There are some factors that determine the different demolitions methods used. These include:
• The location of the building to be demolished
• The type of building materials used
• The purpose of the demolition
• The debris disposal method
There are 4 main demolition methods used:
This is a traditional demolition method that is dramatic and mostly used in big buildings in urban settings. This method involves using explosives to weaken the support structures of a building, which makes it collapse on itself.
Before placing the explosives, the demolition team studies the building’s blueprints very carefully to identify critical vertical support structures. For the implosion to have a complete effect, a blaster crew also assesses other parts of the building that need weakening. Demolition by implosion is very quick; a multi-storey office building will often collapse under 2 minutes.
Crane and ball
This is a traditional method of using brute force to bring down a building. A very heavy ball (weighing up to 13,500 pounds) is swung on to the building. This method is used on relatively small buildings, up to 3 storeys. Some crane operators will drop the ball on the building, while others will swing the ball on the walls. Crane and ball demolition has some limitations;
• The reach of the ball is limited
• A very skilled crane operator is needed
• It is not effective against reinforced concrete which necessitates additional deconstruction demolition
• The method produces makes a lot of noise and dust
• The disposal of the debris is not controlled
High reach arm method
This method uses a high arm that can reach heights of 20-50 meters. The arm is attached to a firm base, often an excavator or a bulldozer. The arm is telescopic to enable height adjustment. The active part of the arm carries steel cutters, crushers, hammers or shears. This method is usually limited by height, shape, and location of the building.
This method is also known as strip-out. It is the friendliest among demolition methods. This is because the building material from the demolished building can be recycled. This includes steel, bricks, and concrete. This method is usually used to demolish interior walls, ceilings, and floors.
The main goal of selective demolition is recovering as much usable building material as possible. This is very beneficial if the developer is the same doing the next development.
The main disadvantage of Selective development is that it is slow and labor intensive. It is also unsuitable for light framed buildings.
Western Environmental Solutions is a team of professional demolition experts that are conversant with all demolition methods.