Effective factors on the performance of woven wire screens against leaf firebrand attacks

Abstract

Firebrand spotting is the dominant wildfire propagation mechanism. The use of wire screens to prevent firebrand entry into structures is recommended or mandated by many standards. The existing standards address only one feature of screens which is opening size. This experimental study aims to explore several other factors that may influence the performance of wire screens and may need to be incorporated in codes and standards development process for structures located in wildfire-prone areas. The results demonstrate a previously unreported shattering mechanism in the case of Eucalyptus populnea (from the Myrtle family) leaf firebrands under a moderate wind speed of 14.5 m s−1. The results also show that screen porosity, screen type and wind speed would be appropriate to be addressed in developing standards, but there is no need for concern about screen orientation as long as the screen is placed perpendicular to the wind direction during the experiment.