Modelling thermal performance of gypsum plasterboard‐lined light timber frame walls using SAFIR and TASEF

Gypsum plasterboard is commonly used as a lining material on lightweight timber or steel framing. Gypsum contains moisture, both free and chemically bound in its crystal structure. The dehydration of the gypsum and decomposition of calcium carbonate absorb heat giving gypsum plasterboard fire resistant qualities. This paper discusses the suitability of the finite element heat transfer program SAFIR for modelling plasterboard-lined light timber frame assemblies and its limitations. The default material properties in SAFIR for gypsum plasterboard do not give good results and ‘smoothing’ of enthalpy curves has insignificant effects on the results but substantially reduces processing time. Modelling with SAFIR gives similar results to prior modelling using the program TASEF with slight differences. Both programs give better overall results for slower developing fires and furnace tests than more rapidly growing fires. Reasonable, slightly conservative results for thermal analysis of heat transfer through the walls and into timber studs can be achieved using the parameters suggested in this paper. More sophisticated and detailed models incorporating mass transfer, effect of fasteners, gaps between lining sheets and ablation are required to achieve better comparisons. Copyright © 2010 John Wiley & Sons, Ltd.