Fire-Induced Charring of Common Residential Siding Types

The increase in the number and severity of wildfires over recent years due to the recent expansion and growth of rural areas has led to an increased risk of wildfire damage for structures at the Wildland-Urban Interface (WUI). This paper investigates the feasibility of permanent passive fire protection to protect homes and communities from the damage caused by wildfires using flame-resistant materials easily applied during new construction or installed in retrofitting existing structures. This proposed method of protection would provide continuous protection without any lengthy set up required for immediate wildfire protection and would limit fire damage to the most external and easily replaceable components of a structure. Small scale models were tested using five different flame-resistant materials and three types of siding including: wood siding, vinyl siding, and hardie board. Thermocouples were placed in 9 different locations of the models, and the percent difference in temperature between thermocouples on the exterior and interior of the front facing walls was calculated to compare the performance of the different types of siding. An evaluation of char was also conducted to analyze the effectiveness of each type of siding against direct flame contact. Preliminary results show that hardie board provided the most protection in the event of a wildfire because it prevented charring of the internal components of the model and minimized change in internal temperature.