How do the levels of the bare concrete and wood subfloors compare? It's hard to tell from the video. Are they level with each other or is one higher than the other?

The concrete seems to go down several inches below the subfloor. At least it does in one area...

I'm guessing that I have two choices:

1. Use something like a jack hammer and remove all concrete and then build-up with wood then plywood to match the level in the kitchen or...

2. remove the tile only then "float up" the concrete to right level to match the kitchen.

I believe that the underlayment + 1/4" Hardibacker will have the kitchen floor a tad higher than the concrete just below the tile. If so, maybe option 2 is better. Not sure if there might be other choices and factors to consider...

Thanks much.

If your slab is slightly lower than your wood floor, you can add something like DRIcore or Delta FL, which basically put a wood subfloor on top of concrete.

If it's several inches lower, then you could fur it up with 2x4s that you rip to the right height, then put plywood over top of it even with the kitchen subfloor.

If it's not level, then it's a whole 'nother ball game, and you'd probably best tear it out or build it up.

One thing I'm not sure about, and perhaps a pro will jump in, is whether it's wise to tile across a joint between wood and concrete. At a minimum I'd use Ditra instead of hardibacker (I'd use Ditra anyway, as it's a lot faster and easier than hardi). But you might also need a joint where the 2 subfloors intersect.

Here is a link that might be useful: DRIcore info

I'm not a professional, but it looks similar to what we ran into in our entryway of our 1959 house ... the tile in the entry was in a "mud bed" (or mortar bed) which was a thick layer of mortar with a metal mesh webbing behind it. Of course, I didn't find this out until the night before the floor installers showed up, when I was going to "chip out the tile" quickly so they could keep a level surface throughout all the areas. Ha! It did require a jackhammer (we later did a bathroom and purchased a tool called a hammer drill which worked well, if on a smaller scale than a jackhammer). Then we built up with plywood to be flush with the other areas, but we were putting down hardwood, not tile. I've used the Ditra mat, too, for tile, and it has been good for keeping floor from cracking in our shifting soils.

I think the mud bed in our entry was three or four inches deep.

Good input guys. Thank you very much!

I've had a couple tile guys come out to provide quotes, just one moments ago. His thinking was to mud or mortar the whole thing, including the kitchen, so no Hardibacker or Ditra, which I was leaning toward... I guess the benefit there would be the ability to make the elevation the same in both the entry way and kitchen... It would 1/2 inch though, on top of the underlayment, then thinset, then tile. That becomes higher than anticipated, and possibly problematic with respect to a transition to carpet in the living room and the DW fitting under the counter.

The other tile guy would jackhammer the mortar bed, remove it and use wood to build it up. He'd use 1/4 Hardibacker, however nail those down with roofing nails. He does put some thinset on the bottom of the Hardibacker though. Not so keen on roofing nails on the Hardibacker, but maybe with the thinset under, it would be fine....

If it's a mortar bed, not a slab, then I'd vote for removal. I pick tiler #2, but screw down the hardi instead of nail (show him the manufacturer's instructions). Better yet, just go for Ditra.

Thank you weedyacres.

Before I realized there was no subfloor in the entry way, I was going to do the tile work myself, and use Ditra. I had used Hardibacker before, but after some research, I liked what I had learned about Ditra...

When I asked the tile guy about why he uses roofing nails, he got defensive. I actually had a Hardibacker type screw there to show him, and I sensed that he felt it wasn't necessary. Not a good feeling. And although I'm sure he'd do so for me, I'd imagine he would not be particularly happy using screws...

Since I'm comfortable doing tile, I just need to remove the mortar bed. It's a 10' x 7' entry way and appears to be a few inches deep. I guess I can rent a jackhammer or maybe even buy a cheapo one such as below.

Here is a link that might be useful: Breaker Hammer