DEFENSIBLE SPACE - DEFINED
ACFSC advocates fire safety everywhere.  Fire can start from natural and man made causes.  The
Old Fire of 2003 was arson caused.  Thousands of homes and several lives were lost during the
fourteen fires burning in late October known as the California Wildfire Siege of 2003.
Preparation for fire is paramount to security and safety of anyone living in the “WUI” (Wildland
Urban Intermix) areas of the San Bernardino Mountains.

This section is about "Defensible Space".  The information provided below, will help readers
understand what Defensible Space is, and how to protect their property and lives by application of
the principles.
Defensible Space is a 100 foot fuels treatment clearance area surrounding any
structure, according to Public Resource Code section 4291.  To read the exact law,
click here.
ACFSC continues to initiate programs such as:
•        Defensible Space around homes
•        Chipper Day Projects
•        Block Coordination Fuel Reduction with agencies
•        Biomass alternative use sponsorship
•        PowerFlares in place of traditional Fusee use
•        Neighborhood fuel reduction projects
•        Community Wildfire Protection Programs
•        Community Emergency Planning
•        Evacuation Preparation
•        MAST coordination (Mountain Area Safety Taskforce)     
Defensible Space
Arrowhead Communities Fire Safe Council

Key Points
•        Wildfire will strike the weakest link in the defense measures you have taken on your property.
•        The type of roofing material and the quality of "defensible space" surrounding a home is a key factor in
whether the home will survive a wildfire.
•        Even small steps to protect your home and property will improve the chances your home will withstand fire.
•        Defensible space includes taking steps to “Fire Safe” all areas of your property, not just the immediate
vicinity of the house.

Defensible Space does not mean you must remove all of your trees and vegetation to protect your home and
property from catastrophic wildfire.  It means you selectively reduce vegetation while maintaining visual integrity
and some privacy screening by leaving the healthiest vegetation and trees in place. Aesthetics of your property is
important to every homeowner, but preservation of your home from wildfire is a top priority.

Steps to attaining defensible space:
•        Rake and remove flammable vegetation or debris within 100 feet of any part of the home or structure (PRC
4291)
•        Remove hazard trees
•        Thin weakened, dead, and over-crowded trees
•        Remove understory vegetation that can transport wildfire to tree-tops by cutting all branches hanging to
within 13 feet of the ground.  Pruning techniques - graphics: click here.
•        Chip remaining slash on site
•        Stack Firewood away from the structure (not under decks) and cover with a tarp.

Benefits:

•        Reducing wildfire risk and makes communities safer from the threat of wildfire
•        reduces risk of disease and insect damage to trees
•        increases property values
•        improves wildlife habit
•        improves scenic views
•        reduce a wildfire’s intensity, enough to prevent the fire from igniting the building
•        improves accessibility in forested areas
•        restores forest health
•        allows firefighters a chance to safely defend the house, in the event of fire
•        can also help prevent a house fire from spreading to the surrounding vegetation and other homes












Above Drawing:  X = crown spacing; Y = stem spacing. Do not measure between stems for crown -- measure
between the edges of tree crowns.

Details of Defensible Space:
•        Treatment means thinning (removing) trees and shrubs within 20 feet of each other
•        Dry grass and weeds are mowed to a height of less than 6 inches for a distance of 30 feet around
structures.  
•        Tree branches are pruned up to a recommended height of 10 feet, but not less than 6 feet, above the
ground.
•        Extended areas require “treatment” within 30 feet around a structure including thinning overstocked trees
and shrubs, and removing all low hanging branches
•        Immediately adjacent to structure keep 15 feet clear of all flammable vegetation.  
•        On sloped property, treatment extends 100 feet when 15% slope (a drop of 15 feet every 100 feet from
structure)
•        Greater than 15% slope requires treatment up to 150 feet
•        All slash and debris is chipped or hauled away.  (Burning slash piles is only allowed with approved burn
permits issued by the California Department of Forestry and Fire Protection, and limited to specific areas.)
•        Ladder fuels can transport the fire from the ground to the crowns of large trees. Ladder fuels from beneath
large trees are removed.
•        Branches are trimmed which extend over roof eaves. Pine needles and leaves are cleaned from roofs and
gutters. Woodpiles are located at least 30 feet from structures.

Defensible space must be maintained annually since the forest continues to grow.  Practice defensible space and
you will preserve our precious natural resources and enhance enjoyment of your home.