Risk-based attestation of fire safety of wooden facades in concrete-framed residential multistory buildings

This study presents a fire risk analysis on the impact on fire safety of installation of a wooden façade to a suburb residential multistory building belonging to the fire class P1 defined in the National Building Code of Finland, which in practice means a concrete framed building. The risk analysis and the associated fire simulations are made using state-of-the-art techniques in the fire safety sciences and technology. The results of the study reveal that with respect to the overall fire safety of the concrete-framed residential multistory buildings, the role of the combustible wood as the façade material is insignificant: as is inevitable, the calculations bring out a small increment in the probabilities of fire spread from the room-of-fire-origin to the apartments above, but this increment is small as compared to the influence of several other factors which are not regulated by the Fire Regulations. In particular, the relatively small amount of wood on the façade that is likely to contribute to the external flaming would cause a much higher risk if it was installed as a lining inside the apartment-of-fire-origin. It is shown that the results obtained for the selected example building can be generalized to other buildings with reasonably similar characteristics.