-By Danlami Nasir Isah
There are many reasons that have been attributed to building collapse. These reasons range from natural disasters, human error, flooding to mudslide, explosion among others.
Already, Nigeria has suffered its share of building collapse in the past with several cases of buildings collapsing and killing scores of people, a situation which has made experts call for purge of quacks in the profession.
Statistics has shown that Lagos is the state with highest cases of building collapse especially storey buildings.
According to the General Manager, Lagos State Building Control Agency, Sola Adeigbe, over 1,000 buildings were sealed from June 2016 till date across Lagos State as a result of defective or illegal construction.
The fact remains that buildings do not just collapse. There are always warning signs. In many cases, the building control agency of several states in Nigeria carry out a non-destructive integrity test.
This test according to real estate professionals is to ascertain the structural stability of the building. This helps the authorities know if such buildings can be renovated or re-engineered.
In cases where buildings are detected to have a defect, building owners are advised to take the test before further actions are taken by the state.
Consequently, the public has been advised by experts on key seven signs to notice of a building that is about collapsing. They include but not limited to the following:
- MAJOR CRACKS ON WALL
Thermal movement remains one of the most potent causes of cracks to appear in the walls of buildings. If overlooked, this could eventually lead to the collapse of the building.
A crack in the wall of a building is a natural sign that the structure is unable to accommodate the movement or load to which it is subjected. When cracks appear in the walls of a building, it is either a structural crack or a non-structural crack.
While structural cracks appear as a result of incorrect design, faulty construction or overloading, non-structural cracks appear due to internally induced stress on the materials used in constructing a building. - GAPS BETWEEN FLOORS
When there are gaps between the walls and floors of a building, people must understand that it is a structural defect that could end very badly.
Uneven spaces and sloping floors are not to be taken lightly. For instance, experts say that one should take a look at the house from the street and ask the question: Is the front entrance straight? For contemporary homes, sloping floors are a really bad sign. - DETERIORATING SUPPORT STRUCTURE
Deterioration can result due to different reasons including;
Substandard Materials: As building components fail, they can directly impact on the exterior walls. The collapse of interior floors can push against masonry exterior walls and this eventually paves the way for the collapse of buildings.
Tears in foundation structures: This can also happen when fissures appear in welds of steel during construction or over time.
A building is likely to undergo progressive collapse when a primary structural element fails, resulting in the failure of adjoining structural elements, which in turn, causes further structural failure culminating in a building collapse.
Deformed Siding: Siding is what protects building from the moisture and the elements. It can be found on the inside and outside the walls of the buildings that are well constructed. When not kept in good condition, it can deteriorate and result in weakening of foundational structures; something that often leads to building collapse. - CREAKING AND POPPING SOUNDS
When a house begins to make creaking and popping sounds, one is expected to be worried. It was reported in a part of Lagos in September 2016, that a resident in Lagos heard creaking sounds on the 7th floor of a building which was ignored and the building eventually collapsed.
When a house creaks, what is happening is that the metal parts contract much more than the wood does. As a result, the nails, pipes and air ducts rub against the wood.
Also, the wood rubs and grinds against other wooden parts of the structure, which creates the creaking sounds.
It is advised that if the public hears weird sounds and cracks especially during strong winds, it’s a sign you should pay attention to. - MOULD AND WATER STAINS ON WALLS AND COLLAPSING CEILINGS
It is said that there is usually one way mould and rot are caused which is when water gets to a part of the house that should not be wet.
Sometimes professionals prefer to call this ‘moisture penetration.’
When there is an excess of moisture that can’t escape within the structure of a house, it is called a damp.
The natural tendency of moisture is to spread out from wet parts of a house to the dry areas. The moisture would also move downwards with the under the influence of gravity.
If this does not happen, it could result in clay lump walls collapsing.
Also, indiscriminate collapse of ceilings suggest early sign that a building collapse is almost imminent.
MOVING HOUSE
One of the most dangerous warnings of an impending collapse is when the house is moving. The movement here does not refer to the way a human would move. Rather, this means that over a period of time, certain parts of the house have shifted from their original position as a result of foundation problems.
Technically, when the foundation of the building shifts, it sets into motion, a disturbing number of serious events throughout the house, which forces the house to move.
Subsequently, building experts have warned that a building does not suddenly collapse in one night without any warning sign as there are always signs that are usually there to be seen.
However, they say that one of the biggest problems with these signs is that if neglected, they make the collapse of the building inevitable, as such they advise that early warning signs should not be handled with levity.