Depends on what the surface is that your putting the veneer on.
Even if you use cement board, you still have to put wire lath over it.
I am doing 4 pallets of stone at the moment.
Over unpainted concrete, stucco or cement, you can mortar the stone directly to the concrete, just make sure there is no oils etc bleeding out.
Painted concrete, stucco etc, you need to use metal lathe.
Over cement board, plywood, foam insulation, etc. etc, the directions for Owens Corning Cultures stone I'm using says to use 2 layers of barrier, this is for interior or exterior.
I'm thinking the reasoning is mortar & stone do wick moisture out of the air which may cause the backerboard to rot, I dunno. But thats what my stuff calls for.
I used 2 layers of 15 pound roofing felt. If you going directly over open studs, you need to use the heavier mesh with the weather barrier pre installed to it.
On the painted concrete walls, I used Hilti shots with pins & washers to secure the lathe. Over the stud walls, I used some OSB board that was laying around, 2 layres of tar paper, the mesh, and 1/2 coat of mortar over the mesh, then buttered the back of each stone and set it in the mortar over the mesh. Sticks well.
The directions for the stuff I have gave several choices for going over the wood, foam, cement board etc,...... 1. mortar the mesh and stick the stones on, only doing enough that you can get it installed without the mortar drying.
2. Or butter the back of the stone & stick it on the mesh, 3. or mortar the mesh & butter the stones. I did option 3 , always overkill, but it holds.
My directions say very clearly, weather barrier on both interior & exterior. Yours may be different, I dunno. Better safe than sorry. The barrier is not expensive.
Its very tedious work. I'm using dry/tight stacked, and it took me 12 hours to do about a 5-1/2' x 5-1/5' area last night. Some type or design is easier than others.
