Wooden materials in building projects: Fitness for roof construction in southwestern Nigeria

摘要

A survey of building projects in south-western, Nigeria was conducted to assess wood usage in building roof projects in the zone and to determine the efficiency of wood utilization in building constructions prior to and during oil economy in south-western Nigeria. Based on various purposes of wood utilization in building projects, wood usage in building can be classified as structural, functional and decorative/aesthetics. Buildings in the rural area have the worst wood usage efficiency followed by roofs in the sub-urban area, while roofs in urban area are partially efficient. Based on roofing condition alone, approximately half of all the buildings surveyed (n = 1720) in the three zones are categorized as either substandard or deemed to have failed. Based on functional consideration, some of the urban and sub-urban housing roofs and only few of the rural areas attained the good-scoring grade. This is attributed in part to many houses owned by low income earners, which means the houses are built to satisfy emotional needs while engineering factors such as strength of materials and structural purposes are ignored due to lack of strong government policy on housing standard in the country. More than half of the roofs surveyed have least or more identified major defects. Recommendations include government directed policy on the minimum housing standard; possible built and lease programme for the low income earners; a vigorous programme of housing and health education; enhanced collaboration between stakeholders to develop enforceable standards for existing housing stock and future builds.