Facing Fire

When the June 2007 Angora Fire burned its way into the residential streets of South Lake Tahoe, Calif., firefighters were ready.

The neighborhoods, unfortunately, were not.

As it always does, Cal Fire—the California Department of Forestry and Fire Protection—threw everything it had at the fast-moving forest fire. “Cal Fire does not have a ‘let-burn' or ‘fire-management' philosophy, period,” explains California Fire Marshal Kate Dargan. “Our policy is to immediately extinguish all fires, and we apply all resources—air tankers, ground resources, firefighters, bulldozers, helicopters—I mean, we will put everything on a fire to keep it as small as possible, every time.”

But many houses in the threatened communities were built with wood siding, wood decks, and even wood-shake roofs. Adding to the difficulties, the houses sat in heavily wooded lots—many of them thick with underbrush or littered with fallen branches and pine needles.

To limit silt erosion into the nearby lake, points out California Building Industry Association (CBIA) official Bob Raymer, “they have effectively allowed the use of four different toppings for your land—and all four of them are burnable. I mean, up there, for some reason, they allowed the use of pine needles as ground cover.” Pine needles had also accumulated on roofs and in gutters—ready tinder for any wind-blown spark.

Once in the neighborhood, the fire spread rapidly from house to house. Even with help—from local fire departments, “hot shot” firefighting teams from other states, and U.S. Forest Service crews—Cal Fire could not stop the fire from destroying 254 homes. “In these conflagration fires,” says Dargan, “where dozens or hundreds of homes are burning in a short period of time, there are not enough fire engines to protect every structure.”

In big fires such as the Angora fire, that practical limit forces firefighters to make tough tactical choices on the ground. Hour by hour, crews have to balance their own personal danger against the chances of saving a house. Says Chief Brad Harris of Cal Fire's Nevada-Yuba-Placer unit north of Lake Tahoe, “The community expects that firefighters are going to risk all to protect their home. And there are certain risks that we will take. But we will also make wise decisions. We are not in the business of trading firefighter lives for property. If it's going to cost a firefighter's life to save a property where we don't have a likelihood of success, it's time to move on and protect one that we can protect.”

Because big fires can cause major destruction, fireground commanders occasionally catch heat for being too cautious.

FATAL TRAGEDY: Investigators examine a destroyed fire engine at the site of a deadly “burnover” near Cabazon, Calif., where five Forest Service firefighters died in a vain attempt to save one isolated house during the November 2006 Esperanza fire.

After the 2002 Rodeo-Chediski fire near Show Low, Ariz., for example, local firefighters castigated Forest Service incident commanders for hanging back from neighborhood defense. Linden, Ariz., firefighter Gary Holdcroft spoke for many when he wrote in his 2004 book about the fire, Walking Through the Ashes, “I have nothing but respect for the men and women who did the actual work. My gripe is with the people who think homes and neighborhoods and towns are expendable.”

As the huge fire bore down on Pinedale and Clay Springs, Ariz., Holdcroft says, “every piece of firefighting equipment was pulled out, on the orders of the Fire Service, and sent to a field five miles away. When a crew from Clay Springs [and eventually Linden] broke ranks from the Fire Service to try to defend their homes, they were branded as renegades.” In 2006, showing a reporter a photo of dozens of engines parked at a staging area, Pinedale firefighter Charlie Brown—one of the few who went back to town against orders—asked, “You see masses of people in there. Why did they run with this equipment and leave us?”

Some local firefighters lost their own homes in that disaster. But as officials point out, no firefighters or civilians died in what turned out to be Arizona's biggest-ever wildfire. And while losing a house because of cautious firefighting is unfortunate, the cost of erring in the opposite direction can be tragic. Just last year, for example, five Forest Service firefighters operating under Cal Fire command during November's Esperanza Fire, near Cabazon, Calif., were burned to death doing “structure protection” on an isolated hilltop house. Situated at the top of a long dry wash and surrounded by tinder-dry chaparral brush, the spot became an inescapable firetrap when hot 60-mph Santa Ana winds, funneling through the canyon, pushed the flame front over the lip of the hill and around the octagon-shaped building. As the fire incinerated their engine and gutted the house and its outbuildings, there was no safe haven for the firefighters on the knoll.

