Slab on Grade - Hardwood Floors

[diiulio]

I am a little stumped on how to proceed properly. I am tiling my kitchen. I have tore up 5 floors of tile and linoleum. The room is approximately 22' x 10'. I have a door to the garage and a door to the dining/living room. Previously I had a 3/4" transition from the tile in the kitchen to the hardwood in the dining/living area.
The house is a slab on grade. The adjacent floor is 6 mil poly, 3/4" floating plywood, tar paper, and 3/4" hardwood flooring on the concrete slab. So, I have about 1-1/2" height to match.
I have already purchased Ditra XL because I didn't think I could put plywood or cement board down on a slab on grade. I was going to accept the 3/4" transition even though I hate it, but now that I slept on it I don't want to deal with it. Plus I am selling the house next year and don't want to have a poor install that will turn off perspective buyers.
So, now I am thinking I should put down a 3/4" mortar bed, float the ditra XL, then install tile. I realize I could put down a 1" to 1-1/16" mortar bed and not use Ditra XL, but I already purchased it for over $600 on line and it will be here tomorrow. I guess I could ship it back and pay for the shipping back. I bought two rolls of 175SF of Ditra XL 5/16".

I need some advice, please.
Questions:
1. Do I install 3/4" mortar bed and then Ditra XL?
2. Do I install 1-1/16" mortar bed then tile?
3. What is the best mortar to use that I can get at HD or Lowes?
4. How many bags do I need for 3/4" on 220SF (figure 1/2 CY)?
5. Do I need a bond breaker (tar paper) below the mortar bed to the concrete?
6. Do I need to shoot some nails through the wire mesh to the concrete? How often?
7. What do you do for edging where the mortar meets the drywall? I was thinking a strip of 1/8" that I will pull up after I screed it.

[cx]

Welcome, Jason.

1. You could do that.

2. You could do that.

3. Don't know what your local stores might carry and we don't know where local might be as you've put no geographic location in your User Profile. Quikrete and Sackrete are common home center brands of such products.

If you'll visit the Shower Construction thread in our Liberry you'll find information in a couple places on how to made deck mud.

4. That would depend upon how big your bags are, eh?

5. No. You want to bond your mortar to the slab using a slurry of Portland cement or thinset mortar.

6. There will be no wire mesh.

7. You could do that. Some folks use a foam strip and just leave it in place. You really want a larger gap than that. A quarter-inch is good.

My opinion; worth price charged.

[diiulio]

Got it, thanks for the feedback. Much appreciated.
I updated my info for location. I am just outside of DC in Virginia.

I have already purchased the Ditra so should I use it? Is it worth the $600 or should I just screed 1-1/8" and return the Ditra? This is the question, is 1 or 2 better?

I am thinking I will need around 28 bags of 50# sand and 5 60# bags of cement for a 3/4" depth across 220SF. Based on a 5:1 sand:cement ratio. I can use 1/4" foam strip around the edges, that works.

Do you keep 1/4" off the threshold also?

[diiulio]

OK, so I tackled putting down my first 220 SF 3/4" high mud bed. Laid down 5/16" Ditra XL, then 12" x 24" tiles on a 50/50 brick pattern with minimal cupping of the tiles. I used 1/4" spacers. This was all on a slab on grade with adjacent room of 3/4" plywood and 3/4" hard wood. Goal was to be flush with hardwood, but I ended up about 1/4" higher than the wood. Slight kick in the pants, but not bad.

My threshold gap that I left is 2-1/4". What do you recommend for install? See pic and attached plan. I plan to cut out the extra mud bed so it is flush with tile, rip a piece of 3/4" plywood to laydown adjacent to existing 3/4" plywood subfloor, the cut a custom wood threshold and nail down to existing subfloor and new subfloor. Leave about a 1/4" gap to the tile and fill with caulk that matches the grout. I figure I would leave the add'l 3/4" subfloor floating to deal with any expansion and contraction.

Does this make sense? What is the best way to make a custom threshold? Also, the door gets no trim, it is as you see it.

[diiulio]

I'm having a tough time having the picture show up.
http://im1.shutterfly.com/media/47a4...D720/ry%3D480/

http://im1.shutterfly.com/media/47a4...D550/ry%3D400/

http://im1.shutterfly.com/media/47a4...D550/ry%3D400/

[cx]

Jason, it'll help if you'll keep all your project questions on one thread so folks can see what you're working on and what's been previously asked and answered.

It'll also help if you'll attach your photos from storage on your computer so they appear in your post and don't disappear later. Use the paper-clip icon above the Reply dialog box. We can remove your other posts once you get the photos properly posted.