Methodology for Assessing the Thermal Effects of a Wildfire on a Structure

Wildfires cause billions of dollars’ worth of damage annually. Even when directly not consumed by fire, damage to structures have been reported and accredited to high temperature exposure and moisture content decreases resulting from a wildfire. It is difficult for insurance professionals to assess whether reported structural component or interior distress was the result of a surrounding wildfire event. A residence surrounded by a mountain wildfire in the western United States became the subject of an investigation into wildfire-related distress. The methodology utilized during this investigation is presented and detailed. Elevated exterior temperatures, and their durations, around the structure are inferred from heat damage to nearby flora, exterior building materials, etc. Heat flow analyses are conducted to determine the interior temperatures at which components were exposed. Thermal effects are modeled on a material-by-material basis to evaluate the effect of the determined temperature increase, and moisture content decrease, on distressed items reported to be wildfire-related. Although closely surrounded by a forest fire, much of the distress attributed to the wildfire was found to not be wildfire-related.