There are several ways a building can catch fire during a bushfire.
Ember attack
The main cause of building damage during bushfires is when embers and sparks enter the building through unprotected openings.
Flying embers or sparks can start small fires well before the main fire front arrives, or many hours after.
These small fires can quickly develop and engulf a whole building if not put out.
Direct flame contact
Direct flame contact occurs when vegetation or other flammable materials close to a building ignite, causing flames to come in direct contact with the outside of the building.
Radiant heat
Radiant heat is the main cause of people dying in a bushfire, but it rarely causes buildings to catch fire.
In extreme cases, radiant heat may ignite timber directly, but this only happens when a large quantity of fuel burns close to a building.
Radiant heat can shatter glass and allow sparks, embers and flames to get into a building.
Radiant heat may also heat up a building, making ignition by embers easier.
What happens to a building during a bushfire?
Embers and debris can start small fires around your home even when the main fire is kilometres away.
It only takes one ember to land in the right place for a small fire, called a ‘spot fire’, to start.
Spot fires grow into large fires and can form new fire fronts that sweep through areas.
