HOME HARDENING BASICS

National Interagency Fire Center - https://www.youtube.com/watch?v=w5sVqcSa_9E

BACKGROUND

“It’s all about the embers”  Frank Frievalt, Fire Chief of Mammoth Lakes Fire Protection District, March 2020

Home hardening is to build homes in a way that is more fire resistant. Hardening a home to withstand wildland fire exposure does not have to be costly, but it does require an understanding of the exposures your home will experience when threatened by a wildfire.

Home and building loss during wildfires occur as a result of some part of the building igniting from one or more of the three basic wildfire exposures: 1) embers, 2) radiant heat, and 3) direct flame contact.

 

Embers cause the majority of wildfire home ignition by directly igniting your home or igniting vegetation or materials on or near your home that results in flames touching your house or a high heat (radiant heat) exposure that may break glass in a window. Should embers land on or near your house, they accumulate (like hail) and can easily ignite the plants and mulch near your home, dry leaves, or lawn furniture.

They also land on the roof, deck, or porch and depending on the condition of each may find a gap to enter the house or can catch accumulated dry leaves on fire. Very commonly embers enter the home or attic through a vent or open window. When embers enter the home or attic, they can easily ignite the contents of the house and the home will burn from the inside out. When embers enter the house directly there is often little damage to the surrounding vegetation and many are left puzzled as to what caused the home to burn.

 

Homes survive wildfire through a combination of:

1) careful landscape selection, placement, and maintenance

2) awareness and management of combustible materials on the property (e.g. leaf litter or lawn furniture) during your fire season

3) incorporation of fire and ember resistant construction materials, installation details and maintenance.

 

Ember-resistant construction relies on awareness of seemingly small details that can make your home vulnerable to embers, in addition to building with appropriate materials, and regular home and property maintenance.

University of California Cooperative Extension - Fire in California. https://ucanr.edu/sites/fire/Prepare/Building/

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  SOME BASIC STEPS TO GET STARTED PROTECTING YOUR HOME

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START WITH YOUR HOME AND WORK OUTWARD

Remove and clear away flammable debris and vegetation touching the house

  • Keep pine needles and leaves off your roof and out of your gutters

  • Remove windblown piles of leaves next to your house and under decks

  • Cut back all plants, bushes, hedges, and trees within 5 feet of your house

  • Cover the 0-5 foot perimeter around your house with materials that can’t burn

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OPEN UP YOUR YARD CLOSE TO YOUR HOUSE (5-30 FEET)

  • Fewer and smaller plants are desirable in this “donut” fairly close to your house

  • Carefully consider what trees, bushes, and other plants you really want near the house

  • Remove everything else flammable in this donut

  • If you heat with wood, keep your wood pile well away from your house

  • If you store building materials or have a wood storage shed, move them away

  • Prune branches from mature trees 6 to 10 feet above the ground

  • Remove brush beneath tree canopies

    Reduce the fuel load beyond 30 feet from your house

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THINK ABOUT YOUR ROOF

  • If the outer material is not tile, steel, or other “class A” materials, replace it

  • A new fire-resistant roof is obviously costly, but critical to home safety

  • Inspect and maintain your roof annually to avoid openings for embers

  • If your roof has gutters, install metal covers that reduce collection of leaves

 Seal the holes

  • Carefully inspect your siding, windows, doors, and eaves for any holes or gaps

  • Repair and caulk any openings that might allow an ember to lodge or enter

 Screen your vents

  • Vents into attics, crawlspaces, and living spaces should shield against embers

  • Steel mesh screens with 1/16” or 1/8” openings should cover vents

  • Baffles can help prevent entry of embers

  • Metal covers or shutters can block vents when not needed