A series of experiments were conducted to examine potential vulnerabilities of wood decks to continuous, wind-driven firebrand showers. Sections of wood decks (1.2 m by 1.2 m) were constructed and attached to a re-entrant corner assembly. The deck/reentrant corner assembly was then exposed to continuous, wind-driven firebrand bombardment generated by the newly developed NIST full-scale Continuous Feed Firebrand Generator (NIST full-scale Continuous Feed Dragon) installed in the Building Research Institutes (BRI) Fire Research Wind Tunnel Facility (FRWTF). The type of wood decks used, as well as the placement within a reentrant corner assembly, was based on input received from a decking ignition vulnerability workshop that NIST held in California in 2011. Three different wood decks types were exposed to wind-driven firebrand showers at wind speeds of 6 m/s; Cedar, Douglas-Fir, and Redwood. For each wood deck tested (exposed to a total firebrand mass flux of 17.1 g/m2s), firebrands were observed to accumulate on the deck surface, and due to continual glowing firebrand bombardment, each wood deck type was observed to ignite by flaming ignition. The average time to flaming ignition was 437 s for Cedar, 934 s for Douglas-Fir, and 756 s for Redwood. Therefore, wood decks were observed to be vulnerable to ignition from continuous, wind-driven firebrand showers. Results of these experiments are discussed in detail.
Proceedings Title: Fire Safety Science - Proceedings of the Eleventh International Symposium
Conference Dates: February 10-14, 2014
Conference Location: Christchurch, -1
Pub Type: Conferences
WUI fires, firebrands