Fire doors are metal, wooden or glass doors that are installed to prevent the spread of a fire through a compartmentation system and to allow rapid evacuation of the building. They are also known as RF (Fire Resistant) doors.

The main characteristic of fire doors is their thermal insulation property and their structural design that considers clearances to counteract metallic expansion resulting from increased temperatures, thus generating two thermal systems that protect escape routes.

The most common doors are metal pivoting doors. In these doors, it is tested that the temperature of the leaf does not exceed 140 °C on average, 180 °C at any point of the leaf and that the frame does not exceed 360 °C and on the other hand, the tightness to flammable gases is checked.

Fire doors are internationally classified by their Fire Resistance (RF). According to the average temperature resistance time in thermal insulation tests, they are classified as RF-30 (30min.), 60,...,120, 180 (minutes).

The insulating material inside varies depending on the fire resistance of the Door.

The hinges are of great importance. A hinge in poor condition causes forces of opposition to movement, preventing the door from being able to open or close easily in moments of expansion due to heat.

After one year of installation, it should be checked monthly that the door closes automatically and completely when left loose, and that the expansive or thermo-expanding intumescent tape is still correctly adhered to the frame.

Fire doors must be closed when necessary, therefore they must incorporate an accessory or closing system.

The effective protection of the fire door will depend on the operational strength of each of its components and the maintenance that is periodically given to it.

Every fire door needs preventive maintenance, which keeps its properties unchanged in the event of a fire.[1]​.

The maintenance operations to be carried out will be aimed at:.

Due to the characteristics of the components and additives that form the internal insulation of the door, the useful life is estimated for a period of no more than 20 years. It is advised not to exhaust this period if deterioration is observed in the door or its components.