Building Construction

Most buildings are vulnerable to the effects of man-made and natural disasters. The extent of the damage depends on the type of disaster and the construction of the building. Every type of structure will be affected - some buildings will collapse and others will be left with weakened floors and walls.

No matter what the scale of the damage, the techniques you use to rescue people remain the same.

Rescue workers should understand the patterns in which particular types of buildings collapse, both for their own safety and that of others. They must also keep untrained people from poking around in the rubble and debris. This may cause further collapse and harm trapped survivors.

Collapsed Buildings and Formation of Voids

Most un-reinforced buildings collapse into more or less predictable patterns. Often the collapsing structure forms what are called voids where people may live for some time. Rescue workers should know how to locate and search these voids.

When a floor or roof or other large section is supported on one side and collapses or sags on the other, it forms a lean-to-collapse.

The floors of a house or building are not built to carry tons of wreckage; as a result, when the weight of heavy loads, such as furniture and equipment, or rubble and debris, is concentrated near the centre of a floor, a V-type collapse may occur.

When load-bearing external walls are weakened, destroyed or sucked outwards, the bulk of the debris falls on the ground or street. The floors, roof and some of the internal walls are deprived of support and collapse in a heap, separated only by the furniture and such portions of the walls as remain. This is called a pancake collapse.

There may be voids formed by the furniture supporting the collapsed floors, and it is possible to crawl through these voids provided that such supports are not disturbed.

WARNING! Entering voids is extremely dangerous-You could be trapped or killed. Stay out of voids unless you are a trained rescue professional.