, sealed with fiberglass, & sprayed with rust proofing paint. I installed plates where ever the floor needed it, but you could place them end to end & fiberglass the entire area. Small pieces of glass work best. Total cost for the repair was about $200. The floor is now quite solid. It should be inspected every spring & reinforced as needed.
My Side-Kick will live to ride another day.