On my 20 ft dovetail trailer I am kinda tired of using pressure treated pine just to have it break at a knot when loading something heavy. I was thinking about cutting some oak for the floor, my question is what can I use for a rot preventive , I have seen copper sulfate but they suggest soaking anything about 2 inches thick, well I need to cut at 16 ft. do not have desire to make a trough and fill with copper sulfate at what a cost. Do you guys got any ideas. I want to stay away from paint , to slippery, but I guess I could add sand to it. thanks Dave