Two building collapses have received a great deal of media coverage thus far in 2013: the building collapse in Thane, Mumbai and Savar, Bangladesh. Whereas 74 people lost their lives in the Thane building collapse, the death toll was more than 700 in the Savar building collapse.
In the South Asian cities that are witnessing rapid urbanization, building collapses are a common phenomenon, but these tragedies seem to mostly occur in small buildings belonging to low income and informal and semi-formal neighborhoods. In fact, it is quite possible that the total toll caused by such collapses could be higher compared to the large-scale ones that happen occasionally.
These collapses do not necessarily occur because the buildings are illegally constructed. Gaps in the system lead to poor quality of construction. Further, multi-floor structures are constructed by untrained workers without proper engineering knowledge.
Often, generic reasons such as use of substandard materials and poor construction are attributed to building collapses without conducting any proper investigations. The aim of this article is to provide some information as to how you can spot bad construction.
#1: Constructing buildings, especially high-rise buildings, without performing proper soil analysis can cause cracks on the structure as well as on the outside pavement.
Types of foundation problems can include windows and doors that make noise, jam or separate from frames, cracks that appear near the corners of windows and doors as well as at wall joints, cracks in basement that continue to widen or cause water seepage and leaky roofs.
#2: The use of defective building material can cause construction defects. For example, water leakage caused by defective material can weaken the structure.
Defects in construction and use of bad construction material can be spotted by looking for presence of moisture, mold and mildew in buildings.
#3: The vertical or horizontal cracks on plastered walls indicate shrinkage and drying and are normal. Cracks that are jagged, resemble stair steps and are at 45 degrees generally point to settling issues and structural movement.
These cracks are usually harmless, but can be serious sometimes. A crack that is less than 1/8th of an inch width is usually caused because of stress and is considered to be harmless. However, a crack that is 1/4th of inch or more wide is more serious.
In the case of concrete walls, vertical as well as diagonal cracks typically signify foundation movement. If the vertical crack widens at the bottom or top, it may be because of settling or gradual heaving. Stair-step cracks also indicate heaving. Horizontal cracks signify design defects or build up of pressure behind the wall. Horizontal cracks can cause serious problems. Design aspects are compromised and people who do not have adequate technical knowledge related to construction of buildings are frequently entrusted with the multi-floor building projects.
Finally, the rising cost of land and building materials drives people, especially those living on low incomes, to seek cheaper options. In Indian cities, this invariably means being at the mercy of fly-by-night developers with no reputations to protect. This is regrettable, because many reputed developers have projects in various price-bands. In other words, a lower price does not have to mean dangerously low construction quality.