How to Demolish a Building
If you are contemplating demolishing an older building to make way for new construction, you will have several options to consider for building demolition. The process depends upon factors such as the building location, structural materials, the purpose of the demolition, and disposal of the debris. In this blog post, we summarize the four most common methods for demolition.
Implosion is a violent bursting inward that allows for the sequential elimination of structural supports. We use enough explosives to eliminate the critical vertical structural supports. The placement of the explosives and the detonation timing in sequence is important. This allows the building to collapse by its own weight. Implosion demolitions typically take place in urban areas and are used primarily for very large structures.
Our crew uses a complete set of structural blueprints to analyze each main component of the building. Another critical step is the assessment completed by the blaster crew to identify additional areas that need to be blasted in addition to the areas targeted on the blueprint. The final step involves determining the type of explosives to use, where to place them, and timing the detonation.
High Arm Reach Building Demolition
High reach arm is another conventional method of demolition. The height threshold is over 20 meters. High arm reach uses a base machine, such as tank, engine, excavator, or counterweights. The demolition arm has three sections, or a telescopic boom and primary tool such as hammers, shears, or crushers.
High reach demolition machines can use different tools tailored to the specific demolition. This method is typically used on masonry, reinforced concrete, steel, or other mixed material structures. The following factors can make an impact on the process:
- Structure height
- Structure shape
- Site conditions
- Structure location
Demolition Method: Crane & Ball
One of the oldest and most popular ways to demolish a building is the ball and crane. The wrecking ball can weigh up to 13,500 pounds to demolish masonry and concrete structures. During the process, the ball is dropped onto or swung into the building to be demolished. The ball and crane is not appropriate for all demolitions and may be subject to these limitations:
- Additional work is needed to remove rebar in concrete buildings
- A skilled and experienced crane operator is a must
- Controlling the swing of the wrecking ball is crucial. Missing the target may overload or tip the crane.
- The size of the structure to be demolished is limited by crane size, working room, and proximity to power lines.
Also known as a strip-out, the selective demolition is very popular today. Both builders and demolition teams are keen on recycling and salvaging materials, which can have an attractive resale price or reduce construction costs by reuse and repurposing materials. Selective interior/exterior demolition that recycles brick, metals, wood, and concrete is being used increasingly with new structures to add character as well. This demolition process is not limited to removing walls, floors, ceilings, interior equipment, or exterior components. The primary purpose of selective demolition is to recover the maximum amount of reusable and recyclable material in a safe, cost-effective manner. Although it can be labor intensive, the labor costs can be offset by the resale or reuse of the materials.