My bathroom is tiny. The floor is 20 sq ft plus the bathtub. House was built in 1947 and I have removed 3/4 of the (likely) asbestos tile. History: I came across a free MSM green toilet and sink and had to have it. I paid a guy to put the toilet in and demo the sink and vanity and he put in cement board and tiled a back splash and surrounding tile for the new vanity that he had intended to stick build from scratch to support the new sink. I paid him for that and that was 2 weeks ago and I still have no sink installed. Then I decided while I was waiting for him to come back and finish the job, that I would go ahead and fix the floor. I removed the 3 layers of linoleum and asbestos under-layment. Since I don't know if he is coming back or not, I have been researching what it would take to finish the job myself. I went shopping at Lowes and picked up some wood look plank tiles that I like and after watching a youtube video, I decided to go with Laticrete Strat-mat uncoupling membrane underlayment instead of hardy backer. My reasoning was that with the tile being 1/4" and the cement board being the same, that would be a full half inch difference with the hard wood floor in the hall and the Strata-mat is only 1/8". Problem is everything I've read thus far online indicates that I need to remove the hard wood planks down to the sub-floor and then install. When the install guy and I had discussed floors, he said I have to have an inch of sub floor with hardy backer on top or the movement would crack it. The guy on the video responded: Yes, you need to demo to the subfloor, sponge the wood subfloor and install the Strata mat. You don't need 1 inch of plywood for your subfloor. We install on 5/8" or 3/8" subfloor all the time with Stratamat. I have no intention of removing the tub so that I can tile underneath it. So my dilemna now is, do I go with the original plan and use a 3/8 transition threshold or do I demo the hard wood and install on the subfloor? Being a total rookie, the only way I can think to demo the planks is to adjust blade on the circular saw so that I don't dig into the sub-floor and saw a rough square around the perimeter and pull the old planks out. First issue there is I have no idea how thick the planks are. Second issue is, that is going to leave wood extending from underneath the tub that I would have to get out of there somehow. Wood chisel? Third issue is, that whole process is going to leave the tub on top of wood plank flooring and I have no idea if the it is safe or if it's leaving the tub unsupported or less supported. I hope I have come to the right place. After this I will have to figure out how to wall mount an old Standard sink, but that's a different issue. Thanks in advance for any advice.