Fire protection of wood by different gypsum plasterboards

Cone calorimeter tests were performed on specimens made of pieces of wood and pieces of gypsum plasterboards protecting the wood against the heat. The thermal behaviour of the gypsum plasterboards of different origin was studied by determining the time to onset of charring and the charring rate of wood. The specimens were exposed to a constant heat flux of 50 kW/m². The test results show that the time to onset of charring is more dependent on the board thickness than the area weight of the boards. The charring rate is fairly well predicted both by the board thickness and area weight, the latter being slightly better as a prediction parameter. The mechanical board properties needed in order to fully understand the fire protection from gypsum plasterboards were not studied in this investigation. Copyright © 1999 John Wiley & Sons Ltd.