Each year, wildfire burns millions of acres of land. Research around home destruction vs. home survival in wildfires point to embers and small flames as the main way that the majority of homes ignite in wildfires. Embers are burning pieces of airborne wood and/or vegetation that can be carried more than a mile through the wind can cause spot fires and ignite homes, debris and other objects.
There are methods for homeowners to prepare their homes to withstand ember attacks and minimize the likelihood of flames or surface fire touching the home or any attachments. Experiments, models and post-fire studies have shown homes ignite due to the condition of the home and everything around it, up to 200’ from the foundation. This is called the Home Ignition Zone (HIZ).
The concept of the HIZ was developed in the late 1990s, following some breakthrough experimental research into how homes ignite due to the effects of radiant heat. The HIZ is divided into three zones; Immediate, Intermediate, and Extended.
1) Immediate Zone: The home and the area 0-5 feet from the furthest attached exterior point of the home; defined as a non-combustible area. This is the most important zone to take immediate action on, as it is the most vulnerable to embers. START WITH THE HOUSE ITSELF then move into the landscaping section of the Immediate Zone.
• Clean roofs and gutters of dead leaves, debris and pine needles that could catch embers. • Replace or repair any loose or missing shingles or roof tiles to prevent ember penetration. • Reduce embers that could pass through vents in the eaves by installing 1/8 inch metal mesh screening. • Clean debris from exterior attic vents and install 1/8 inch metal mesh screening to reduce embers. • Repair or replace damaged or loose window screens and any broken windows Screen or box-in areas below patios and decks with wire mesh to prevent debris and combustible materials from accumulating. • Move any flammable material away from wall exteriors – mulch, flammable plants, leaves and needles, firewood piles – anything that can burn. Remove anything stored underneath decks or porches.
2) Intermediate Zone: 5-30 feet from the furthest exterior point of the home. Landscaping/hardscaping- employing careful landscaping or creating breaks that can help influence and decrease fire behavior.
• Clear vegetation from under large stationary propane tanks. • Create fuel breaks with driveways, walkways/paths, patios, and decks. • Keep lawns and native grasses mowed to a height of four inches. • Remove ladder fuels (vegetation under trees) so a surface fire cannot reach the crowns. Prune trees up to six to ten feet from the ground; for shorter trees do not exceed 1/3 of the overall tree height. • Space trees to have a minimum of eighteen feet between crowns with the distance increasing with the percentage of slope. • Tree placement should be planned to ensure the mature canopy is no closer than 10 feet to the edge of the structure. • Tree and shrubs in this zone should be limited to small clusters of a few each to break up the continuity of the vegetation across the landscape.
3) Extended Zone: 30-100 feet, out to 200 feet. Landscaping – the goal here is not to eliminate fire but to interrupt fire’s path and keep flames smaller and on the ground.
• Dispose of heavy accumulations of ground litter/debris. • Remove dead plant and tree material. • Remove small conifers growing between mature trees. • Remove vegetation adjacent to storage sheds or other outbuildings within this area. • Trees 30 to 60 feet from the home should have at least 12 feet between canopy tops. • Trees 60 to 100 feet from the home should have at least 6 feet between the canopy tops.
Other important safety tips:
Wildfire safety: • Remove pine needles and dry leaves from around your home. Keep woodpiles at least 30 feet from your home. • Know your local evacuation plan. Plan ahead by practicing two ways out of your neighborhood. You should know the evacuation route and plan a place where you will go. • If you are told to evacuate, do so immediately. If you wait until the last minute, the roads may have heavy traffic. Blowing embers and debris from the fire may make it hard to see. • Stay informed. Listen to the TV/radio broadcasts for current weather and emergency instructions. Sign up to receive local emergency alerts and warnings on both your home phone and cellphone. • Make sure everyone in your family knows your meeting place ahead of time. Let your family and friends who do not live in your area know your meeting place. • Keep your car fueled and keep an emergency supply bag in your car. Back your car into the garage or park it in an open space facing the direction of escape.
Outdoor fire safety: • Move the grill at least 10 feet away from siding, decking, and other things that can catch fire. • Stay with the grill the entire time you are cooking. • Use long-handled barbecue tools when cooking on the grill. • Use a metal screen over wood-burning fires to keep sparks from floating out. • Turn off or put out fires before you leave the backyard. • Build campfires at least 15 feet away from tent walls, shrubs or other things that burn. • The best way to stay safe from fireworks is to not use them. |