I built this fireplace surround about 4 years ago. It is 9 ft tall, by 80 in wide. The main section is 24 in deep and the hearth extends another 16 in. I just got done supporting the joists below and transferring the weight down to the concrete basement floor. Ready to start putting this stone veneer up but I'm wondering if this cement board is going to hold it? I used 1/2" Permabase screwed in with 1 5/8" scorpion cement board screws into the wood framing. The veneer I'm using is made by Stonecraft and each piece weighs an average of 3 to 10 lb each depending on the size and some of the corners go up to 17 lbs.
'As I'm getting ready to add the fibre tape mesh over all of the seams and corners I'm hesitant to do so yet because I'm wondering:
1) what would keep the weight of the stone from ripping the cement board off of the screws? All together I'll probably end up with about 1200 lb of stone plus whatever the weight of the mortar is.
2) I've seen videos of some installers using construction adhesive behind the board on the framing before putting the cement board up but I did not do that at the time. Is that necessary? And if so, could I even do that at this point without ruining the cement board since there will be a bunch of holes in it that I will not likely be able to reuse for the screws?
3) On the ceiling of the arch, where the stone is going to be hanging, I used large kerdi washers to help pull the boards in to shape. Do I need any extra reinforcements since the stone is going to be hanging? Or should the mortar bond it in place?
4) And what about on the white non-combustible board attached over the gas fireplace insert? Will that hold or should I add metal lath over that?
5) I purchased five bags of Laticrete multimax lite as my supplier told me it is good for heavy tile and stone applications. What have you guys used and do you think this should be sufficient?
6) Last... would it be recommended for me to attach angle iron around the perimeter of the gas fireplace insert to use as something to butt the stone up against? The manufacturer told me to keep all of the stone a minimum of 3/4 of an inch away from the fireplace cover and I sketched an outline around it but thought maybe it would be cleaner to put something there.
Thanks again for all of your advice. Photos below for reference.
