soft floor replacement
I replaced tha section of my bathroom floor by cutting out a 24" by 42" piece of the sub floor. I went to the middle of the frame stud about a inch and a half to the right of the sink base and all the way to the street side wall. I used one of those osolating tools from harbor freight ($39.95), it worked great for keeping a strait line and not going too deep to cut the waste tank.
then cut the grey water drain pipe to remove it, 3" from the sink base and 3" from the tub front wall. then cut a piece of 3/4" marine plywood and coated the outside with spray undercoating, cut out the drain hole and vent tube hole. and put a 3/4" angle recessed on the front edge of the original floor. then I covered the whole floor with a 1/4" piece of luan (plywood) to make sure everything was level, then installed a new sheet of simulated wood plank vinal flooring. had to wait a few days until it was warm enough(above 65) so the glue would work well. then replaced all the fixtures,replaced the drain pipe with 2" connector compression sleeves and it works great! now i am checking for all the leaks that the previous owner hid from me that caused the problems. I think I will replace all my cone seals so I won't have future problems. after that, a good cleaning and its off to camping season for me!