How to Protect Your Home Against Wildfires

The Growing Threat

As I drink my coffee this morning in sunny California, our state fire agency “Cal FIRE” notes 18 large wildfires statewide, and tens of smaller fires that generally are handled by local fire departments. Some have required residents to flee wind-driven flames, and this early in the fire season have already caused injuries and deaths. While a number of these fires have some connection to July 4th fireworks, we know from experience that lightning, vehicle activity, and poorly-tended open fires will continue to fuel what’s expected to be a significant fire season in light of the drought-busting rain we received during the winter.

What is a wildfire?

Wildfire (also called “wildland fire” or “wildland-urban interface fire”) is a natural process that periodically renews forest and semi-arid landscapes, and allows certain plant species to propagate. When allowed to naturally occur, these fires thin seedlings in forests, and burn cool enough to be a positive force on flora and fauna.

What is the human impact on wildfire?

Enter mankind, and our predilection for building communities on the very edge of beautiful natural environments. Suddenly, the fires which are part of the wild environment are now a threat to our homes, and therefore due to public demands must be suppressed at all costs. Decades of development in historically fire-prone areas and routine suppression of all wildfires has resulted in artificial concentrations of highly-flammable vegetation in many areas which kick up the intensity of normal fires into what we call “firestorms.”

What are firestorms?

Firestorms are characterized by rapid spread, total consumption of natural and man-made fuels, and difficulty of control. Often wind-driven, firestorms can propel burning embers 5 miles or more in advance of the flame front, creating spot fires in vegetation and igniting vulnerable structures including homes. Firefighters facing advancing fire are forced to do “structure triage,” an assessment of an individual building’s ability to be reasonably defended.

Components of structure triage include whether “defensible space,” a significant clear space between vegetation and the structure, is sufficient; if the roof is of non-combustible materials such as shingle or tile; if there is a water source such as a hydrant, pool or pond available to feed hose lines; and if the firefighters have a viable exit route should they need to evacuate. Other factors can include whether terrain is in the favor of the fire or the defenders, the proximity of combustible materials like firewood to the building, and weather conditions such as intense wind or thunderstorms.

How to Harden the Target: Protecting Your Home

Proactive Measures

The good news is that many of the risks to structures can be addressed well in advance of a fire. Take advantage of any programs offered by your local fire department. Even the smallest volunteer fire departments welcome the interest of residents who want to make the firefighters’ job easier.

A walk around your property with an experienced firefighter in exchange for cold lemonade is well worth the time. Trim some brush here, add smaller mesh attic vent covers there, and you see the benefit of a customized risk assessment and a fire crew who knows your property. Here is an example of a wildfire prevention program offered by the Orange County (California) Fire Authority.

Awareness

OK, so we’ve addressed the issues affecting your home. Now we have to talk about the safety of your family home.

Factors Affecting Fire Risk

The odds are in your favor that you will have some warning of an increased risk of wildfire. The biggest influences on wildfire risk are:

• “Fuel moisture,” a measure of how dry vegetation is based on seasonal weather influences.
• Wind, which can fan a small fire into a large one and quickly expand the fire perimeter.
• The fuels themselves, ranging from light grasses to oily brush (chaparral) to forest. The terrain in which the fire forms is also a significant influence.

Certain combinations of these characteristics can trigger wildfire warnings from fire agencies and weather forecasters.