Development of Models for Charring Rate of Selected Construction Timber Species in Southwestern Nigeria

The performance of Nigeria timber species under fire exposure to prevent collapse of structure has not been adequately investigated. This study was to determine the charring rate models of some selected timber species mostly used for constructional purposes in Southwestern Nigeria. Six species out of ten identified timbers were selected for studies. They are: Afara, Iroko, Opepe, Mahogany, Mansonia, and Teak. The densities of the timber species were determined at Moisture Contents (MC) of 9.0, 12.0, and 15.0%. Samples from each of the selected species, were exposed to fire at temperature ranges of 20° to 230° C for 30 minutes; 20° to 300° C for 60 minutes; 230° to 600° C for 30 minutes. Empirical statistical model was developed for charring rate of the timber species. The models were analysed using ANOVA at . At 30 minutes fire exposure (20 to 230° C), Afara of 9.0, 12.0 and 15.0% MC had the highest mean charring rates of 0.84±0.02mm/min, 0.82±0.02mm/min and 0.82±0.02mm/min respectively, while Opepe had the lowest charring rates of 0.48±0.02 mm/min, 0.48±0.02 mm/min and 0.47±0.02 mm/min at the three MC levels. This study indicated that density was a major predictor of the charring rate of constructional timber. Opepe which had the highest density also exhibited the lowest charring rate of all the species tested and is useful and recommended to ensure the safety and comfort of occupants in case of fire outbreaks.