Shake Roof Replacement by July 2014

shakeMountain and foothill homeowners who have wood shake roofs will be required to have new roofs in about two years under an ordinance adopted by the San Bernardino County Board of Supervisors in 2008.

The ordinance requires all roof coverings within Fire Safety Overlays—a.k.a. high-risk fire areas—must be either noncombustible or made of fire retardant material by July 2014.

The County Fire Department is currently identifying homes with shake roofs so owners can be notified by mail and on-site visits about the ordinance, which was implemented to help slow the spread of wildfires in the mountains. County fire is also actively seeking grants to help homeowners cover the cost of replacing shake roofs.

There are three ways a wildfire can cause a home to burn: direct flames, radiant heat, or flying embers.

Out of these, flying embers cause the most house fires, and home roofs are the most susceptible to these airborne cinders.

Shake roofs are extremely vulnerable to flying embers because of their low ignition points. According to a study that looked at about 2,000 California homes burned in wildfires, homes with untreated wood roofs are between 2 to 21 times more likely to be destroyed in a wildfire.

In addition, shake roofs can exacerbate the spread of wildfires because burning wood shakes peel off and become airborne cinders. Roofs aren’t the only factor when it comes to the spread of wildfires.

Homes without adequate vegetation clearance are highly susceptible to fire. State law requires property owners in fire prone communities to have 100 feet of defensible space around their homes. This includes removing all potentially fire-prone vegetation, but not all vegetation, from 30 feet immediately surrounding a property, and creating space between trees and other vegetation for an additional 70 feet around the property.

Fire prone vegetation includes juniper, manzanita and dense thickets of small pine trees that are easily ignitable and give off significant heat when they ignite.

Homeowners should remove needles and leaves from roofs and gutters. Tree limbs should be trimmed at least 10 feet from chimneys, and dead limbs hanging over homes should be removed.

Additionally, homeowners are required to have a chimney outlet with no more than half-inch mesh. Also, homeowners should make sure all roof vents and openings are covered with 1/8th inch screening to restrict the entry of burning embers into the attic space of the house during a firestorm.

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