The previous owner had done that because of the difficulty in removing ceramic tiles from a concrete floor
I took the bull by the horns and rented an electric jack hammer from Home Depot and in the space of a couple of hours I had it all torn out. Hot dusty work but it had to be done right.
While we were in Home Depot we bought "Pergo" type wood plank flooring that looks just like tile to put back down on the floor. We got enough to do the RV bathroom at the same time because the carpet in that bathroom was very tired and faded.
The house floor came out great and a new sink and vanity plus re-grouting the tiles around the tub made a HUGE difference.
While the bathroom was torn up we used the other bathroom in the house and the RV in the drive to take showers. Handy!!
Once the house was ready to show we moved the RV to a nearby campground and lived in it until the house sold.
The toilet in the RV had been leaning a little but now we were living in the rig the toilet sank into the floor.
I tore the carpet out and found that the floor was rotted under the toilet due to an old leaking seal (is this beginning to sound familiar?).
While I had the bathroom torn up we used the bathroom in the campground and took showers at the house (It IS familiar isn't it?)
The biggest problem was the floor flange which had been installed at the factory 16 years ago. They used 8 BIG screws to hold it down. They also set it down over the carpet and underlayment and drove the screws thru everything into the wooden floor.
Doesn't sound too bad except the leak let water soak into the carpet which held the water so that the screws could rust. The threads of the screws had grabbed hold of the carpet and pulled it tight to the flange. When I tried to remove them they were jammed tight. After a certain amount of deliberation and a LOT of bad language. I settled on soaking the top and bottom of the screws with WD40 and cutting as much of the carpet away from the screws with a box cutter. I used vice grips to hold the bottom of the screw (the flooring had disintegrated leaving the screws in the flange), and to give some leverage, I worked them loose. It took me the best part of an hour to get them all out.
I cut a patch for the floor, put a hole in it for the drain pipe then sawed it into 2 pieces centered around the hole so I could slip it under the flange. I made cleats out of the ply I used for the patch to reinforce the edge of the hole and to give the patch something to rest on then glue and screwed the cleats to the underside of the floor then screwed the patch to the cleats and caulked the joins to stop little critters getting in from underneath.
The flooring system uses a thin foam pad with aluminum foil on one side as a pad to insulate for noise and heat. That also lets the floor "float", Being a wood product it will expand and contract with changes in humidity. The foil lets it move without buckling.
The first board was the hardest with recesses for the door, a kick for the wall and a semi circle for the drain.
The other 2 boards had a 45 degree cut for the shower pan and various cut outs for the drain and a little pipe recess for the flush valve supply which though tricky were less trying than the first board. I had my arsenal of saws out for this job with a big hand saw, a tenon saw, a coping saw for the round cuts a circular saw I used at the campground, the big table saw and a scroll saw at the house. Then finally a hacksaw to cut the steel base for the threshold in the doorway.
That first board with the fancy cuts is closest to the camera
You can't even notice it's not just square
I really messed up the last board, I measured it right and cut the angle right, what I didn't see until I dropped it in place was that the "Grout" line didn't line up with the other ones. At that point I had 3 choices, either go with what I had or use the one I'd cut for a template to make another with the lines correct. We'd been without a bathroom in the house for a week and in the RV for almost as long and I folded and left it the way it was.
If lunacy should strike you and you would like to attempt something similar here are some tips:
Before you start empty the black water tank and wash it out well to stop smells in the rig. We had zero bad smells during the several days it took to finish. Stuff a rag in the waste pipe to keep debris out of the black tank and also to help keep smells out. Don't let the rag fall into the tank!!
If you are living in the RV find a spot to camp close to the bathrooms.
Measure the space and rough cut the boards a little oversized with power tools to minimize the amount of hand cutting.
Don't set your circular saw too deep when you cut into the existing floor. The black water tank is right below the floor and you don't want to cut into that. Check how much clearance you have beforre you cut. My black tank had about 1/2" clearance at the front and 4" at the rear I set the cut depth to barely go thru the 3/4" floor.
Plan out which board needs to be first according to the way the boards click together. You want to have room to lift the last board at an angle then press it together on the adjacent board. I worked from the door in - mainly to get the toughest cuts done first while I was fresh, but also because I would be able to get the last board in easier. I hadn't figured on the cabinet doors getting in the way so I had to remove the doors to get the last board in and replace them afterwards.
Use the "Wood" transitions between the carpet and floor they look great and are easy to install.
Be courteous to your fellow campers and don't use power tools when it will disturb other people I used hand tools mainly and saved the circular saw for mid afternoon when most people were out.