Building the back wall for my wood stove which I to attach cement board and stone veneer. The steel studs when used for regular construction building a wall the studs are used singularly which is naturally common sense....ok. But when building the back wall should I double up the studs to accept the weight of cement board, veneer mortar and a field stone style of veneer? Also should the the steel studs be secured where I'd have about an 1 1/4 space as to the other way with the stud allowing a 2 3/4 space. I know a min. of 1" is required space and was also informed that not to use a long screw that would secure the cement board and studs into the wall of the room it's being installed due to heat transferred to the homes original wall structure.