By Chris Emetoh
Ever wondered why there have been increase in the number of building collapse in Nigeria recently?
Many a number of reasons are attributable to this, some of which may be as a result of structural failure or natural disasters like an earthquake, hurricane, flooding, landslide, tornado or a mudslide, acts of terrorism may not also be overlooked in some cases though.
Nigeria has suffered its share of building collapse in the past with several cases of buildings collapsing and killing scores of people. On July 24, 2020 A three-storey building still under construction collapsed around Dawaki, a suburb within Abuja Municipal Area Council (AMAC) of the Federal Capital Territory (FCT). December 10, 2016, Nigeria was hit by a tragedy when a church collapsed in Uyo, the capital of Akwa Ibom; killing over 200 people.
The 2014 Synagogue Church building collapse in Lagos, hit Nigeria with at least 116 deaths, The 2019 Lagos School collapse in Lagos, Nigeria causing 20 deaths and over 60 injured.
On September 22, 2015, a building collapsed in the Lekki axis of Lagos State. In May 2016, a four-storey shopping complex in Ogun State, which left many dead
In October 2015, a three-storey building collapsed in Lagos. Sadly, there has been an increase in the number of collapsed buildings in Nigeria in the last 10 years.
Building collapse is a failure in a structure due to its inability to serve the purpose for which it was built.
These cases are more in developing cities as a result of urbanization and the need to provide shelter for the influx of people trooping into the cities every day. This has, in fact, led to an increase in ‘building contractors’ of zero training and doubtful competences. A particular research on the the fatality rate in the reported cases of building collapse from 2000 to 2020 observed not less than 300 deaths and casualties in Nigeria’s major cities alone with an enormous loss of investment.
The increasing number of cases mandates the need for a wakeup call to all stakeholders in the industry. Failure of a structure is not just a result of ultimate collapse but when any part of the structure or the whole structure becomes unfit for use for the intended loadings for which it was designed to carry.
Failure of a structure then could be any of the three scenarios: Materials Science and Engineering, Serviceability limit state failure occurs when it becomes unserviceable by undergoing excessive deflection and cracking;. Ultimate limit state failure happens when it fails by overturning, ultimate collapse, or wobbling of the columns. The structure is said to have failed in Ultimate limit state.
Durability failure has to do with the weakening of the components beyond reparable limits. The traditional materials used in previous centuries made buckling not a major structural problem and multi-storey structures were uncommon during these ages. There is a tendency to make sure important structures do not fail by using materials generously making many of the roman structures survived till date
The standard of living has increased over the centuries bringing with it huge strides in technological advancements. Today, there are better procedures, more durable materials, better construction machinery and more advanced knowledge on construction. However, with all the advances in technology, there are still cases of collapse in countries of the world, though more prevalent in developing countries like Nigeria. Collapse in the developed countries is majorly due to natural causes or man-made causes like bombings like the world trade centre. However, collapse in developing countries are usually due to poor quality or substandard materials, poor supervision, non-adherence to standards and regulations, unqualified professional, overloading, no geotechnical/sub-soil investigation, poor construction procedure, illegal approval, wrong demolition process, lack of maintenance and several other factors.
According to the General Manager, Lagos State Building Control Agency, Sola Adeigbe, a total of 1,104 buildings were sealed from Between June and October 2016 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 state know if such buildings can be renovated or re-engineered.
In cases where building are detected to have a defect, building owners are asked to take the test before further actions are taken by the state.
As part of our commitment to ensuring the safety of homeowners as well as those who live or work in properties in Nigeria, we have compiled a list of 7 warning signs that should not be taken for granted.
The moment you notice any of the warning signs we will discuss in this article, immediately evacuate the building and make it a point of duty to notify your nearest Local Council Development Area (LCDA)
Major cracks in the 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, you must understand that this is a structural defect that could end very badly.
Uneven spaces and sloping floors are not to be taken lightly. For instance, take a look at the house from the street. 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 used: 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 and fissures 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 your 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 the house you live in begins to make creaking and popping sounds, you should be very worried. In September 2016, a resident heard creaking sounds on the 7th floor of a building which 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.
If you ever find yourself hearing 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
There is usually one way mould and rot are caused – Water got to a part of the house that should not be wet. 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. Your house construction should allow for this.
If this does not happen, it could result in clay lump walls collapsing.
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.
A building does not suddenly collapse in one night without any warning sign. The signs are usually there to be seen. One of the biggest problems with these signs is that if neglected, they make the collapse of the building inevitable. In essence, early warning signs should not be handled with levity.