Enclosure fires

smoke gases in the compartment, but the actual fi re is very
easy to extinguish. This situation is very common with house
fi res in Sweden.
In the case of scenario 2 (the fi re grows – see Figure 9), we
need to give a bit more thought. Also, as it is interesting to see
what happens when the fi re spreads further, in the next section
we will look at how and in what way the fi re will be able
to spread during the initial phase.
The fuel’s arrangement in the compartment is crucial to
the fi re’s continuing behaviour. Porous and wood-based materials
in furnishings contribute to the fi re’s rapid development.
Plastics sometimes cause fi res to spread very quickly due to the
fact that they drip to form pools of fi re on the fl oor.
We will now look at how the material ignites and fl ames
spread with objects. It is important to understand these processes
in order to be able to learn how a fi re’s intensity increases.
Figure 8. The fi re does
not spread.
Figure 7. The initial
cause of a fi re can be, for
instance, a desk lamp or
a cigarette which ignites
a sofa.
Figure 9. The initial fi re in the sofa grows
bigger. The fi re’s area increases.
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