I have a really odd set of questions / problem and I need a bit of help from some experts. I am attempting to refinish a room for my aging mother who has bad knees so I can put in a full-sized 4-person hot tub so she can soak and take care of some of her pain. I have already purchased the hot tub so we are set. The space is an indoor breezeway that is fully enclosed (10' x 22'). We were using this space for a den and laundry room but now it will be laundry and hot tub. I just removed the carpet and padding on the floor and found tile. Underneath of the tile there is three concrete slabs that make up the floor. No basement, hence why it’s ideal for the hot tub and it’s the first floor so she doesn't have to go up any. The tile is 8" squares, and more than likely vinyl-asbestos. I do not want to remove the stairs or be outside. My situation is that the three slabs (each 10'x7' roughly) have shifted a little bit and sunk down from each other. Not big mind you, like the first slab segment is fine and level, but the second one is 1/8" lower than the first, and the third is another 1/8" lower (making the 3rd almost 1/4 lower than the first) again each slab is level to its self, just lower than the first. So my first question is how do I level these slabs? My first idea was simply to use 1/8" thick of plywood for the first of the lower segment cutting it to size, then a 1/4" thick plywood for the second of the lower segments. This way making all three all level with each other, or at least closer than it was before. The second way is a lot like the first., just using 1/8" of plywood to bump up the 3rd slab, then a bigger 1/8" plywood piece(S) to bring slab 2 and 3 up to 1 if that makes sense. Now I was also told I may be able to do this simply with foam padding but I am unsure. If I do either do, I need to put any sort of adhesive on under the plywood between it and the tile floor? Next question is what do I need to cover or encapsulate the asbestos title with? Is there some sort of paint or or brush on liquid covering? Or should I simply put down a vaper barrier and then a foam pad for under the flooring product I am going to place down? Last question since I am dealing with concrete and putting a hot tub on the floor which may splash some water around what product (laminate, vinyl, tile, ceramic, bamboo, etc.) would you suggest I use? Like to get something affordable, because I am coming out of pocket to pay for this all for her but will wear well and not get moldy or mildew in case it gets wet. Feel free to email me directly sdpinc AT comcast DOT net since I don’t know when I will be able to log on next. Thank you all so much for your time and help! I really need to do something to help her out and your helping to make that happen!
Best regards! Mike

I can't speak much to the plywood/subfloor work you need to do, but I can recommend a product - basically you want to stay far away from any hydroscopic material, so no laminate or wood products. The reason being that the humidity in that space will be sky high due to the hot tub. You WILL have issues with glue adhesion and lifting material if you go that route. My recommendation would be to tile the whole area and treat it like any washroom or laundry room, which means PROPER VENTILATION to remove the humidity is a must. Expect that there will be a lot of water splashing and standing on the floor. Make sure to install a floor drain if there isn't one already.

Good Luck with your project!