Building to Survive in Wildfire Country
Don’t get burned: The right materials and details are a start. Landscaping and regular maintenance can help. But even these steps sometimes aren’t enough.
Synopsis: In this special report, contributing writer Scott Gibson takes a look at the devastation left by the 2017 California Wildfires, and addresses whether code requirements saved some dwellings, and whether a review of the building codes is due in the wake of the devastation. He describes the differences between combustible, noncombustible, ignition-resistant, and fire-resistant materials and where they should be used. The article includes an illustration of defensive details to give a home the greatest chance of surviving a wildfire, including recommendations for landscaping, roofs, windows, and doors, and outbuildings.
If you want to build a house in the state of California, you’ll first have to consult a set of maps to find out whether the property is in what’s called a “fire hazard severity zone.” If it is, you’ll be required to follow specific construction guidelines designed to minimize the chance the house will burn down in one of the many wildfires that sweep through the state every year.
These rules, which are part of the California Building Code and are spelled out in the International Wildland-Urban Interface (WUI) Code, address everything from roof coverings and window glass to vent openings on eaves and cornices. In tandem with landscaping practices that keep combustible vegetation safely away from buildings, the WUI (pronounced “woo-ey”) building codes offer a relatively effective way of protecting buildings from fire.
Except wildfires don’t always follow a script.
Last October, what became known as the Wine Country or North Bay fires in Northern California burned over 210,000 acres of land, wiping out more than 8,000 structures and killing at least 42 people. It was the most destructive wildfire event in the state’s history. As state officials at the California Department of Forestry and Fire Protection (Cal Fire) were sorting out those details,…
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My both sides of my family have lived in the San Francisco Bay Area and Northern California since the late 1800s. So forest fires and the kind of urban fires that have regularly damaged the Berkeley hills and lower Marin County are not unfamiliar to me. My mother past away two years to the month prior to the Tubbs fire. The Tubbs fire came to within a typical 5 to 10 minute drive on Santa Rosa's rather heavily travel main boulevards, that provide the only real egress from the neighborhoods west of Highway 101, from the condo she lived in for nearly 30 years. A cousin's daughter and son-in-law lost their home on the East side of 101.
The condo complex my late mother lived in had only one narrow exit, with multiple feeder lanes into it, facing north toward the direction the Tubbs was coming from onto a divided four lane boulevard. Santa Rosa's housing developments since the early 1980s have been rather haphazard and largely developed on the cheap and on what ever former farm and ranch land a developer could get their hands on. These neighborhoods and condo / townhouse developments tend to be self contained, isolated and not directly connected to neighboring residential neighborhoods down on the flat lands of Santa Rosa.
If I recall correctly from Bay Area news agencies, the Tubbs fire burst into Santa Rosa from out of the northeasterly direction moving south-southwest more or less and at a rate of 300' to 500' per second at its worst; animals were found charred to death where they stood.
In fire conditions like that, delaying to evacuate to put out an ember with a bucket of water was certain suicide. Many who died in California's fires last Fall had the cruel fate of lack of time, from the time they knew of they were in danger, to even get out of their garages let alone any distance from their homes.
David Shew, staff chief for planning and risk analysis at Cal Fire, considers embers to be the most dangerous, accounting for 70% to 90% of the houses lost to wildfires.
Authorities called for Mandatory Evacuation. An ember would land on someones property and start a small fire that could be put out with a bucket of water. Fire trucks were spread out. They could not detect a fire until the house was almost fully involved. This is why you would have one house destroyed while the rest of the neighborhood was untouched. The point is, the home owners left their homes unprotected when they could have easily saved them.