Learn about the two most vulnerable parts of a home, the "home ignition zone" for wildfires and defensible space.

Much of what is known about protecting homes from wildland fire is based on the work of Jack Cohen, a Fire Research Scientist at the U.S. Forest Service Fire Lab in Missoula, Montana. Cohen has been studying wildfires for almost 30 years. His research and field investigations support some interesting explanations for home losses associated with wildland/urban interface fires. Cohen has found that most wildland/urban interface homes are lost because of ignitions associated with the two most vulnerable parts of a home:

1. The roof
2. The area immediately surrounding the structure

Cohen's research results indicate that home ignitions usually occur over relatively short distances — tens of yards, not hundreds of feet from little things associated with either:

• Fire brands landing on and around the structure, or
• Flames from slow-moving, low-intensity surface fires contacting flammable portions of the structure.

This means that the homeowner can play a significant role in reducing home losses from wildfires by reducing fuels and through careful landscaping in what Cohen calls the "home ignition zone," an area that extends outward from the home 100 to 200 feet in all directions. Research has shown that the home ignition zone principally determines the potential for home ignitions during severe wildfires.

Case studies indicate that the most critical area is a zone of "defensible space" within 30 feet of the structure.

Maintaining a lean, clean and green landscape within 30 feet of a structure can make a significant difference in whether it survives a wildfire. The important thing is that action must be taken before wildfire threatens.

• Lean: Small amounts of flammable vegetation
• Clean: No accumulations of dead vegetation
• Green: Plants are healthy and green; lawn is well irrigated

Reducing fuel within the defensible space means creating a landscape that breaks up the continuity of brush and other vegetation that could bring wildfire in contact with any flammable portion of the structure.

 This may involve:

• Eliminating any flammable vegetation in contact with the structure.
• Thinning out trees and shrubs so there is 10 to 15 feet between the tree crowns.
• Pruning tree limbs to a height of 6 to 10 feet.
• Replacing highly flammable landscape material with plant materials having a higher water content.
• Replacing flammable mulch adjacent to the structure with gravel or rock.
• Eliminating "ladder fuels" near the structure that might carry a surface fire to the roof or eaves.

Fire is a natural part of our Florida ecosystems. It is not a matter of if we are going to have wildfires, but when we will have wildfires and at what intensity. Homeowners must assume a major role in wildfire protection by taking action to reduce the ignitability of their homes before the threat of a wildfire.