Evaluation of Concrete Block Wall Cracks in Residential Buildings in Kogi State

Wall cracking is one of the most frequently reported building defects in residential construction in Kogi State, North Central Nigeria, and its causes range from minor aesthetic issues to indicators of serious structural distress. This study evaluated the types, patterns, and causes of concrete block wall cracks in 70 residential buildings across Lokoja, Okene, and Idah Local Government Areas of Kogi State. Physical inspection was conducted using a structured crack documentation protocol recording crack type (vertical, horizontal, diagonal, random), width, length, location, and pattern. Crack patterns were analysed using established diagnostic classification systems to identify probable causes. Building professionals (n = 35) were interviewed on observed crack causes from their professional experience. Results showed that diagonal cracks at wall openings were the most prevalent type, present in 58% of inspected buildings. Random shrinkage cracking was recorded in 43% of buildings. Structural settlement cracks were observed in 19% of buildings, all of which were located on filled or expansive soils. Crack width analysis showed that 31% of observed cracks exceeded the structural concern threshold of 0.3 mm. The primary causal factors identified were differential foundation settlement (32%), thermal and moisture movement without adequate provision (28%), and poor workmanship in block laying (24%). The study recommends soil investigation as mandatory before foundation design for all residential projects in Kogi State.

Keywords: wall cracks, residential buildings, crack diagnosis, Kogi State, structural defects