Standard Fire-Rated Access Door for Walls & Ceilings. Stainless Steel Door and Frame, 2 1/2" deep, insulation is 2" thick mineral wool (ThermaFiber®), in between two pieces of Stainless Steel. Williams Brothers Stainless Steel FR 800 Series Standard Fire Rated Access Door This Fire Rated Access Door can be used wherever it is necessary to provide service access to shafts and any other...