Fire agencies are still coming to terms with the Esperanza tragedy. At a minimum, Cal Fire and Forest Service officials say, they plan to place renewed emphasis on risk assessment training. But more important may be the longer-term shift that is taking place in California, and across the U.S., in fire prevention policies for the “wildland-urban interface.” The firefighter's dilemma—whether to hunker down and defend a home or retreat for the sake of safety—is much less difficult when basic preventive measures are in place to boost the odds that a house will survive on its own if an active defense is too dangerous to be practical or if the fire has outstripped the available firefighting resources. Says Chief Harris, “We have to remember, the property owner has a role and responsibility in the defense of their home. The fire departments around the nation can only do so much. We need the defensible spaces, we need fire-resistant construction to help us to protect these homes.”

California has the worst wildfire conditions, not just in the U.S., but in the world, observes Dargan. Wildfire can threaten homes in any state; but in California, the risk is endemic. Says Harris, “On any given day, somewhere in the state, we're doing structure protection against a wildfire.”

TOTAL LOSS: A homeowner views the ashes of his home at an Arizona RV park after 2002's Rodeo-Chediski fire. Controversy persists about fire commanders' decisions in that disaster.

The state has been studying and analyzing the wildfire hazard for years—at least, says Dargan, since the Oakland Hills fire destroyed more than 3,000 dwellings back in 1991. But until now, the research has paid few dividends. Recent attempts to modify California building codes were lagging, says CBIA's Raymer, until the Schwarzenegger administration took over—and Democrat Dargan, herself a 30-year veteran of wildland firefighting operations, was appointed state fire marshal.

“Once Kate got on the scene, she revitalized this whole thing,” says Raymer. “She put us in a room and said, ‘Come out with a standard or you don't get to come out.' And when you have the fire service, the building officials, the product manufacturers, and the builders in the same room knowing that they have to keep working until we come up with something—well, within a year we had put that puppy to bed.” New code rules for ignition-resistant house construction and landscaping, written in as Chapter 7A of Title 24, the statewide California building code, will start taking effect on the first of January 2008.

BEYOND SAVING: A home burns to the ground during the 2006 Esperanza fire. When wildfires outpace firefighter resources, say experts, homes that ignite are typically destroyed.

California's beefed-up strategy has three prongs:

Hazard assessment. The surrounding terrain, the vegetation cover, the local climate, and the area's fire history all influence the underlying fire hazard at a given homesite. Contractors for California have been working to assess the danger at street level and to create interactive digital maps of the whole state that display the fire hazard rating for every address and every potential building site. At any given spot, the toughness of code-required ignition-resistance measures will depend on the site's hazard (“moderate,” “high,” or “very high”). The latest versions of county-level hazard maps are now available for download at www.fire.ca.gov/wildland_zones.php. Or, people can search for specific addresses on the statewide interactive map posted at fire center.berkeley.edu/fhsz/.

Materials testing. California has also created new laboratory tests to assess the ignition resistance of exterior building products. The test protocols (available for download at www.fire.ca.gov/wildland_codes.php), put various building components through severe simulated fire exposure:

These tests are unlike the usual flame-spread tests and one-hour or two-hour, firerating tests so familiar in the construction industry, notes Dargan. But she says there's a reason for that. “We're introducing a concept and definition of ‘ignition resistant' into the code for the first time, as opposed to ‘fire resistant' or ‘non-combustible,'” she says. A one-hour fire rating on a house wall is fine for ordinary situations, she explains; if it takes an hour for fire in one house to burn its way into the house next door, that's plenty of time for firefighters to respond. But in large-scale fires where there aren't enough fire crews to go around, any house that catches fire is likely to burn to the ground. So California's goal is to stop homes from catching fire at all—and that's what the tests aim to ensure.

At first, concedes Dargan, there may not be many products around that can pass the tough new tests. But CBIA's Raymer gives Dargan credit for allowing the code committee to provide builders with practical ways to comply in the meantime. For every material or component that is regulated, explains Raymer, the new rules provide a prescriptive compliance path as well as a test method. In the case of windows, for example, the prescriptive alternative simply specifies dual-pane glazing with at least one layer of tempered glass (dual-pane glazing, even without tempered glass, has been demonstrated to make a big difference in window performance). “It's not going to be onerous from a cost perspective,” says Raymer. “Those product lines are already out there.”

