Maximum size: 48" x 48" (1219mm x 1219mm), maximum area of 2304 in², tolerance on height and width limitation is more or less 3" (76mm) as long as the area does not exceed 2304 in².
Temperature rise: 250°F (121°C) after 30 minutes and 450°F (232°C) after 60 minutes.
Fire rated access doors, for horizontal use, are subject to the following:
Rating Achieved: 3 hours in non-combustible construction and 1 hour in combustible construction
Maximum size: 24"X36" (610 mm X 914 mm) (hinges and latches on the side of 36"), tolerance on dimension limitations are more or less 3" (76 mm) as long as the area does not exceed 864 in².
Temperature rise: Within allowable per ASTM E119 and CAN/ULC S101.