Fire classification of buildings
In the national regulations buildings are normally divided
into 3 - 5 different fire classes based on the number of
floors, type of use, size and fire load. Demands on
building materials and constructions vary between the
building classes.
Fire classification of constructions: Fire resistance (compartmentalization)
Inside the building different spaces are divided into fire compartments to prevent fire spread for a certain time. Fire compartments should restrain the spread of fire inside and outside the building and make the firefighters' work easier in case of fire.
National building regulations are usually giving instructions for compartmentalization but generally compartments are formed by the different floors, different use of spaces and the size of the area.
In the compartments specific building structures are required to provide minimum periods of fire resistance expressed in minutes.
R = load-bearing capacity
E = Integrity. A separating element must resist collapse,
the occurrence of holes, gaps or fissures through which
flames and hot gases could pass and sustained flaming
on the unexposed face.
I = Insulation capacity. A separating element must restrict
the temperature rise of the unexposed face to below
specified levels.
The fire classes R, E and I are followed by a time
expressed in minutes indicating how long the structure shall resist fire, e.g. EI 60 or REI 60.
If fire occurs, the most important thing is to be able
to evacuate the facilities as fast as possible and
thus save human lives. The time to escape is depending on the building materials and their fire properties. Local fire regulations clearly state the requirements on materials in terms of reaction to fire.
Fire classification of materials: Reaction to fire (fire growth)
According to local fire regulations materials used in building components shall |
