Is Your Home Defensible ? Will you be a victim of nature?

Are You at Risk?
 
If you aren't sure whether your house is at risk from natural disasters, check with your local fire marshal, building official, city engineer, or planning and zoning administrator. They can tell you whether you are in a hazard area. Also, they usually can tell you how to protect yourself and your house and property from damage. It is never a bad idea to ask an InterNACHI inspector whether your roof is in need of repair during your next scheduled inspection. Protection can involve a variety of changes to your house and property which that can vary in complexity and cost. You may be able to make some types of changes yourself.




But complicated or large-scale changes and those that affect the structure of your house or its electrical wiring and plumbing should be carried out only by a professional contractor licensed to work in your state, county or city. One example is fire protection, accomplished by replacing flammable roofing materials with fire-resistant materials. This is something that most homeowners would probably hire a contractor to do.
  
Replacing Your Roof
  
The age of your roof is usually the major factor in determining when to replace it. Most roofs last many years, if properly installed, and often can be repaired rather than replaced. An isolated leak usually can be repaired. The average life expectancy of a typical residential roof is 15 to 20 years. Water damage to a home’s interior or overhangs is commonly caused by leaks from a single weathered portion of the roof, poorly installed flashing, or from around chimneys and skylights. These problems do not necessarily mean you need a new roof.
 
Fire-Resistant Materials
 
Some roofing materials, including asphalt shingles, and especially wood shakes, are less resistant to fire than others. When wildfires and brush fires spread to houses, it is often because burning branches, leaves, and other debris buoyed by the heated air and carried by the wind fall onto roofs. If the roof of your house is covered with wood or asphalt shingles, you should consider replacing them with fire-resistant materials. You can replace your existing roofing materials with slate, terra cotta or other types of tile, or standing-seam metal roofing. Replacing roofing materials is difficult and dangerous work. Unless you are skilled in roofing and have all the necessary tools and equipment, you will probably want to hire a roofing contractor to do the work. Also, a roofing contractor can advise you on the relative advantages and disadvantages of various fire-resistant roofing materials.

---

Defensible space refers to the area surrounding a building that is mitigated to protect it from wildfires. Along with the quality of a building’s roofing material, adequate defensible space is one of the most important factors in determining a building’s ability to survive a wildfire. Inspectors should know enough about defensible space to educate their clients, particularly in fire-prone regions. 
 
Defensible space performs the following functions:

1. Ideally, a carefully maintained defensible space will not contain enough fuel to allow a wildfire to reach a house. Even if the space is breached, the fire will have been slowed and weakened, helping firefighters to defend the house.
2. A defensible space provides an accessible area for fire trucks to park and firefighters to work during a structure fire.
3. If there is a pond near a burning house, it can be used to replenish a fire truck’s water supply. The perimeter of the pond should be thinned of trees and brush sufficiently so that firefighters can access it.

The size requirements for defensible space vary by jurisdiction because the potential for wildfires varies by region. Buildings in forested areas of the Southwest need a much larger protective space than in New Jersey, for instance. As of 2006, California state law mandates a minimum of 100 feet of defensible space for houses in rural locations. Trees and shrubs surrounding a house should be trimmed and spaced apart a safe distance from one another. Chainsaws can be used to remove trees and branches, pruning shears to trim plants, and rakes for removing pine needles and other ground-level combustibles. Trees that are very close to the house should be removed because this is where fire-prevention is most critical. Vegetation can be plentiful towards the perimeter of the space if it is green and pruned.

Colorado State University divides defensible space into three categories in the following manner:
Zone 1:  The first 15 feet from a home should be devoid of all flammable vegetation. Firewood and other flammable materials should not be stored in this region.

Zone 2:  This area of fuel reduction should extend from Zone 1 outward to between 75 to 125 feet from the structure. Trees and large shrubs should be no less than 10 feet apart, especially in steep terrain. Trees must also be pruned to a height of 10 feet from the ground, and any “ladder fuels” (vegetation with vertical continuity) removed from the base of the trees. Grass, trees and shrubs in this region should be green and adequately spaced. Pine needles, dead leaves, branches, dead or dying vegetation and other flammable debris on the ground should be removed whenever they appear.
Zone 3:  This region of traditional forest management is of no particular size, although it normally extends to the property limits. More trees are permitted here than in Zone 2, although their health and vigor should be maintained.

---

Precautions That Inspectors Can Pass on to Their Clients

• Homeowners should obey all environmental protection laws while creating and maintaining defensible spaces. In particular, removal of vegetation should not interfere with the well-being of endangered species, air and water quality, or archaeologically significant resources. Homeowners may need to obtain a permit to cut down trees over a certain size, depending on local jurisdictions.

• Vegetation removal can cause soil erosion, especially in steep terrain. InterNACHI advises that in areas that are prone to wildfire and soil erosion, it can be helpful to replace highly flammable plants and trees with less-flammable alternatives.
  

In summary, buildings can be spared from wildfire damage through the removal of surrounding flammable vegetation. Defensible spaces are critical in hot, dry, forested regions, although their presence is recommended everywhere.

Used by permission by Nick Gromicko and Kenton Shepard
nachi.org
 

---