Demolition is an act of destroying or wrecking the property. It is the opposite of construction. Which building has to be destroyed and which method employed depends on the structure and neighborhood of that building. It is generally considered in old buildings for safety reasons. There are various ways of demolishing the property. Demolition can be both complete and partial. In complete demolition whole of the building is destroyed, while in partial demolition only a part of the building is destroyed.
Demolition can be carried out by various methods; however the choosing the safest and simplest method is the general rule. It can be easily accomplished for the small two to three storied buildings for example houses. In this case laborers can demolish the building manually with their traditional equipment .or other mechanical equipment like cranes, excavators or bulldozers. Generally both mechanical and manual methods are used simultaneously. For larger buildings we need different equipment like wrecking ball, a heavy weight on a cable that is swung by a crane into the side of the buildings. Wrecking balls are not an efficient method that is use for destroying the building. They are mostly used to destroy masonry. Newer methods are now in vogue which includes rotational hydraulic shears and silenced rock-breakers attached to excavators to cut or break through wood, steel, and concrete. Whenever there is danger of fire we use shears. Another type of demolition is called undermining. In which the building can be brought down quickly in the desired direction. This process causes the collapse of the building by removing important supporting structures usually near the base.
Demolition can also be classified as explosive and non - explosive. Explosive demolition is an efficient way of destroying the buildings. This method is employed for large buildings. We use TNT, nitroglycerine C4 and detonating cord. It has the advantage of efficiency and cost effectiveness. But it has a lot of hazards.