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A 'fire door' is a type of door, or 'closure' used as a passive fire protection item within buildings to prevent the spread of fire. It is usually the only means of allowing people to pass through a fire-resistance rated wall assembly.

Contents

Components

Door Hardware

Seals

Windows

Regulations

Combustibility

Defeating fire doors

Normal operation

Trade responsibility

Architect's responsibility

See also

Components

'Fire doors' are made of a combination of materials, such as:

★ steel

★ gypsum (as an endothermic fill)

★ vermiculite-boards
Together, these components form a system which holds the rating.
Apart from the ''door leaf'', there is the ''doorframe'', the ''door hardware'' and the ''structure'' that holds the fire door assembly in place.

Door Hardware

Door hardware includes, but is not limited to:

★ manual or automatic closing devices

★ locks

★ latches

★ hinges

Seals

Edges of a fire door usually need to have fire rated seals which can be composed of:

★ An intumescent strip. Which expands 600 times under heat

★ Neoprene weatherstripping

Windows

Some fire doors are equipped with internal windows, which must, likewise, have a rating or have been incorporated at the time of the door test and be subject to product certification. Fire-resistive windows may include:

★ wire mesh glass

★ liquid sodium silicate fills between two window panes

★ ceramic glasses

★ borosilicate glass
to perform well under fire conditions and/or to provide impact resistance. Wired glass typically withstands the fire, whereas the sodium silicate liquid also acts to insulate heat transfer, due to the endothermic action of this chemical.

Regulations

All components are required by law to adhere to bounding requirements in product certification that is acceptable to the local Authority Having Jurisdiction (AHJ) by meeting the requirements of the local building code and fire code.

Combustibility

Fire doors are not necessarily all noncombustible. A fire door is but one of many passive fire protection components used to compartmentalise fire and thus keep it in the compartment of origin, so either it runs out of fuel or it is extinguished, or, at the very least, enough time has been bought to enable evacuation of the building.

Defeating fire doors

Fire doors are routinely defeated by unwise actions and apathy on the part of their users, many of whom paint over and/or ignore the product certification markings that are prominently displayed both on the door leaves and all the fire door frames, by blocking them open and even running carpets through them. Such extreme neglect is the legal responsibility of the building owner, who must educate occupants on the safe use of all safety related items, to ensure compliance with the fire code.
Sometimes fire doors have apparently very large gaps at the foot of them, an inch or two even, allowing air movement, especially in dormitory facilities. This can lead the occupants of a building to question their status as 'real' fire doors. Presumably this doesn't allow fire to spread significantly.

Normal operation

Most fire doors should be kept closed at all times, however some are designed to stay open under normal circumstances, only to shut automatically or manually in the event of a fire. Whichever method is used, the door's movement should never be impaired by a doorstop or other obstacle. Proper bounding of fire doors should be routinely checked and ensured.
Some fire doors are held open with an electromagnetic coil, which may be wired to a fire alarm system via relays. If the power fails or the fire alarm is activated, the power to the coil is cut and the door closes on its own.
Rated fire doors are tested to withstand a fire for a specified period. There are 20, 30, 45, 60 and 90-minute-rated fire doors that are certified by an approved laboratory (e.g. Underwriters Laboratories). The certification only applies if all parts of the installation are correctly specified and installed. For example, fitting the wrong kind of glazing may severely reduce the door's fire resistance period.

Trade responsibility

The building trade typically responsible for door installations is the carpenters.

Architect's responsibility

In building design drawings with poor identification of which walls do in fact have a fire-resistance rating, it is often necessary to check the door schedule in the specifications to be able to trace what walls are rated and how long they are rated for. This is an indicative sign about the architect and the degree of care taken particularly with items relating to passive fire protection. To avoid confusion about any fire protection measures including fire doors, it is best for the architect to provide a separate set of drawings that clearly outlines which walls and floor have a fire-resistance rating and exactly what that rating is. It is also important to point out especially which walls are firewalls and which walls and/or floors are designated as occupancy separations, as the nature of passive fire protection devices that must be used in those special cases can be substantially different from such devices that are used in ordinary fire separations.

See also

★ Fire-resistance rating

★ Fire protection

★ Fire test

★ Passive fire protection

★ Certification listing