Impact of Mass Timber Compartment Fires on Facade Fire Exposure

This study investigates whether timber surfaces that are initially exposed to fire or partially protected timber components can lead to a more critical fire exposure on the facade. Five full-scale fire tests were carried out. Three tests with a square compartment (4.5 x 4.5 m(2)) and two with a double-width compartment (4.5 x 9 m(2)). The tests were conducted with a high fire load density (1085 MJ/m(2)). While the first test was carried out in a non-combustible compartment, the exposed timber surfaces were subsequently increased in the other tests. The measured compartment gas temperature, heat release rate, temperature on the facade, flame heights along the facade, heat flux and velocities along the facade are presented in this publication. The influence of exposed or only initially protected timber surfaces on the fire impact on the facade is investigated with the help of these results. Finally, these findings are presented and compared with the results of other internationally conducted fire tests from literature. Additional structural fire load leads to an increase in temperatures on the facade. However, there is no significant difference in flame height between the tests. Another result was that an exposed mass timber ceiling leads to higher heat fluxes on the facade than an exposed mass timber wall.

Automated summary

This study investigates the impact of timber surfaces that are initially exposed to fire or partially protected on the facade fire. The research findings show that additional structural fire load leads to an increase in temperatures on the facade, but flame height remains relatively unchanged. Moreover, an exposed mass timber ceiling results in higher heat fluxes on the facade compared to an exposed mass timber wall.