Creating an Effective Survivable Space
Jan 26, 2018 09:05AM
● By Editor
Is there at least a 30-foot-wide area surrounding your home that is “Lean, Clean and Green?”
Lean…small amounts of flammable vegetation.
Clean…no accumulation of dead vegetation or other flammable debris.
Green…plants are healthy and green during the fire season.
[Prune: Branches and limbs 6-10 feet off the ground on all trees within a 30 to 100 foot radius of buildings.]
[Remove: Limbs within 10 feet of chimney, and dead limbs overhanging buildings.]
[Screen: Half-inch mesh screen on chimney outlet.]
[Clean: All needles and leaves off roofs and out of gutters.]
- Emphasize the use of low-growing herbaceous (non-woody) plants that are kept green during the fire season. Herbaceous plants include lawn, clover, a variety of ground covers, bedding plants, bulbs, and perennial flowers.
- Deciduous ornamental trees and shrubs are acceptable if they are kept green, free of dead plant material, ladder fuels are removed, and individual plants or groups of plants are arranged in a manner in which adjacent wild-land vegetation cannot convey a fire through them to the structure.
- Where permitted, wild-land shrubs and trees should be removed from this zone and replaced with more non-woody plants such as flowers. Individual specimens or small groups of wild-land shrubs and trees can be retained so long as they are kept healthy, free of dead wood, and pruned to reduce the amount of fuel and height, and ladder fuels are removed.
- For some areas substantial removal of wild-land vegetation may not be allowed. In these instances, wild-land vegetation should conform to the recommended separation distances, should be kept free of dead plant materials, pruned to remove ladder fuels and reduce fuel load, and arranged so it cannot readily convey a fire from the wild-lands to the house. Please become familiar with local requirements before removal of wild-land vegetation.
- Tree limbs within 15 feet of a chimney, encroaching on power lines, or touching the house should be removed.
The more continuous and dense the vegetation, the greater the wildfire threat. If this situation is present within your survivable space area, you should “break it up.” This can be done in a variety of ways, depending on the type and arrangement of the vegetation. On the table to the right, look for the vegetation type you have in your yard and follow the recommended practice in the table. This will make your yard more fire safe.
Are there ladder fuels present within the survivable space area? Vegetation is often present at varying heights similar to the rungs of a ladder. Under these conditions, flames from fuels burning at ground level, such as a thick layer of pine needles, can be carried to shrubs that can ignite still higher fuels like tree branches. Vegetation that allows a fire to move from lower growing plants to taller ones are referred to as “ladder fuels.”
The ladder fuel problem can be corrected by providing a separation between the vegetation layers. This can be accomplished by reducing the height of shrubs, removing the lower tree branches, or both. The shrubs could also be removed.
|Fuel Type||Recommended Practice|
|Dried grasses & wildflowers||Once grasses and wildflowers have dried out or “cured”, cut down and remove from the survivable space area.|
|Needles, leaves & branches (on the ground)||Reduce thick layers of pine needles on the ground to a depth of 2 inches. Do not disturb the “duff” layer (dark area at the ground surface where needles are decomposing) if present. Remove dead leaves, twigs, cones, and branches that are within the survivable space area.|
|Shrubs & trees||Remove all dead shrubs and trees from within the defensible space area.|
|Firewood & other combustibles||Locate firewood, LPG tanks, and combustible debris (wood scraps, grass clippings, leaf piles, etc.) at least 30 feet away from any buildings.|