Go to the bathroom and get on your hands and knees and feel the floor around the toilet. Feel the floor under windows, and in closets Also open the back area and feel the floor. I have read about floors becoming rotten because of leaks. I had to replace my whole bathroom floor. I have been working on my 1973 Overlander since last fall. No regrets because it has been a fun project. I have learned a lot about hands on maintenance. It has gone smoothly because of all the knowledgeable people in this forum. One place to start reading is in Forums Replacing the floor and fixing the frame.