Last year alone, California lost 4.3 million acres of land, 10,488 structures and 33 lives to wildfires throughout the state. Fire season is a typical occurrence in states like California, Texas, Colorado, Arizona and other dry states in the western US. Devastating statistics like these are the reason why fire resistant construction matters to us as architects and designers.
So, what is fire resistant construction? By definition, fire resistance is determined by specific properties of individual materials or larger material assemblies that prevent or retard the passage of excessive heat, hot gases and/or flames into a building. Fire resistive construction can be implemented for a multitude of different reasons that are dictated by various fire codes that take into account building type, use, height, size and location. Additionally, Wildfire Urban Interface zones can be a big determining factor in the need for fire resistant construction. The concept of W.U.I. was introduced in 1987 and in the year 2000 adopted into the National Fire Plan. These zones are mapped in each state and can be found through most governments webpage. Understanding when and why fire resistive construction is required is a key component in overall building design and helps to set guidelines to follow for both life safety, constructability and aesthetics.
When designing a building where fire resistive construction is required, it is important to remember that the main goal is to prevent the intrusion of unwanted heat and flames. According to the Insurance Institute for Business and Home Safety, 90% of homes and buildings that are damaged or destroyed throughout California are first ignited by intrusion of embers rather than from direct exposure to flames from a wildfire itself. Using a combination of non-combustible materials and intrusion-resistant roof ventilation systems, a fire resistant building design can be achieved.
Fire resistive materials are generally simple. Materials such as brick, concrete, stucco and gypsum board all classify as non-combustible fire resistant material and are very common in fire resistive construction. There are also newer, more all-in-one solutions such as insulated concrete forms, which are easy to install and provide benefits such as durability, strength, insulation and fire resistance in one package. Additionally, there are companies like BONE Structure that have created an all-in-one prefabricated material assembly that provides construction efficiency, sustainability, and fire resistance. BONE Structure not only achieves fire resistance but also provides structural systems with a well-sealed thermal envelope and integrated MEP systems, all wrapped with a modern exterior finish.
As wildfire severity has overwhelmingly increased over the last few years, more and more fire resistive construction solutions will continue to be developed. Although there is no guarantee of fire teams being able to save a home, fire resistant materials increase the likelihood of preserving homes and other buildings longer during a wildfire and provide a better chance for the space to be saved. We have to remember that the ultimate goal with fire resistive construction is life safety and preservation; the longer the building can withstand ignition, the longer the opportunity for occupants to escape and for fire teams to attempt to protect the building. If we can continue to design with these goals in mind, we will stand a better chance against wildfires when they threaten disaster.
Written by Aaron Golab