The issue of exterior fire threat to buildings, from either wildfires in the wildland-urban interface or neighboring structurefires, is critically important. To address this, theWildfire Ignition Resistant Home Design (WIRHD) program was initiated. TheWIRHD program developed a tool, theWildFIREWizard, that will allow homeowners to estimate the external fire threat to theirhomes based on specific features and characteristics of the homes and yards. The software then makes recommendations to reducethe threat. The inputs include the structural and material features of the home and information about any ignition sources or flammableobjects in its immediate vicinity, known as the "home ignition zone."

The tool comprises an ignition assessment model that performs explicit calculations of the radiant and convective heatingof the building envelope from the potential ignition sources. This article describes a series of material ignition and flammabilitytests that were performed to calibrate and/or validate the ignition assessment model. The tests involved exposing test walls withdifferent external siding types to radiant heating and/or direct flame contact.The responses of the test walls were used to determinethe conditions leading to melting, ignition, or any other mode of failure of the walls. Temperature data were used to verify themodel predictions of temperature rises and ignition times of the test walls.

Presented at Thermal Performance of Exterior Envelopes of Whole Buildings XII, December 2013