Enclosing areas with fire barriers — fire doors, walls, ceilings and floors — is the best means of containing fire. Fire barriers play an integral role in managing a fire by interrupting the spread of smoke, toxic gases and the fire itself from one fire zone to another.

What is a Fire Door?

Not all doors are fire doors. The Life Safety Code stringently regulates fire doors and their closure, precisely because of their importance as passive fire protection devices.

Fire doors are composed of a combination of materials, including steel, gypsum and other fireresistant materials. Some fire doors are equipped with windows, which must be subjected to product certification. Fire-resistant windows may include wire mesh glass, liquid sodium silicate (or “water glass”) between two window panes, ceramic glass or borosilicate glass.

Every approved fire door will have an assigned fire rating determined by a standard fire endurance test. The fire rating is stated on the door’s label, and indicates the door’s ability to resist the passage of fire and hot gases. The fire rating of the door is determined by a standardized destructive fire endurance test on a sample door.

Fire doors are fundamental to the integrity of fire barriers, because any time there is an access portal (such as a doorway) to a compartment, a fire barrier is broken temporarily. To minimize the break in protection and the spread of fire, smoke and toxic gases, fire doors must be self-closing and have proper latching devices.

When Are Fire Doors Needed?

In general, fire doors are needed whenever a door opening is present in a fire wall. Fire doors are also needed when a door has an “Exit” sign on or near it, when a door leads into exit stairwells and horizontal exits, or when a door leads to a hazardous area such as a room used to store flammable liquids.