What contractors need to know about wildfires

The materials and design decisions made on a job site today determine whether a building survives a wildfire tomorrow. What was once considered a regional problem is now impacting construction in every state. Michele Steinberg, the National Fire Protection Association's wildfire division director, says the risk is growing faster than most contractors have adapted to. This new reality is prompting contractors to take a closer look at resilience, crew safety and how the built environment contributes to fuel loads. We asked Steinberg to share insights on how to mitigate the impact of wildfires on your construction business.

—Interview by Margot Lester, edited by Bianca Prieto

Why do contractors building in areas not historically prone to wildfires need to prepare for them these days?

Wildfires are a natural part of ecosystems across North America. They shape forests, rangelands and grasslands by clearing out dead material, making room for new plants and trees, and returning nutrients to the soil. Every state reports wildfire occurrences every year, with many of these fires staying small. Long-term climate changes have affected the historic occurrence and magnitude of wildfires, though. Extremes in temperature and precipitation lead to periods of drought that can make vegetation burn more readily. These are often followed by periods of heavy precipitation that grow more vegetation, which then dries out and becomes more flammable, creating more fuel for wildfire.

How should contractors in all regions think about wildfire and the built environment?

If construction contractors consider that a building represents fuel for a fire, they can take steps to limit the likelihood of it being ignited by wildfire. In fact, of the three ingredients for a fire to grow and spread—fuel, heat and oxygen—fuel is the only factor that we can control for in the design and construction of buildings. Research has shown repeatedly that the materials and design of structures make a significant difference in whether they will ignite from a wildfire. One building on fire can ignite a nearby building, start to create a domino effect and lead to a major conflagration. 

How do we reduce the possibility of ignition and spread?

The good news is that designing and building structures that can withstand a wildfire is possible. It doesn’t require expensive engineering solutions or specialty materials. To build a structure that withstands wildfire, start with noncombustible materials and assemblies. These include the roof, exterior walls, windows and any attached or [accessory] structures. Decks, patios, porches, staircases, fences, garages and sheds are all part of the fuel package of a building. If there is a way for embers or flames to ignite these elements, the fire will spread to the rest of the building.

The key design features to minimize structure ignition from wildfire are noncombustible roof covering and assembly, noncombustible or fire-resistive siding, dual- or triple-paned windows, protected vents or openings and noncombustible signage. In addition, keeping the first five feet of a building’s perimeter clear of combustible material, including mulch, reduces the potential for surface flames or embers to ignite building elements.

What's one way to improve crew safety when fire risk is high?

Keep up to date with weather forecasts and emergency warnings. Situational awareness about prolonged hot, dry weather and strong winds is important, since these are the weather factors that can enable any wildfire that ignites to grow and spread. Ensure that workers on site, as well as those traveling to and from a job site, are all able to communicate should an emergency arise. Having a plan to evacuate workers from a danger zone is critical. Safety on the job site should include a ban on smoking materials and careful handling of any open flame. NFPA 241, Standard on Safeguarding Construction, Alteration, and Demolition Operations, provides details on how to prevent fires for buildings under construction.

 
Where can contractors get more information on wildfire readiness, resilience and materials?

NFPA provides training and a wealth of information on safeguarding construction, alteration and demolition operations; fire prevention during welding, cutting and other hot work; and wildfire risk reduction. Most options are low cost or even free of charge and can be found at NFPA.org.

As every state’s regulations differ around building and retrofitting in wildfire risk areas, it’s important to connect with the relevant authorities having jurisdiction to ensure safety and regulatory compliance. Our wildfire resources include a broad network of state agencies and local jurisdiction representatives engaged in wildfire risk reduction through the voluntary Firewise USA® recognition program.

What else should we know?

Construction contractors have a unique and important role in ensuring that the buildings they create are safe and sustainable. With good design and fire-resistant materials, their work can make a significant difference in the future outcomes for owners and residents when a wildfire occurs.

Get more insights on construction and climate resilience.

Steinberg's point is worth internalizing: a building is fuel. Every design decision—roofing, siding, vents, the mulch around the perimeter—either reduces or increases the odds that an ember ignites it. Contractors don't need expensive materials to build for wildfire resilience. They need to start thinking about combustibility from the design phase, not after the framing goes up.