Demolition

Demolition (also known as razing, cartage, and wrecking) is the science and engineering in safely and efficiently tearing down buildings and other artificial structures.

Demolition contrasts with deconstruction, which involves taking a building apart while carefully preserving valuable elements for reuse purposes.

The building is pulled down either manually or mechanically using large hydraulic equipment: elevated work platforms, cranes, excavators or bulldozers.

Newer methods may use rotational hydraulic shears and silenced rockbreakers attached to excavators to cut or break through wood, steel, and concrete.

[1] Before any demolition activities can take place, there are many steps that must be carried out beforehand, including performing asbestos abatement, removing hazardous or regulated materials, obtaining necessary permits, submitting necessary notifications, disconnecting utilities, rodent baiting and the development of site-specific safety and work plans.

The typical razing of a building is accomplished as follows: In some cases a crane with a wrecking ball is used to demolish the structure down to a certain manageable height.

They are typically equipped with "rakes" (thick pieces of steel that could be an I-beam or tube) that are used to ram building walls.

He cut an ingress at the base of the chimney—supporting the brickwork with wooden props—and then burning away the props so that the chimney fell, using no explosives and usually hand-operated power tools.

When a building fails to collapse completely the structure may be unstable, tilting at a dangerous angle, and filled with un-detonated but still primed explosives, making it difficult for workers to approach safely.

With proper planning this approach has resulted in landfill diversion rates that exceed 90% of an entire building and its contents in some cases.

[8] The development of plant and equipment has allowed for the easier segregation of demolition waste types on site and the reuse within the construction of the replacement building.

In the 2000s, teardowns by wealthy baby boomers replacing houses across America with outsized McMansions became so common that municipal building codes in many areas were revised, putting up more barriers to tearing down an existing homes.

"Canyon effect" is a term used to describe when smaller houses are surrounded by new, multi-story buildings with blank walls.