A Case Study Comparing the Fire Risk in a Building of Non-combustible Frame and a Timber Frame Building

Abstract

In the last two decades, a considerable number of multi-storey apartment buildings have been constructed in the Nordic countries using timber as load-bearing material. Such constructions have earlier not been allowed by the authorities, mainly due to the fire risk. The Nordic countries there-fore co-operated for some years, within an organisation named Nordic Wood, with the aim of developing construction methodologies that seriously diminish the fire risk in timber-frame multi-storey buildings.

Authorities and industry found that it was necessary to develop a new fire risk assessment technique to verify that fire safety can be as high in timber-frame buildings as in other types of buildings, given that the right construction methods be used. Nordic Wood therefore initiated work that led to the development of FRIM-MAB, a Fire Risk Index Method for Multi-storey Apartment Buildings.

The method has been described in several reports and papers and was evaluated against a much more elaborate Quantitative Risk Analysis (QRA) method. Both the index method and the quantitative risk analysis were used to rank four different buildings with respect to fire risk and the ranking was identical. The method was then further tested, where 20 timber frame buildings in four Nordic countries were analysed.

This work has recently been taken further by comparing the fire risk in a building of a non-combustible frame in 6 storeys and a similar timber frame building. This paper reports on that comparison.