Suomeksi
The National Building Code of Finland’s type approval guidelines include structural requirements, which specify that fire doors must have a fire resistance time matching that of a fire wall. The fire door’s fire resistance properties are indicated using the symbol EI (integrity and insulation), followed by the fire resistance period expressed in minutes, for example 240.
Only closed doors contain fires
A major fire broke out in a paper products export terminal in June 2009. Within a few hours, the conflagration had spread throughout the 5,000 square-metre warehouse made of sheet metal, consuming the paper stored within and almost razing the structure to the ground. The fire services were alerted by the automatic fire system. When they arrived, the entire warehouse had succumbed to the blaze, which began during a staff coffee break.
A video surveillance tape examined afterwards showed that the automatic fire doors on site had closed. Within minutes of their closure, the warehouse was choked with smoke, while debris cascaded from the ceiling as the fire raged through the building via the ceiling structures. The employees arrived to find the fire door of a railway pit ajar, due to rail cars awaiting loading. Ingeniously, they used a wheel loader in the warehouse area to haul the rail cars out of the warehouse, enabling the fire door to close and the fire
to be contained. A correctly constructed fire wall and properly functioning fire doors prevented the fire from spreading to the adjacent warehouse and further to the nearby tarpaulin hall.
Two types of doors, two typical mistakes
Fire doors, which form part of fire compartments, are either self-closing and bolting or equipped with devices, which will close them if fire breaks out. Furthermore, such doors should meet the requirements set for fire resistance time.
A clearance area of at least 1.5 metres must be maintained in front of a fire door. Under no circumstances should combustible materials be kept directly against such a door.
Two common errors are committed with respect to fire walls forming fire compartments, preventing the doors from fulfilling their purpose:
- Fire doors are wedged open with wooden, plastic or metal wedges. A fire door designed to be self-closing will not function if wedged open. Neither should any items be left in front of such doors, which might prevent them from closing automatically. With regrettable frequency, a fire has turned into a conflagration after spreading from one fire compartment to another through fire doors, which have been wedged open.
- Another common mistake is to prevent the self-bolting of the doors in order to make them easier to use. If a fire occurs, the door will then open due to the overpressure caused by the fire, allowing the blaze to spread freely between fire compartments. A self-bolting door can be used without a key, since it relies on a latching mechanism.
Mark them clearly
Any door, which forms part of a fire compartment must always be in working order. The door plates and hinge side of the door frame must be equipped with a type approval plate made of metal. To increase awareness of the importance of fire doors, they should be clearly marked and bear an appropriate sign, such as “Automatic fire door - Do not prevent from closing”.
The functioning of fire doors should be tested on a monthly basis, during every internal fire inspection.
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