EFFECT OF SIDING TREATMENT ON FIREBRAND PRODUCTION FROM BUILDING COMPONENTS
Samuel L. Manzello, Sayaka Suzuki
Wildfires which spread into a community, commonly known as Wildland-Urban Interface (WUI) fires, is a significant problem all over the world. Post-fire investigations have suggested that firebrands are the major cause of structure ignitions. Yet, few studies on firebrand production, as well as its ignition, have been conducted as most firebrand research has focused on its transport. In order to understand the mechanism of WUI fire spread and growth, it is necessary to understand firebrand production both from vegetation and structures. To this end, firebrand production from real-scale building components under well-controlled laboratory conditions was investigated. Re-entrant corner assemblies were ignited and during the combustion process, firebrands were collected to determine the size/mass distribution generated from such real-scale building components under varying wind speed. In prior work, a unique ignition methodology was developed to generate firebrands from re-entrant corner assemblies constructed of wood studs and oriented strand board (OSB). In this study, this ignition methodology was applied to re-entrant corners constructed from wood studs/OSB but fitted with actual siding treatments (cedar siding along with tar paper) to determine the influence of siding treatments on firebrand generation from wall assemblies. Firebrands were collected with pans filled with water, and then the size and mass of firebrands were measured after drying. The size and mass distributions of firebrands collected in this study were compared with the data from prior component tests by the authors as well as the limited studies available in the literature on this topic. Some firebrands were found to be lighter for a given projected area than others, likely produced from cedar siding or tar paper. The effects of applied siding treatments on firebrand production will be discussed in more detail.