Building collapse has dealt great blows to Nigerians across all sectors, affecting public buildings, private buildings, government buildings and even religious buildings. Aside the losses recorded in terms of human lives, properties and other things, owners of such buildings will also have to engage labourers to help evacuate the debris and prepare the place for another project.
The most worrisome is that after any incident of building collapse, authorities will reel out glowing precautionary measures to be taken to avoid future occurrences only to soft-pedal in terms of implementation until another incident is recorded.
Building collapse in Nigeria will not stop until the country changes its approach to issues. Building construction is like a sick person and if you refer a sick person to a carpenter for treatment, it is either the person will die or continue to be sick. So buildings will continue to collapse if the nation continues giving its construction contracts to non-professionals. Until building construction is given to engineering professionals, Nigeria will continue to grapple with building collapse and its attendant effects.
The soil in these areas is sandy and loose, so it is not strong or compacted soil, hence, the need for building construction professionals is usually high here. For most of these buildings, they dig long and strong piles foundation; however, few still collapse. Most three- or four-storey buildings in Lagos Island are at best good for 15 years. Remember the lands are not strong and people build on them using templates used for better and more compacted lands. So what causes the collapse of these buildings.
This issue has been overflogged both in print and electronic media but the same problem still persists. There is also the problem of egghead professionals who believe they know all and are not ready to take advice from a colleague. There are known cases like that, that have turned awry. For instance, some of the big buildings collapsing in the Lagos business district were handled by professionals.
The issue contractors trying to make gains at the expense and lives of users of the buildings is another problem that has to be tackled. There should be a check from policy makers to ensure specification is thoroughly followed by contractors.
As insignificant as human weight may seem, the moving up and down of live loads and dead loads contributes, over time, in no small measure in wearing down a building. It may take a long time though, but houses also expire and in the case of the types of buildings we have in Nigeria, their lifespan is shorter than others in the civilised world.
The foundation is the most important part of a building. Unfortunately, a lot of people are not giving adequate monitoring to this and it is causing more problem. A registered Structural Engineer is very important to you if you are planning on building a strong and solid multi-storey building.
Many do not know that buildings also have their lifespan. Most of the buildings in Lagos Mainland have lasted for 25 years and above, despite that they were built on shallow foundations and with low quality materials. If you use low quality material thinking you’ll cut cost, then be prepared to park out of that building very soon.
The Nigerian Institute of Architects (NIA), after reviewing the situation, blamed the incessant cases of collapsed buildings in the country on the high cost of building materials and the use of substandard materials in building construction. They called for the involvement of architects and other professionals in the building industry in the course of executing capital projects in the country. While various experts groups’ investigations are still underway into the cause of the issue, they suggest some possible common problems that include but not limited to the following:
•The foundations are too weak
Adequate foundations are costly and could cost up to half the price of a building. According to a Professor of Civil Engineering, Anthony Ede, at Covenant University in Ota, Nigeria, two things should be considered when building the foundations – the solidity of the soil and the heaviness of the building and its contents. He noted that in the commercial capital of Nigeria, Lagos, the swampy ground requires strong foundations, far stronger than the ones on solid ground. He observed that developers save money that should be spent on foundations when building on the city’s swampy ground and many buildings have collapsed in Lagos as a result. He added that even on solid ground, foundations need to be strong enough for the load.
•Building materials may not be quality ones
A building expert from the African Organisation for Standardisation, Mr. Hermogene Nsengimana, whose organisation met last month in Nairobi to discuss why so many African buildings collapse, blamed materials not strong enough to withhold the load for the incident. He suggests there is a market for counterfeit materials, going as far as saying that sometimes scrap metal is used instead of steel. When a six-storey building in Uganda’s capital, Kampala, collapsed in April 2017, the director of the city authority suggested it had been constructed with counterfeit materials. Nsengimana said there are even cases of counterfeiters faking authentication certificates but stated that contractors also knowingly use the incorrect materials to cut costs.
So they may use concrete intended to bear the load of a one-storey building in a four-storey building.
•Workers make mistakes
Even when workers are given the right materials to make the concrete, they mix them incorrectly. This results in concrete, which is not of the sufficient strength to hold the load. Developers are also fond of cutting costs by employing unskilled workers who are cheaper than trained builders. Research also shows that majority of workers misunderstand the mixing ratios of concrete. People mostly use wheelbarrows instead of measuring gauges to measure cement. By making assumptions with measurements, you are bound to make mistakes.
• Vibration in any surface
When a building is mounted on a porous surface and heavy machines are made to work there, the building is bound to collapse. This goes a long way to describe why vibrations around any building is capable of bringing accelerated aging and structural defects to projects seen to be solidly constructed.
Today, a lot of structural defects are caused to buildings that the authorities that sanction such activities fail to measure the extent of such damages. One among the measures to take to safeguard foundations of buildings is not to allow heavy duty machines do the excavation job around them. This, if allowed, helps in shaking the foundations of the buildings around that area thereby fast-forwarding the speed with which they age and defect.
Reports after reports have documented the fragility state of many buildings and called for the urgent attention because of their critical disrepair state due to aging and degradation. Delaying prompt actions implies a high risk of catastrophic failures and probable human loss. Retrofitting and rehabilitation provide remedies to reduce the vulnerability of those systems. Almost always, data about the structural health of the components in a building being considered for retrofitting or rehabilitation is required for any engineering calculations. Nonetheless, the true structural condition is challenging to the practitioners in many projects because of the complexity of geometry, framing systems, detailing of connections, workmanship, etc.