We just installed a new Napoleon NZ3000 fireplace and are prepping the area to install manufactured stone around it. I am concerned about how to install the stone to the metal firebox. I am not sure if I should screw cement board directly to the metal firebox or just the lath on top of it. I would appreciate any information given. If you need any pictures or any other information, please let me know.
If you need to overlap, the cement board could do it in a more continuous manner, making it easier to thinset the stone.
Usually its either/or with lath vs cement board. Are you going to use both?
Properly secured board (8in OC) is sufficient for manufactured stone for a veneer and using thinset. Thicker stone using a mortar might want the lath support.