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Create a Wildfire-Resistant Landscape with Defensible Space
The leading cause of structures lost to wildfire are ignited by embers. Embers can travel miles ahead of an active wildfire; therefore, we need to think about defensible space. Defensible space is the buffer zone you create around buildings and structures. It involves modifying the surrounding vegetation and landscape such as grass, trees, shrubs and wildland area to create a more wildfire-resistant environment. When defensible space is thoughtfully created and well-maintained, it will increase the likelihood your building will survive a wildfire.
Wildfire–Resistant Landscape
A guide to modify your vegetation and landscape which creates a building buffer zone from wildfire.
Zone 0 (Noncombustible Zone): 0-5 Feet
It is crucial to establish a clear, noncombustible zone that extends 5 feet out from the exterior walls of your building. This noncombustible area should also be created around attached decks, covered patios, ramps, balconies, porte cocheres and stairs and unattached nearby structures like garbage containment and storage sheds. By implementing this zone, you can significantly reduce potential for ignition.
How to create a 5-foot noncombustible buffer
- Remove all vegetation and groundcover in the first 5 feet
- Remove all vegetation, grass, weeds shrubs, bushes, plants, trees, etc.
- Remove wood mulch, pine straw, rubber mulch, or other combustible ground covers.
- Trim back branches that overhang the 5-foot area.
- Do not allow vines to grow on buildings, fences, or other structures within 5 feet of the building.
- Install 5-feet of hardscape around your building
- Install groundcover material such as concrete, gravel, pavers, river rocks or steppingstones.
- Install 5 feet of hard groundcover surrounding any around attached decks, patios, ramps, balconies, porte cocheres and stairs and unattached structures like garbage containment and storage sheds.
- Replace combustible fencing within 5 feet
- Replace any wood or plastic fencing and gates within 5 feet of the building with a noncombustible fence, such as metal (aluminum or chain link).
- Replace combustible awnings
- Remove combustible awnings or replace awnings with noncombustible material such as metal.
- Maintain the 5-foot Noncombustible Zone
- Implement a maintenance strategy to keep the area clear of all tree debris, weeds, grass, and dead plant material at least monthly.
- Do not allow parking or storage of vehicles, boats, RVs, or ATVs. Ideally, vehicles stored on-site should be parked at least 30 feet away from the building.
- Do not store combustible items in this zone such as trash, cardboard boxes, wooden pallets, propane tanks, flammable liquids, etc. Small amounts of flammable liquids should be stored in fire-rated cabinets at least 30 feet away from the building.
Zone 1 - Extend your Defensible Space: 5-30 Feet
Choosing a limited number of well-spaced, fire-resistant plants can look good and be easy to maintain, as well as slow the spread of wildfire to your building.
How to eliminate fire pathways to your building
- Implement a maintenance strategy
- Cut grass to at most 4 inches and keep watered.
- Routinely clear tree debris such as leaves and pine needles.
- Make sure areas around fences and underneath gates are clear of debris, as this is another area where embers can collect.
- Remove dead vegetation, including piles from pruning and firewood.
- Trim trees
- Remove tree branches less than 6 feet above the ground.
- Trim tree canopies to ensure at least 10 feet of horizontal space between trees.
- Work with your neighbors to address trees near the property line that affect both properties.
- Ask your power company to remove branches that are near power lines. Never attempt to do this job yourself.
- Shrubs
- Choose low growing, fire-resistant plants.
- Relocate any shrubs located under or near trees.
- Keep low growing bushes and shrubs spaced out or in small groupings (no more than 3 shrubs) that will result in a discontinuous path of vegetation.
- Remove any hedges or rows of bushes that will create more fuel and a pathway for fire to reach your structures.
- Maintain structures near your building
- Place structures at least 10 feet away from the building or from any attached structures such as a deck or accessibility ramp.
- Install an enclosed structure for garbage containment.
- Create a 5-foot Noncombustible Zone around each structure.
- Ensure there is a minimum of 6 vertical inches (measured from the ground up) of noncombustible material at the base of each structure, like the building. For an elevated structure, enclose the base with 1/8-inch metal wire mesh.
- If you have multiple structures, such as garbage containment and a storage shed, ensure these structures are spaced at least 10 feet apart. Have at most 3 of these structures within 30 feet.
- Move any propane tanks from this zone to at least 30 feet away from your building and away from any structures.
Zone 2 - Reduce Fuels: 30-100 Feet
Maintaining vegetation within 100 feet of your building or to the property line will help reduce the intensity of a wildfire and slow its advance toward your building.
How to reduce fuel to reduce fire spread
- Clear landscaping debris
- Cut tall grasses to a height of 4 inches or shorter.
- Remove dead vegetation such as tree limbs, leaves, and pine needles, including piles from pruning on a regular maintenance schedule.
- Clear grass, weeds, and other vegetation from a 10-foot area surrounding any propane tanks.
- Trim trees
- Remove tree branches less than 6 feet above the ground.
- Trim tree canopies to ensure at least 10 feet of horizontal space between trees. Increase the spacing for trees on a slope.
- Work with your neighbors to address trees near the property line that affect both properties.
- Ask your power company to remove branches that are near power lines. Never attempt to do this job yourself.
- Shrubs
- Remove any shrubs located under or near trees.
- Keep bushes and shrubs spaced out or in small groupings (no more than 3 shrubs) that will result in a discontinuous path of vegetation.
- Remove any hedges or rows of bushes that will create more fuel and a pathway for fire to reach trees or structures.
Critical Business Prep
These fundamental, critical steps serve as a starting point before progressing to the next set of actions. If you’re ready, proceed to Exterior Building Upgrades.
Exterior Building Upgrades
After addressing the critical building prep, this group of larger building improvements will give your structure additional levels of protection.
Wildfire-Resistant Landscape
When defensible space is thoughtfully created and well-maintained, it will increase the likelihood your building will survive a wildfire.
Business Evacuation Steps
When wildfire may threaten and time allows, follow these last-minute steps to protect your building.
