There is no such thing as a fire-proof material or fire-proof construction. All materials and buildings can be destroyed by fire of sufficient intensity and duration. Just as we require the services of an architect to plan a building. we need the services of fire protection concerning at the planning stage itself (NBC, Part-IV).
In the following portion of the text. the minimum standards which a planner should comply with and the fire-safety measures which are necessary in public interest are described. The fire-resistance of a building or its structural elements is expressed in hours against a specified test condition which is expressed in kcal/m2, and against a given intensity of fire.
There are four types of construction, according to fire-resistance considerations. namely type-I. type-2, type-3 and type-4. The fire resistance ratings for various types of construction for structural and non-structural members should be as shown.
.png "Fire-Resistance Rating of Structural Elements (in Hours)") |
| Fire-Resistance Rating of Structural Elements (in Hours) |
In this context. we define following terms :
Fire-separation is defined as the distance in meters, measured from any other building at the site, or from other site, or from the opposite side of a street or public space for the purpose of preventing the spread of fire.
Floor Area Ratio (FAR) is defined as the quotient obtained by dividing the total covered areal (plinth area) on all the floors by the area of the plot,
Total Covered Area of all Floors
FAR = ---------------------------------------------------
Plot Area
The Floor Area Ratio (FAR) for different occupancies will be restricted as per the type of construction.
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| FAR for Different Occupancies with Types of Construction |
High-Rise Buildings are buildings which are more than 15 metres in height, in which fire-fighting cannot be carried out from outside with the fire extinguishing appliances available with the fire-fighting services. In such buildings non-combustible materials shall be used for construction.
The use of flammable surface finishes on walls and ceilings affects the safety of the occupants of a building. Such finishes tend to spread the fire, even though the structural elicits Lilia be adequately fire-resistant. Finishing materials have been classified according to flame-spread ratings (NBC, Part-IV) and their use should be made as specified. The thickness of glazing shall not be less than 6.5 mm.
Every building meant for human occupancy shall be provided with exits sufficient to permit the escape of occupants in case of fire or other emergency. Exits should be clearly visible and the routes to reach an exit should be clearly marked.
Fire-shifty requirements for residential, educational, institutional, assembly, business, mercantile, industrial storage buildings have been stipulated in great detail in the National Building Code 'and they are to be incorporated in the design of a building.
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