Fuel breaks are natural or constructed breaks in vegetation, used to stop or control the spread of fire.
They are usually constructed by slashing or spraying. Water bodies or green crops can also act as breaks.
Types of fuel breaks
Slashed or mown fuel breaks (grasslands)
- Are the most common types of fuel breaks
- Will NOT prevent fire spread but will reduce flame height, making fire easier to control.
Bare earth breaks
- Are ploughed, graded, burnt or sprayed
- May stop a fire under low fire danger conditions without anyone actively fighting the fire
- Will behave more like a slashed break if there is some fuel left sitting on the surface (fire will often move across slashed or mown breaks unless someone actively puts it out)
- May require a permit if they remove native vegetation.
Burnt breaks
- Can be effective if properly established
- Should only be carried out with appropriate permits and by people with experience in burning operations
- Should be carried out with consideration for environmental issues.
Herbicide breaks
Herbicide can be used to create a bare earth fuel break or a break where dry fuel is still present but the fuel load has been reduced. It can also be used to reduce fuel loads to make fuel reduction burning safer and to keep fences - including electric fences - clear of weeds and grass.
The most effective time to apply herbicide is in early spring before grasses and weeds have grown.
Vertical breaks
Fires which burn through the crowns of trees are intense and difficult to suppress so it is important to minimise 'ladders fuels' that allow fire to move upwards.
Vertical breaks can be made by pruning, slashing, or removing bark:
- Long ribbon bark can be removed by hand
- Some types of bark can be burnt
- Always seek specialist advice before burning or removing bark to maintain good tree health.
Reduce ladder fuels by:
- Pruning lower branches to around 2 to 2.5 m
- Pruning shrubs so that their tops are well away from the lower branches of trees
- Pruning the lower branches of shrubs to separate the foliage from the surface fuels underneath.
Internal fuel breaks (timber and farm forestry plantations)
These can limit the spread of fire. Breaks that incorporate an access track can also be useful for fire suppression purposes. Consider having internal fuel breaks between different enterprises such as farm forestry and cropping.
Perimeter fuel breaks
Establish a perimeter fuel break around your property where practical and environmentally sound.
Consider fire behaviour factors and fuel loads on adjoining lands when establishing your perimeter break.
What makes a fuel break effective?
Weather conditions and fire behaviour influence the effectiveness of a fuel break, as does the width or proportion of the break. Wider fuel breaks will stop more fires in different conditions.
Fuel breaks are effective when:
- Close to the source of fire ignition so that the fire has not built to its maximum potential
- Approached by the side (flank) of the fire, which has lower intensity than the front (head) of the fire
- Able to disrupt the continuity of the fuel, thereby reducing fire intensity
- Nearby trees are not producing embers.
Wind Breaks (Shelterbelts)
Windbreaks are areas of vegetation that are designed and planted to reduce wind impact on stock and crops on farms. These should be managed for fire risk, but consider options such as reducing adjacent fuel loads rather than pruning or thinning.
