Fire doors ultimately prevent flames and smoke from spreading in a building by restricting the oxygen supply. When installed to correct standards they make it easier to evacuate the building or locate and extinguish the fire before it gets out of control.

Intumescent door seals

An intumescent door seal expands and swells when exposed to heat. They seal any gaps around the door to prevent the fire from spreading any further. When combined with a fire door, they will protect the people and the building on the other side of the door for 30, 60 or 120 minutes. These seals are fixed into grooves in the door leaf edge or in the door frame using adhesive.

Smoke isn’t always hot enough to activate the intumescent seals, so an integrated brush seal is added to prevent cold smoke from passing through the gaps. Smoke is more dangerous than fire, it spreads at a much faster rate and when inhaled it can kill much quicker than fire.

Overhead door closer

An overhead door closer is essential on a fire door. They enable a door to close correctly after use, creating a barrier. This way the building is split into sections which compartmentalise fire and stops it from spreading. Todays modern closers close softly rather than slamming shut, reducing the risk of trapped fingers, but more importantly this mechanism reduces the risk of damage to the fire door itself.

Overhead door closers come as a box that mounts to the door with an arm fixed to the frame. Hidden overhead closers are also available if you do not want any bulky mechanisms on show. It is important to note that with hidden closers intumescent seals would need to be used with them to ensure the correct protection.

Floor springs

Floor springs are another form of door closer which are almost invisible because they are fitted to the floor. They are a good alternative to standard door closers; the minimalistic design makes them adaptable to all architecture. Door springs can bear heavy loads and therefore they do work well with oversized doors.

Fire door holder

A fire door should never be wedged open, however in areas such as schools and hospitals, where there would be a high level of traffic, it is practical to be able keep a fire door open. An electromagnet can be mounted onto the wall or an automatic door closer will hold the door open and upon trigger of the buildings fire alarm going off, the door will close itself. These type of closers can be connected to a buildings fire alarm system through the mains or radio controlled through an electric link to the fire alarm system; pretty high tech stuff!

Intumescent locks and hinges

The lock is seen as the most secure part of the door. This is generally true, but when it comes to fire protection the lock can be the weakest element. An intumescent lock kit can provide a door with a minimum of 30 minutes fire protection when fitted correctly by a professional installer. Hinges must also be fitted with intumescent pads; these seals are secured around the locks and hinges within the door to ensure complete fire resistance.

It’s not just about the doors though, many other important parts of a building require fire protection too; cladding, floors, walls and ceilings. All of these things have to be in place to ensure that a building has the best fire protection possible.

How well do you know your fire door hardware?

Topical news - news from other companies

Topical news - companies

Sign up to receive the free BUILDING DESIGN bulletin