California Government Code 51182, and Public Resources Code Sections 4290 and 4291, require that any person who owns, leases, controls, operates or maintains a building or structure in, upon, or adjoining any land covered with flammable vegetation shall at all times maintain 100 feet of defensible space.
Two zones make up the required 100 feet of defensible space. The two zones are: the home defense zone; and the reduced fuel zone (see "Defensible Space Zones, below). The home defense zone is within 30 feet of the house. The reduced fuel zone lies beyond the home defense zone and extends out at least 100 feet from the house or to your property line. Greater defense zone widths are necessary when your home is on a steep slope or in a windswept exposure. Specific recommendations for each zone are described below and pertain to the (LRA) Local Responsibility Areas that are protected by city or county fire departments.
Learn more about defensible space zones in this document.
Zone 1 (0 -30 feet)
Zone 1 extends 30 feet out from buildings, structures, decks, etc.
- Remove all dead plants, grass and weeds (vegetation).
- Remove dead or dry leaves and pine needles from your yard, roof and rain gutters.
- Trim trees regularly to keep branches a minimum of 10 feet from other trees.
- Remove branches that hang over your roof and keep dead branches 10 feet away from your chimney.
- Relocate wood piles into Zone 2.
- Remove or prune flammable plants and shrubs near windows.
- Remove vegetation and items that could catch fire from around and under decks.
- Create a separation between trees, shrubs and items that could catch fire, such as patio furniture, wood piles, swing sets, etc.
Zone 2 (30 – 100 feet)
- Cut or mow annual grass down to a maximum height of 4 inches.
- Create horizontal spacing between shrubs and trees. (See diagram)
- Create vertical spacing between grass, shrubs and trees. (See diagram)
- Remove fallen leaves, needles, twigs, bark, cones, and small branches. However, they may be permitted to a depth of 3 inches if erosion control is an issue
THE THREE R’s OF DEFENSIBLE SPACE
This technique involves the elimination of entire plants, particularly trees and shrubs, from the site. Examples of removal would be the cutting down of a dead tree or the cutting out of a flammable shrub.
The removal of plant parts, such as branches or leaves, constitute reduction. Examples of reduction are pruning dead wood from a shrub, removing low tree branches, and mowing dried grass.
Replacement is the substitution of less flammable plants for more hazardous vegetation. For example, removal of a dense stand of flammable shrubs and planting an irrigated, well maintained flower bed would be a type of replacement.
Choosing the right plans and spacing them properly can slow the spread of fire, reduce flame intensity, catch embers, and improve chances that your home will survive. Adding space between plants and shrubs reduces the likelihood that fire will spread. Space shrubs at least 2X the height of the mature plant.
As slope increases, spacing should be increased accordingly. Certain fire prone shrubs and trees, like juniper and cypress, are so flammable that they should be replaced with fire-resistant plants.
Limb and Maintain Trees
Remove lower limbs of conifers (pine, fir, cedar, etc.) so that no leaves or needles or within 10 feet of the ground, or 1/3 the height of the tree if it’s less than 30 feet tall. Space trees so that the canopies do not touch, with added space between fire prone species like conifers. Remove limbs within 10 feet of structures.
Trees like oaks, bay, and ornamentals with broad leaves should be limed so that no branches are within six feet of the ground, or 1/3 height of the tree if it’s less than 18 feet tall. A licensed arborist can help select a safe species and maintain your trees in good health for optimum fire resistance.