I recently viewed a home with a garage that had a living space above it. The garage finished ceiling was comprised of 1/4 inch thick, 4 feet by 8 feet long sheets of bead board (pre-primed) Masonite material. The ceiling joists are 2 inch by 8 inch wood joist with a 3/4 inch plywood sub floor applied to the top of them for the living space above. Common practice used today is 5/8 inch drywall applied to the ceiling of the garage with 1/2 drywall on the walls adjacent to the home living space, right? My question is ...I feel that the 1/4 inch Masonite ceiling sheet panels does not give an adequate fire rating for today's standards. Could someone help with this Question?