Wildfires – Conflagration Continues

Aon Benfield invited IBHS to contribute perspectives on significant weather events during 2018 for the Weather, Climate & Catastrophe Insight: 2018 Annual Report developed by Impact Forecasting, a wholly owned subsidiary of Aon. We were proud to offer guidance and insights on both hurricanes and this piece on wildfire.


The 2018 California wildfires, including the Carr, Camp, and Woolsey Fires, put exclamation points on the frightening lessons offered by the Tubbs and other 2017 wildfires. Coffey Park demonstrated last year that wildfire risk extends well past the Wildland Urban Interface (WUI) and reaches right into tidy suburban neighborhoods. At that point, the structures themselves become part of the spreading wildfire, a risk that is not included in the models used to develop hazard zones in California.

As a result, the vulnerability of thousands of communities and neighborhoods remains a significant knowledge gap that must be closed. In the meantime, home and business owners need to adopt a more defensive mind set. We cannot wait for definitive labels—which a wildfire can readily disregard—while the countryside burns.

Wildfire doesn’t have a single, lasting solution at any level. State and federal efforts can improve funding and execution of ongoing forestry management and wildland vegetation strategies, along with additional training and capacity to fight wildfires. These defenses are powerful, but require time, political courage, and community will. Meanwhile, homeowners should follow the age-old wisdom that the best offense is a great defense, and work to mitigate risk.

Here again, wildfire mitigation is not a one-and-done effort. It requires vigilance, maintenance, and team spirit. Even the most fire-resistant property can burn if neighbors around it ignite. Wildfire resilience is an all-for-one, one-for-all activity. All homeowners should be aware of these details:

Maintain defensible space

  • A 5-ft non-combustible zone surrounding the house, where no combustible material is allowed, reducing the chance of wind-blown embers igniting materials near your home, thereby exposing it to flames
  • A 5-30 ft zone, creating a landscape that will not readily allow fire to burn to the home
  • A 30-100 ft zone, reducing the energy and speed of the wildfire

Use fire-resistant building materials

  • Class A roof assembly
  • Noncombustible siding or a 6-inch clearance from the ground to the siding
  • Use of metal drip edge to protect roof deck
  • Use of attic vents that mitigate against ember penetration

Paradise proved that burning structures can drive the spread of wildfires, and we need to add this data to wildfire risk models that inform hazard zones in California. The Joint Fire Services Program characterizes the differences between embers generated from vegetative fuels and structural fuels.

Additional effort is required to incorporate this new information into fire spread models, and into the tools that differentiate the vulnerability of individual communities.

Weather, Climate & Catastrophe Insight: 2018 Annual Report