Building demolition is an important element that is regularly encountered during the construction and renovation of buildings. Old structures are demolished, to build new buildings in their place.
Following are the general procedures for the Demolition of a Building.
(1) Site Inspection.
- The type of building will have to ascertain whether it is a tiled roof or with an RCC Roofing.
- The size of the building or the area of the building has to be obtained before demolition.
- Roof structure, wooden Doors and windows & wooden ceilings will have to be inspected thoroughly to calculate the value of useful materials. This is very essential. Sometimes the client will have to bear any costs for the demolition works.
(2) Methods of Demolition.
- If the building is so small, it can be easily demolished manually by using a sledgehammer, Crowbars, Drills etc.
- If the building is a large one or up to 3-storeyed building, could be demolished by using a Jackhammer or Drill and cutting Blades etc. For this purpose, very skilled labourers are required.
- The demolition of very big buildings or skyscrapers is done after detailed studies and investigations. Sometimes it may take months, but actual demolition takes only a few seconds. Such buildings are demolished by using Dynamites and Detonators.
In some cases, even plastic explosives are used. These jobs are done by very big companies having explosive experts and technicians.
Costs of Demolition of Building
For the Demolition of normal and common buildings, the following are the approximate rates.
- Brick wall up to 20 to 22 cm thick. Rs 20/ sft.
- RCC Sunshade and Lintel. Rs 45/ RFT.
- RCC slabs of 10 to 12 CM thick. Rs.30/ sft.
- RCC Beams of size up to 20 * 45 cm Rs.90/ RFT.
- Brick wall Blade cutting up to 22 cm thick Rs 90/RFT.
- RCC Slabs Blade cutting up to 12 cm thick Rs. 110/RFT
Demolition of Foundations.
In certain cases, demolition of the foundation also becomes necessary for the construction of a new foundation for the proposed building. The following types of foundations used to be demolished.
(a) Masonry Foundation
The Foundation for most of the old residential is with Random Rubble, Laterite Stone, Bricks,& Pcc blocks. For the Demolition of these foundations, Earth’s work excavation also will have to take into consideration.
The total approximate cost will be Rs.2350/ cum.
(b) RCC Foundation.
Mainly with an RCC mat on the bottom, Raft and Plinth beams, RCC Columns and footings etc. The approximate rate including earthwork excavation will be about Rs.4000/ cum.
Precautions are to be taken before any Demolition works can begin.
- Permission shall be taken from the Electricity Authorities for consuming Electricity for Demolition purposes.
- All necessary precautions are to be taken for the buildings not to be collapsed during the demolition process. Roof Slabs, Beams, and Arches will be properly supported with steel props, Across spans etc. with sufficient spacings.
- Before commencing a Vertical blade cutting of a masonry wall or RCC slabs, which may be necessary for a renovation of the building, the cutting place should be properly marked from both sides of the cutting surface to ensure a straight cutting.