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The Science Behind Demolishing a Building

As we expand the addition of new structures, we often require older buildings to be torn down to make space for newer buildings or because they are unsafe to use. These old buildings then need to be demolished. Demolition is the rock star in the construction industry with all its interesting aspects and the big show it delivers.
It may look like a big bang but demolition requires a precise process of finely controlled and planned methods to dismantle a building properly and safely. There is much more to demolishing a building than the big wrecking ball you see bashing through the walls. Demolition methods vary according to the building requirements but all methods require highly trained qualified experts who have to consider aspects such as debris, weather conditions, materials, mass, and physics.

Pre-demolition Process

There are many factors that a demolition expert has to take into account when planning and conducting the demolition of a building. Although a demolition project differs per building it typically includes the following:
1. Building survey: Experts analyze the surveying results to understand the different aspects of the building such as the building usage, materials, method of construction, building condition, drainage conditions, surrounding traffic conditions, building codes, and neighboring communities and water sources. These factors all assist in selecting the appropriate demolition method to be used.
2. Removal of hazardous materials: All hazardous material has to be taken out of the building before demolitions can begin. This includes asbestos minerals, radioactive substances, flammable materials, and petroleum contamination. Removal of these substances has to be done by trained specialists.
3. Demolition plan: A detailed plan is created by the experts that stipulate the equipment to be used, the exact process of demolition to be followed, and the volume of debris to be cleaned afterwards.
4. Safety measures: The demolition experts from the contracted industrial demolition company need to ensure that all permits have been obtained and all required local authority bodies have been informed. All site personnel such as workers, supervisors, operators, and engineers need to be advised of the process and resulting exposure to dust, noise and potential flammable material.

Building Demolition Types

There are several different demolition types each with their own specific strengths and uses. Not all demolitions involve an explosion and a cloud of dust. The different methods can range from high-impact blasts to non-explosive piece-by-piece removals and can include implosions, excavators, wrecking balls, bulldozers, and selective demolition. Each method also comes at different costing structures and requirements, which does impact the method selected a lot.

Building Implosion
Using the implosion method in demolition involves the use of explosives to blast through the main support of the building causing the building to collapse in on itself from the outside inwards. This controlled building demolition process reduces the volume occupied and concentrates the matter and energy making it suitable for demolishing large buildings in urban areas.
It requires specialized blaster certified experts and is the most dramatic and impressive demolition method. Due to the specialization required, this method only accounts for less than 1% of demolition methods used.

Excavator Demolition
Houses, offices and other smaller type buildings are mostly ripped apart by an excavator. A more industrial and heavy-duty machine such as a high reach excavator is used for taller buildings over 60 feet. Similar machines are used for stronger type buildings like those constructed from masonry, concrete, and steel. Various structures such as shears, crushers, and hydraulic hammers are attached to the excavator and these attachments do the actual dismantling of the building. These tool-equipped arms and structures pull the structure down from the top. This is a very controlled demolition method.

Wrecking Ball Demolition
The wrecking ball is the best-known method of demolition. This iconic symbol of demolition can weigh up to 12,000 pounds and is a massive ball of steel suspended from a crane. This gigantic ball and chain is literally swung and allowed to crash into the building thereby letting gravity give its massive weight force. There are a few methods to get the ball swinging and it can be hoisted up high or dragged back before being let go of, or using a crane can be whipped to get it moving. You have to be very careful and accurate when swinging the ball as it cannot be stopped once it is in motion. As the ball hits the building it can also veer off in any direction without any control.
This method is actually rarely used on construction sites as it causes a lot of dust, debris, and poses a safety risk. It is, however, a quick and cost-effective demolition method.

Selective Demolition
In these modern eco-conscious times, the selective demolition method is well-received. This method involves disassembling specific parts and sections of a building and keeping the structure intact, instead of demolishing the entire building in one go.
This method is a popular choice for building extensions, upgrades, and remodeling where you want to reuse and recycle as much as possible to minimize the environmental impact that demolition can have.

In the new and out with the old, the same applies to buildings and structures. When buildings have outlived their usefulness or become unsafe, they have to be demolished in the most efficient way that is safe and non-hazardous. An explosive demolition may seem exciting and thrilling to most, but it requires a lot of planning, precision and experience to do safely and successfully.