Official reports show embers ignite between 60% and 90% of homes lost in wildfires. This article explains how ember-related house fires happen, and we'll outline steps that a homeowner can take to reduce their fire risks.
Research shows that embers—sometimes called "firebrands"—are the main cause of home ignitions during wildfires.
Studies across different regions confirm that embers ignite between 60% and 90% of homes lost in wildfires.
This seems counter-intuitive to our vision of seeing flames on a hill and fearing that they may creep down to ignite our dwelling.
Yes, flames burn down homes, but airborne embers are what start the fire.
United States Ember Research
California's Office of the State Fire Marshal states that 60-90% of home ignitions come from embers.
The CA Fire Marshal stated that 'most homes burned in wildfires catch fire from embers, not direct flames or heat.'
Source:
osfm.fire.ca.gov
Studies from major universities back up the fact that embers, not flames, are the most dangerous thing to a neighborhood.
A University of Idaho report notes that over 90% of wildland-urban interface home ignitions were caused by flying embers.
Source:
uidaho.edu
The University of Nevada also confirms embers cause up to 90% of home ignitions.
Source:
unr.edu
Canadian Observations on Embers
Canadian wildfire experts report similar findings to the United States'.
FireSmart Canada estimates about 90% of homes destroyed by wildfires ignite from embers, not direct flames.
Source: firesmartalberta.ca
A 2019 Insurance Institute study also found embers caused up to 90% of building ignitions.
Canadian wildfire guides highlight embers as the main threat to homes.
Source:
firesmartbc.ca
Australian Research & Ember Data
Australian bushfire studies show most homes are lost due to embers igniting nearby materials.
Australian fire authorities warn that wind-blown embers ("ember attack") can travel hundreds of meters ahead of fires.
Studies of the 2009 Black Saturday fires confirmed embers caused most home losses.
Source:
qra.qld.gov.au
Evidence From Major Fires in California
California wildfires provide clear examples of ember damage:
- Cedar Fire (2003), San Diego County: Embers ignited roof debris, decks, and yard materials.
- Tubbs Fire (2017), Sonoma & Napa Counties: Embers started home fires far ahead of the main flames.
- Glass Fire (2020), Napa & Sonoma Counties: Showed the need for ember-free zones around homes.
Research on the Witch & Guejito Fires (2007) found embers ignited about 75% of destroyed homes.
How Homeowners Can Protect Homes
Based on this evidence, here are key steps to protect your home:
Roofs and Gutters
- Install a Class A fire-resistant roof to block ember ignition.
- Clean gutters regularly and use metal gutter covers to prevent debris buildup.
Vents and Openings
- Cover vents with 1/8-inch or finer 'Ember Mesh' screens to block embers.
- Use metal covers on dryer vents and other openings.
Walls and Siding
- Use fire-resistant materials for exterior walls.
- Close off eaves and soffits to prevent embers from getting inside.
Windows and Doors
- Install dual-pane tempered glass windows to resist heat.
- Choose metal or fire-resistant doors.
Decks and Fences
- Build decks with non-flammable materials or solid surfaces.
- Avoid wooden fences attached to your home.
Defensible Space
- Create a non-flammable zone within 5 feet of your home by removing plants, mulch, and debris.
- Regularly clear dead grass, leaves, and branches from your yard.
Taking these steps can greatly reduce your risk of losing your home to wildfire.
Summary
Across North America, Australia, and other wildfire-prone regions, studies confirm embers ignite 60-90% of homes lost in wildfires.
This explains why fire safety programs focus on ember-resistant design and creating defensible space.
Preventing ember ignitions is the most effective way to protect homes during wildfires.
Sources:
- California Office of the State Fire Marshal: osfm.fire.ca.gov
- University of Idaho Extension: uidaho.edu
- University of Nevada, Reno Extension: unr.edu
- FireSmart Alberta: firesmartalberta.ca
- FireSmart BC: firesmartbc.ca
- Queensland Fire and Emergency Services: qra.qld.gov.au