A fire rated door is a specialized door designed to resist the spread of fire and smoke for a specified period, providing a crucial barrier in the event of a fire. These doors are constructed with materials that have high fire - resistance properties. The core of a fire rated door can be made from a variety of materials, such as mineral wool, which offers excellent insulation against heat. The door's frame is typically made of steel or fire - resistant wood, ensuring structural integrity during a fire. The door leaf may be composed of steel, composite materials, or fire - resistant glass, depending on the specific requirements of the application. Fire rated doors are classified based on their fire - resistance ratings, which are determined through standardized fire - endurance tests. These ratings indicate the length of time the door can withstand exposure to fire without allowing the passage of flames or excessive heat. Common fire - resistance ratings range from 20 minutes to several hours. They are installed in various locations within a building, including stairwells, corridors, and between different occupancy areas. In a multi - story building, fire rated doors in stairwells prevent the spread of fire and smoke, providing a safe evacuation route for occupants. In industrial settings, they are used to separate areas with different fire risks, such as between a manufacturing area and a storage area. Fire rated doors also often feature self - closing mechanisms and smoke - seals. The self - closing feature ensures that the door closes automatically in the event of a fire, even if it has been left open. The smoke - seals prevent the passage of smoke, which is a major hazard during a fire. Regular inspection and maintenance of fire rated doors are essential to ensure their proper functioning. Any damage or wear and tear can compromise their fire - resistance capabilities, so it's important to address such issues promptly to maintain the safety of the building.