I'm going to be installing a safe in a somewhat hidden area in the back of a closet. There will be about 8 inches of space on either side. I was wondering if layering sheetrock/gypsum board in the voids outside the safe on the sides, top, and back would help in fire protection. This would be 10 or 12 layers surrounding the safe except for the front. Would the exposed front side negate any benefit that the insulated other sides provide? If the usual interior gypsum of most safe walls provides fire protection by releasing moisture into the safe to lower internal temperature, would the exterior layers of gypsum be a waste of time. Other than concrete block, do you have any other suggestions for fire protection.