Assessment of construction defects on multistory commercial buildings in Jimma town

Abstract

A building defect can be defined as a material, component or finish which does not meet its accepted performance criterion. The main objective of this study was to assess the construction defects of multistory commercial buildings in Jimma town. Data was collected using observational checklist and questionnaire. Currently, there are a total of 64 multistory commercial buildings that are fully operational; from which 18 buildings are taken for the study by using purposive sampling method. Structured questionnaires were developed and distributed to randomly selected consultants, contractors and clients currently engaged on building construction. The questionnaire was utilized by involving 36 respondents from which, 22% (8) clients, 44% (16) contractors and 34% (12) consultants. According to the observational analysis result, the most common construction defect on commercial buildings, which was observed on 83.3% of the buildings, was plastering crack. The next frequent construction defects were peeling off paint (72.2%), broken/cracked floor tiles (66.7%), defective water supply system (61.1%) and exposed electrical wiring (55.6%). As the causes of the construction defects were assessed by the computed weighted average in the questionnaire analysis, workmanship problem is found to be the first cause of construction defects in multistory commercial buildings. The second and third causes of construction defects were using defective construction material and non-conformance with specifications, respectively. A questionnaire analysis was also used to investigate the impacts of construction defects on multistory commercial buildings. According to the weighted average of the responses, high maintenance and rework cost is found to be the first impact of construction defects. The second impact of construction defects is the decrement of building functionality. Dissatisfaction of property owners is found to be the third impact of construction defects. According to respondents’ weighted average applying an effective quality control mechanism is believed to be the first defect reducing measure. The second defect reducing measure is regular site supervision during construction work. Creating the necessary awareness for low-skilled laborers is the third recommended defect reducing measure. Since commercial buildings accommodate many people, the safety, serviceability and aesthetics value of the buildings should be monitored by the concerning governmental body, that is, Jimma town construction office.