As urban infrastructure further develops covering increasingly larger areas, wildfires pose a severe threat to buildings and human life. Therefore, protecting a structure that is subjected to such fires is a significant challenge.
The current research was motivated when people living in fire prone areas contacted Fumiaki Takahashi, lead author of the study and Professor at Case Western Reserve University of Cleveland. They wished to find out whether common materials could protect a structure from a wildfire. “I thought about a means to reduce wildland fire damage and found a U.S. patent ‘conflagration-retardative curtain’ i.e., a fire blanket, issued during World War Two. In addition, the U.S. Forest Service firefighters managed to save a historic forest cabin by wrapping it with their fire shelter materials,” Prof. Takahashi, stated.
A number of fabric materials were subjected to laboratory testing in order to determine if they can protect buildings. In particular, 4 fabric materials (fiberglass, pre-oxidized carbon, aramid and amorphous silica) each laminated with or without an aluminum foil, were tested to derive their insulation capacity against radiation heat or fire contact. Moreover, scale testing from small structures (e.g. a birdhouse) to a full-size repository was conducted. The fiberglass and amorphous silica fabrics laminated with aluminum surface performed best as they presented high reflection and emission of heat radiation.
The results showed that current blanket technology could perform well and save a building from severe damage if exposed to a short duration of wildfire. Nevertheless, those materials and their implementations methods should evolve in the future to increase the chances of success. "The whole-house fire blanket is a viable method of protection against fires at the wildland-urban interface. Current technology can protect an isolated structure against a relatively short wildfire attack and further technological developments are likely to enable this method to be applied to severe situations,” Prof. Takahashi added.
Difficult tasks that arise include the application of the method in a multi-structure system to protect a community and the feasibility of the aforementioned materials to withstand a fire with longer duration.
Prof. Takahashi emphasizes that fire blanket technology would highly reduce the risk that people living in fire prone areas are exposed.