I have just stripped a kitchen down to bare walls & replaced the damaged drywall in the area where the backsplash will go (above the countertop & below the upper cabinets.
One section of the wall is brick with some kind of painted cement over it.
The part that will be behind the drywall was all cracked right down to the brick, so we used some rough-grained parging cement to fill it in and bring it up to close to the same level as the part that is smooth.
I now need to put a smooth layer over top that we can apply thinset and the tiles on top of.

Any recommendations on what would be best to use ?
I have been told not to use spackle, as it won't be strong enough to hold the tiles. Am unsure on whether I can use thinset to level the surface and then apply another layer thinset on top when it comes time to do the backsplash tiling (at least a few days later, long after the smoothing layer has cured).

Any help greatly appreciated.

Thanks. Patrick.

Your right, do not use any drywall compounds for filling the wall.

If you could post a photo of the area in question that would be more helpful in evaluating the repair area.

Without seeing it I would suggest using a modified thinset and stucco mesh to skim the area.
When you get it flat (by skim coating) you can install the tile. There's no other prep work needed.

Randall,
Thanks very much. A photo of the wall as it is right now at this link - Kitchen Wall photo

You can see the bare brick near the floor and the part where I have layered on some parging. I want to create a smooth surface level with the painted area before the kitchen cabinets go in so that the tiling will be that much easier when I get to that point (have to wait for countertop, etc).

Thanks. Patrick.

As I mentioned before, skim coat the parging with thinset to get it flat. Tape the inside corners with an alkali-resistant mesh tape and coat it with the same thinset.

Randall - thanks again. Have the modified thinset and the mesh tape. Will get at it as soon as the refinished floor is dried (and covered with hardboard).

Cheers. Patrick.

A quick update - here is the current state of the wall. Nice flat thinset ready for tiles ! Waiting for the countertop ...
Kitchen Reno - stage 2