We are building our house and are looking for advice about best practices to prevent drywall cracking in the "attic rooms" that will be built into the designed living space of the engineered trusses. We basically have a 14'Wide X 60'Long X 8'1"Tall space that will be the living area of our house; this is the "room" in the clear span engineered trusses over a 40' X 60' garage. The trusses are designed and rated for the proper live load and are spaced on 24"centers. The subfloor is tow layers of 3/4" plywood glued and screwed into the trusses. Originally I planned to use 1 X 4 furring strips on 16"centers up both knee wall and across the ceiling to fasten the drywall to, but I am now thinking that sheathing it completely in 7/16 OSB, glued and screwed to the knee walls and ceiling ( and then fastening the drywall to the sheathing, screwing into the "studs") would make a stronger structure and be less prone to movement and subsequent cracking of the drywall. What do you think?
I'll try to attach a couple of pictures in case I haven't described it well.