Building rules. The third prong of California's program is the code rules themselves. These amount to just a few pages, published as an amendment to Title 24, and, like the other rules, available on the Internet at www.fire.ca.gov/wildland_codes.php. The rules address the key vulnerabilities in conventional house construction:

DANCES WITH FLAMES: Firefighters rush to contain a “spot fire” caused by flaming embers blown ahead of the main fire front during last summer's Angora fire in Lake Tahoe, Calif. In windy weather, wildfires often jump forward threatening homes as well as dry vegetation.

For “state responsibility” areas in California—the parts of the state where Cal Fire is in charge of fire protection—the new code rules will go into effect Jan. 1. In “local responsibility” areas, where town or county fire departments are in charge, there's a grace period: The new fire hazard maps are still undergoing local review, so enforcement of the new codes will be delayed until June, to give local authorities time to digest the new information and make plans for the change.

If new regs make relatively small demands on builders, perhaps that's because house details are less important than site management. Thinning trees, trimming brush, and clearing ground are the best way to hold fire at bay—and in California, towns and counties require it. Across the country, advocates for the NFPA's Firewise program (see “Rules for Living on the Wild Edge,” page 113) are encouraging voluntary efforts to make whole developments fire-resistant, starting at the planning stage.

Bob Rhea, a wildfire mitigation specialist with the Florida Division of Forestry, has some success stories to point to. In some dry years, fires in overgrown pine plantations or scrublands have burned dozens or hundreds of Florida homes. But developers are catching on: “I've got two communities near Port St. Joe that became Fire-wise before there was a single resident or a single home built,” says Rhea.

Besides the recommended road access, hydrant, landscaping, and building details, explains Rhea, the neighborhoods have covenants that allow crews to clear or burn brush to reduce fuel loads near homes. “They burn on a rotational basis,” says Rhea. “When you go to closing, it's presented to you: ‘This is a Firewise community. We burn here. And if you don't like it, you better think about not buying here.' Because there is no tolerance for people yelling and screaming about smoke.”

Washington state developer Chris Heftel is another believer. When he started his River Bluff Ranch community near Spokane, Wash., Heftel says, “I took over a forested mountain-top and realized that a catastrophic wildfire might be the only scenario that could wipe me out financially—because if the whole mountain burned up, it would be a long time before anybody would want to buy a home-site there. You just have to look at it as an asset to maximize.”

Heftel first thinned out ice-damaged and beetle-killed deadwood and overgrown brush: “That was expensive, but now I have a healthy forest.” Limited clear-cutting later for roads, homesites, and views paid for itself, he says: “That was a positive cash-flow exercise because of the marketable timber.” Now, says Heftel, “we're into more of a maintenance mode—we catch a few things here, a few things there, and that is more of a break-even operation.”

Like the Florida communities Rhea touts, Heftel's development carries covenants requiring homeowners to maintain a lean landscape over the long haul. The agreements are written to make local fire agencies a beneficiary, so that if homeowners don't keep up with their obligations, fire officials can enforce the rules.

“Covenants are free,” reasons Heftel. “And we don't lose any buyers because of our Firewise covenants, but we have, I think, appealed to some people because of them.”

For sure, says Heftel, the proactive approach is the most cost-effective. “Prevention is just a tiny fraction of the cost of retrofitting after the fact. And that's just a tiny fraction of the cost of trying to fight a fire in conditions that never should have been allowed in the first place. So to me, the common sense thing is to never do a development, and never build a house, that doesn't incorporate Firewise planning into it from the get-go.”

California is the only state that has adopted statewide codes addressing wildfire home-ignition risks. But California's not the only place where wildfire is a threat. Most Western states, and many areas east of the Mississippi, also experience wildfires that threaten or destroy housing. Fire services and forestry departments where the risks are high have been pushing local governments to adopt rules for development and construction in the wildland-urban interface (or WUI); groups are also working to educate builders and developers about ignition-resistant strategies, in hopes that the private sector will move to voluntarily address the dangers of home construction in wild country.

The central clearinghouse for wildfire education is the Firewise program (www.firewise.org), anchored by the National Fire Protection Association (NFPA) and supported by a wide range of organizations including the U.S. Forest Service. Firewise offers training materials, books, videos, and other informational material, and organizes classes and workshops for fire services, building departments, developers, and builders.

