Post-Flashover fires in light and heavy timber construction compartments

A series of fire experiments was performed to study the gas temperature development and charring behaviour of timber construction compartments. The measured gas temperatures were 300-500 C lower than predicted by the parametric temperature-time curves of Eurocode 1 for unprotected and insufficiently protected timber structures. For structures protected with a double layer of gypsum plasterboard, the agreement was better. In all cases, however, the prediction was on the safe side. One protective layer of gypsum plasterboard delayed the onset of charring for 20 min. Using two layers, the delay time was doubled. Reduced charring rates for long exposure times were observed, resulting from the increasingly protective effect of the char layer withtime.