The past 4 years have seen about 54 buildings get collapsed all over the country according to the Federal Ministry of Power, Works and Housing. Whenever a building collapses in Nigeria, either old, under construction or under repair, it sends waves of tremors down the minds of everyone.
We begin to wonder if we’re the next to be in the wrong building at the wrong time. Statistically, there is no reason to be panicky as the rate of collapse of building to surviving buildings is negligible, but you cannot remain negligent, as it can prove fatal and devastating for you and your entire family.
Hence this is the right time to know and understand the reasons for collapse of building and to take precautionary and remedial measures if at all it is applicable to you. Here we give a series of reasons for collapse of buildings in the country.
IDENTIFIED CAUSES OF BUILDING COLLAPSE
Research, thorough investigations and media reports have identified the following main causes of building collapse in the country.
1. Defects in Design and Drawings
The sound architectural as well as structural design is very crucial for the most excellent performance and maintenance of buildings. Many times, it is observed that the building collapses due to the error in design. The improper design decision will lower the quality of construction and lead to defects during the service life of the building. Defective Architectural and Engineering drawing may result if architects fail to do or insist on the carrying out of feasibility studies, soil and site investigation which are the bases for design of adequate architectural and structural drawings. Others include poor design details, low quality materials and works specifications. Engineers (structure and civil) may contribute if they fail to insist on carrying out essential soil test, foundation design. Errors, omissions and inaccurate data from professionals may lead to problems if not detected on time.
2. Use of Inferior Materials
Ideally 1 bag of cement is used to mold 40-45 numbers of 225mm (9ins.) blocks. Without adequate supervision, contractors can engage in sharp practices to produce more blocks with 1 bag of cement in order to misdirect funds. This will result to the production of inferior blocks. Cement-Sand ratio is better obtained in weight and not in volume. It is necessary that steel reinforcement bars undergo tensile strength tests to determine its standard strength. The country and the higher institutions cannot boast of adequate number of laboratories to carry out these tests including concrete cube tests for concrete and water quality. The use of substandard materials and untested construction methods is a major contributor to structural failures of buildings.
3. Faulty Execution and Inadequate Supervision
The execution errors by the engineer onsite contractor, wrong decisions and supervision lapses of construction head, the stupidity of workers, and the lack of knowledge of standard construction materials and construction processes lead to the low quality of construction work. These deficiencies reduce the load-bearing capacity of the building in terms of strength and also reduce life and durability of the building, which may result in the collapse of building fully or partially due to lack of integrity and homogeneity.
4. Non-Adherence to approved building plans
This comes in form of illegal alteration to approved drawings. Sometimes, a building originally specified to undergo in-situ concreting is changed to pre-cast methods because the expatriate contractor tends to prefabricate the components overseas and ship to Nigeria. This practice if not properly controlled could spell danger years after the buildings are in use. Absence of proper site and soil investigation: The avoidance of this to determine suitability of the terrain and soil’s bearing capacity, which influences foundation types spells danger.
5. Engagement of inexperienced personnel to take charge of construction works
Sometimes firms resort to use unqualified staff to act as principals on construction sites in order to save cost. The consequence of this practice is that the unqualified staff may not be competent enough to detect fraudulent practices of smart contractors. This may lead to covering up of shoddy or defective works.
Do the right thing when building, the consequences are dire, there is no need to compromise.