All buildings are susceptible to fire and this aspect needs to be considered during design since it impacts safety of human life. There has been enormous increase in buildings of all classifications consequent to socio-economic progress made in the country over the last two decades. In the 1990s came the DotCom revolution and stalwarts of Silicon Valley started creating new townships and work spaces in India. This demand encouraged construction of high rise buildings without clear anticipation of the associated infrastructure requirement of cities. The challenges and risks that high-rises face due to fire hazards have also increased manifold. These hazards have caused heavy losses to life and limb, throwing up challenges to planners, architects and fire protection services for evolving better and improved methods of design and fire protection in order to mitigate such losses. Over the years, fire safety in buildings has seen major improvements. The issue now being focused
on is the fire resistance and retarding properties of different types of façade materials as also the engineering aspects of assembly and fiment of façades over the base structures. Local codes are not clearly defied to ensure installation of façades as per international norms and conventions. This leads us to believe that dearth of awareness has created a forest of dense structures that may not be capable of ensuring safety of the structure and its occupants from fire hazards. Safety of life is the most important aspect that needs to be factored during design of buildings. Forensic studies have indicated that primary hazard to humans in a building fire is more from smoke and toxic gases. Nearly three-fourths of all building related fire deaths are from inhalation of the smoke and toxic gases produced in fire rather than from exposure to flame or heat. Many new materials used in building construction,like different kinds of plastic materials, are the worst culprits in production of highly toxic gases such as carbon monoxide, hydrogen cyanide, sulphur dioxide, hydrogen chloride, oxides of nitrogen, etc.
During a fire, it is the toxic gases that lead to asphyxiation of occupants. The build up of toxic gases can be rapid and could reach critical levels in quick time, providing little or no reaction time for evacuation. The lead time for build up of toxic gases would depend on the material used, combustion products, and physical and mental characteristics of the exposed individuals would govern endurance to withstand the adverse environments. Therefore, this short interval of time is very important, more precisely, the interval between fire occurrence and detection. Therefore, a lot of emphasis has been laid on fire detection systems and subsequently on aspects of thermal management and fire extinguishing techniques to be used in a building. The approach to dealing with a fire in buildings is encapsulated in the following box.
Key Mantra for Fire Safety
- Staged evacuation – Crowd management
- Slows the fire growth
- Minimize the smoke spread
- Automatic (Fire suppression)
- Fire service
- Structural Integrity
- Adequate Maintenance
While the approach for dealing with fire is quite standard and is known, methods followed in selection of building and façade material have been prescriptive. The client advises the façade contractor on the international specification or code for installation but does not have the expertise to inspect and comment on the installation. This could lead to aggravation of fire despite the correct material being used for façades.
Selection of standardized fire rated materials for façades is important, but we need to also ensure that correct practises of installation of façade materials and fire stops are also followed.