Rachael you will eventually have water damage to the wood floor no matter how careful you are. I also have a cast iron tub that i used as a child and would like to put in my bathroom. I now have immatation marble around the existing tub. My mother put wood floors right up to the shower and tub. When I moved in I put ceramic tile because after only 5 years the floor was darkening from water. I would suggest you put different floor under the tub. My ceramic tile looks good with the wood and has saved having to replace it. Hope this helps. I have lived with wood floors for 55 years and wouldnt have anything else but it is not practical in some areas. Boots Harrold