For they are out to reduce things to a rubble only to build anew. Demolition thus has become an art that has its own science as well as lends itself to business.

The City’s in a transitory phase. A host of infrastructure projects are giving the City a new makeover. Old buildings are giving in to depredations of time and making way to new ones. Demolishing buildings and other old structures is big business now.

Pulling down a building costs anywhere between Rs one lakh and to Rs 20 lakh. The cost of demolishing a building is primarily based on the built up area and the age of the structure. The demolishers also make good money by salvaging material such as windows, door and steel frames from the buildings. Barring construction material like bricks and mortar, everything else serves one or the other purpose. Scrap like steel sold in bulk brings in money.

With the amount of demolition work on in the City, there’s fierce competition as well. Technology employed provides one demolisher the edge over the other. The technology employed depends on the location of the building. The work is all hi tech on busy stretches and low tech in isolated areas.

Apex Demolishing Company who demolished the 1910 Kannan building on M G Road, used a mix of old and new technology to pull down the structure. First a certain chemical mixer was sprayed on the walls of the building to loosen the mortar. This mixer was left overnight.

“Once the chemical sunk in, demolishing became easier because the chemical mixed with water expanded the concrete. We then used mechanical breakers,” says Munzur, owner of Apex demolishers.

Apex demolishers use the Hitachi Paclain JCP in all in their operations. Steel scrap obtained from slabs and beams are sold off to sub-dealers. While each brick is sold for 50 paise, each tonne will cost nothing less than Rs 50,000.
Binyas Contech Pvt Ltd, another major demolishing firm in the City, is perhaps one of those few technologically sound demolishers.

The firm studies the structures in depth before evolving a strategy to pull it down.

Apart from demolitions, Binyas also performs life-enhancing surgery on structures. Concrete frames and walls are reinforced using electrical chipping, core drilling, floor sawing, wall sawing, wire sawing, splitters and crushers.

The strengthening package involves replacement, corrosion repairs, alterations and renovations.

Niranjan C B, executive coordinator, Bangalore operations says the cost of demolishing a building varies with the technology used. “It’s more expensive to demolish buildings partially because it calls for use of technology in such a way that the other part of the structure is safe,” he says and adds that it’s much easier to demolish the entire building.

Binyas also specialise in strengthening old structures. According to Niranjan, strengthening any structure means one is adding an extra 20 years to the life of the structure.

Some of the features that are unique to hi-tech demolishers are that they resort to vibration-free, low-noise diamond cutting, sawing and slicing of reinforced cement concrete with tools like Hydrostress, Diamond Etoart, HILTI, Cedina equipment imported from Switzerland, the US and Austria. Besides electrical chippers, thermal lance technology is used for thermal cutting.

Demolishers such as Bharat Old Building Demolition Contractors still use bull dozers and manual labour to pull down buildings in the City. Their annual earnings go up to Rs 10 lakh.