Fire Safety in Buildings: A Critical Concern
In the discussion of building safety, fire, in comparison to thermal and acoustic insulation (which are related to costs and mental well-being), holds immense importance. Similar to earthquakes, fire is directly linked to human lives and property, especially in steel structures.
We have national regulations concerning fire safety, including Topic 3 of the National Building Regulations and Publication 682 of the Housing Research Center, which provide specific requirements.
How Does a Fire Start and Spread?
As you know, the “Fire Triangle” consists of three sides, requiring three essential elements to ignite and sustain a fire: Oxygen, Heat, and Fuel. If any of these three elements is removed, the spread of the fire will be hindered, and without all three simultaneously present, igniting a fire would be impossible.
Oxygen
The presence of oxygen is essential for combustion to occur; it is this factor that allows fire to persist. Therefore, the most common method for extinguishing or controlling a fire is to remove oxygen from the fire or the fire triangle, commonly referred to as “smothering the fire.” When we throw soil or water on a fire, in addition to reducing its heat, we also prevent oxygen from reaching it.
Heat
When the fuel material is given the necessary heat, assuming oxygen is present, it ignites and fire breaks out. Of course, oxygen is always present alongside the fuel, but all fire-starting techniques require an initial source of heat.
Fuel
Fuel is the material to which heat is applied to start a fire. Once a fire occurs, the heat from the flames sustains the fire, provided more fuel is available. By removing the fuel, there will be no fire.
As you can see in the figure below, the behavior of materials and components is crucial for fire initiation. For a complete fire, where all three conditions of the fire triangle are met, the behavior of assemblies and structures becomes paramount. At this stage, the behavior of individual materials no longer holds significance; instead, it is the performance of the assemblies and structures that matters. How long a structure can resist fire, prevent the passage of smoke and flames, avoid deformation, and similar factors will determine if there is enough time for people affected by the fire to evacuate from designated fire zones (areas provided for entry and exit).
Here’s an illustration of the fire triangle:
And here’s an image depicting the stages of a building fire:
