Demolition means destruction, removal or breaking down of a structure by using pre-planned methods. The process of demolition involves five steps- surveying, removal of hazardous elements, preparation of plan and safety measures, to ensure a smooth and safe demolition process.
- Surveying- This involves the study of different areas of the construction and things surrounding the site. The two main types of surveys done are building surveying and structural surveying. Building surveying involves the inspection of construction material used, usage of the building, presence of hazardous materials, material made from toxic chemicals, flammable, explosive or radioactive materials, etc. The condition of drainage is also inspected in building surveying. Structural surveying involves the study of the method of construction of the building, condition of the basement or underground vaults and the condition of the building.
- Removal of hazardous materials- Hazardous materials like asbestos minerals, petroleum and radioactive metals are removed y specialized personals prior to the demolition.
- Preparation of demolition plan for structures- A detailed plan involving information about the location of the building, structural support systems of the building, a procedure for the demolition of the building, a plan for all the precautionary measure that should be taken, methods for handling the demolished building, and the time required is made.
- Safety measures are taken- Everyone on site during the demolition process such as the workers, engineers, site supervisors are briefed about the possible hazards in the site during the process of demolition. All flammable and hazardous materials are removed from the site and are taken care of. Suitable measure are taken to overcome the problems of dust, chemical exposure, heat stress, noise exposure, occupational diseases and sanitation facilities of workers. Have an a local electrician check that the power has been disconnected and made safe.
Demolition methods for buildings and other structures are of two main types, non-explosive demolition and explosive demolition.
- Non- explosive demolition method is the demolition of the structure which is done using different equipment, other than explosives. Some of the form of non-explosive demolition method are-
- Sledge hammers- Typically used for demolition of a single wall or column.
- Excavators and bulldozers- These are used for demolishing small buildings.
- Wrecking balls—higher buildings which cannot be demolished by bulldozers are demolished using wrecking balls. A crane with a wrecking ball attached to it is pulled and released onto the building leaving that part of the building demolished.
- High reach excavators are used for tall buildings which cannot be demolished using explosives.
- Explosive demolition methods include demolition of buildings using explosives. This explosion is mainly concentrated on structural support of the building such as the pillars or columns. The two types of explosive demolition methods are-
- Falling like a tree– In this method, the building is made to fall side-wards, if there is enough free space available.
- Falling into its own footprint- When there is no free space around the building, the explosives are set in the middle part of the building, causing the building to falls in the place it is standing.
- Asbestos removal is an important consideration when surveying a building prior to any work. Experienced building experts should be used to provide a report before any work is started. Companies like Roofers Brisbane are skilled and capable of this work.
- Pressure Cleaning and dust suppression to avoid contamination and damage to surrounding buildings, vehicles and structures. A survey of the local area should be undertaken to clean and remove any debris from the demolition.