Searched for this for ages online before posting a question here. I want to set a few Culture Stone on Durock on an interior wall and I've read here - most notably from Tscarborough - that one can use a thin set to fix them on an interior application.
My question, which doesn't seem to be answered is how thick to put on that thin set - 1/4" trowel and butter the backs? Bigger toothed trowel? Those cultured stones are pretty uneven things so you're going to need some thickness to the thin set which may well get pricey.
You need enough, backbuttered, so that when you press hard, you barely feel the fake stone touch if at all. You may need to knock off the high points on the back. Do 100% coverage on the back of the stone, then run your trowel down the middle to provide some room to compress the mortar to allow for setting the stone.
__________________ Advice is free, Lessons begin at 75 bucks an hour.