Experiments to provide the scientific-basis for laboratory standard test methods for firebrand exposure

Firebrand ignition of structures is a major factor in large outdoor fire spread. Standard laboratory test methods are required to evaluate and compare the performance of different building elements and/or vegetative fuels ability to resist firebrand ignition. It is important to determine full-scale assembly performance when exposed to firebrand showers since weak points in a given assembly can be investigated. Such studies will lead to determining the necessary configuration of building component mock-ups that can be used in standard laboratory test methods. The basis of this paper is to present a comparison of results from full-scale roofing assembly experiments, to mockups using the recently developed experimental capability at National Research Institute of Fire and Disaster (NRIFD). The results demonstrated that similar firebrand penetration behavior/trends were observed for mock-ups of full-scale roofing assemblies, as compared to experiments where full-scale roofing assemblies were used, all under similar wind speeds. The experimental findings presented in this paper represent an important step to develop reduced-scale test methods for firebrand exposure.