We are going to take down the existing tile around our gas fireplace and replace it with natural veneer stone (not cultured or manufactured) that will go from floor to ceiling (including a hearth). It will also wrap around the sides.
What's the best process? We are thinking..
1. Cement backer board
2. Waterproofing paper (what kind is best?)
3. Metal lath
4. Scratch coat of mortar
5. Back-butter individual pieces of veneer stone
We like the dry stack look so I don't think we need to squeeze mortar into the joints, right?
Does that process sound right? I am wondering if we can get away with skipping steps 2, 3, and 4 and just directly back-butter the veneer stone onto the cement board.
I wouldn't use cement backer board, unless it's already up & salvageable I guess.
For this very application, and assuming that these are smooth, dense, sawn-back stone, a good modified thinset adhering the stone directly the backer board would be OK.
Also, installing galvanized diamond mesh over the drywall, or w/e is under teh brick, with a coat of plaster would be fine as well. I'd suggest literally "scratching" the scratch coat as well, just use a notched tile trowel or similar. Let the scrratch coat dry overnight, and you should be able to stick the stone with a typical Type S or N with a few oz. of bonding agent mixed into each batch.
Lastly, drystack can be relatively complicated for a natural thin veneer stone, as the stone are usually heavy enough that they will slide down the wall when wet w/o support from the stone below. For this reason, I think the thinset approach "may" be the best approach.