NFPA has also developed two formal standards targeting the problem: NFPA 1141, “Standard for Fire Protection Infrastructure for Land Development in Suburban and Rural Areas,” and NFPA 1144, “Standard for Reducing Structure Ignition Hazards from Wildland Fire.” Available for purchase online at www.nfpa.org, both documents have been substantially revised for their 2008 editions. NFPA 1144, which used to contain some provisions dealing with developer issues such as street layout and water supply, now focuses strictly on house and landscape components and details. Its systematic organization makes it suitable as a comprehensive checklist for designing, building, or inspecting houses and homesites, from ridge to foundation and out to the edge of the property.

Keeping their distance from deadly heat, firefighters hose down a burning home.

The International Code Council (ICC) has addressed the WUI problem with a stand-alone code document, the International Wildland-Urban Interface Code, or IWUIC, separate from either the International Building Code (IBC) or the International Residential Code (IRC). The IWUIC defines requirements for buildings and landscapes very similar to the measures laid out in NFPA 1144, along with the administrative provisions typical of other ICC codes. The International WUI Code is already in force in a handful of Western local jurisdictions.

All three documents—the California building code, the NFPA standards, and the International WUI Code—are comprehensive, in that they cover all the major elements of a structure's exterior and its building site. But on a technical level, the requirements aren't much of a hurdle. Michele Steinberg, an NFPA administrator who works with the NFPA 1144 standard-writing committee and the Firewise program, used to work on hurricane issues with the insurance industry's Institute for Business and Home Safety (IBHS). Compared to hurricane issues, says Steinberg, wildfire resistance is a piece of cake: “You don't have to think about structure. You put Class A shingles on, you put double-pane windows in—this is not crazy stuff. It's readily available materials and practical methods.”

1) - EAST BAY HILLS FIRE

Oakland, Calif., October 1991

Damage: About 1,500 acres burned, more than 3,000 homes destroyed, 25 deaths

2) - CALIFORNIA WILDFIRES

October 2007 (still burning)

Damage: 500,000 acres, more than 2,000 homes destroyed, 7 deaths

3) - CEDAR FIRE

San Diego County, Calif. - October 2003

Damage: 280,278 acres burned, 2,232 homes destroyed, 14 deaths

4) - VALENTINE, DAWES, AND SIOUX FIRES

Nebraska - July 2006

Damage: 70,000 acres burned, 14 homes destroyed

5) - TEXAS-OKLAHOMA RANGE FIRES

November 2005–April 2006

Damage: 5 million acres burned, 700 homes destroyed, 11 deaths

6) - BIG TURNAROUND AND BUGABOO FIRES

Georgia-Florida - April 2007 (still burning)

Damage: 450,000 acres burned, 24 structures destroyed

7) - FLORIDA WILDFIRES

Spring and summer 1998

Damage: 2,300 separate fires, 500,000 acres burned, 300 homes destroyed

8) - PINE BARRENS FIRE

New Jersey - May 2007

Damage: 14,080 acres burned, 5 homes destroyed

To understand Firewise building and developing ideas, it helps to take a lesson from Forest Service research physicist Jack Cohen. A former wilderness firefighter himself, Cohen has spent many years examining why and how wildfires destroy houses.

From a forester's perspective, says Cohen, it's a mistake to put out every wildfire. Fire is a fact of nature that helps create the natural landscape we love, he explains; and in the long run, wildfire can't be prevented. But that doesn't mean we need to let our houses burn, too. Speaking like the scientist he is, Cohen argues, “This is simply a combustion ignition problem. Ignition requires three things: fuel, oxygen, and heat. If the house and its surroundings meet those requirements for combustion, then it ignites and burns. And if it doesn't meet those requirements for combustion, it doesn't burn. And in the second case, the interface problem goes away.”

Cohen pioneered the concept of the “home-ignition zone,” which he defines as the house itself, plus its immediate surroundings out to about 100 feet (or in very dangerous terrain, as far as 200 feet). Within that buffer area, he says, it's possible to maintain conditions that will make the house largely immune to ignition from wildfire—allowing foresters to decide how to handle the wildfire itself based on ecological concerns rather than property loss risks.

HOLDING THE LINE: Firefighters scrape away flammable ground debris for a “scratch line” near another house at the Lake Tahoe Angora fire. Once homes catch fire, they become a primary source of the fire's spread through the populated area.

Cohen's research—including test fires on large forest stands as well as extensive post-fire investigations in burned-over neighborhoods—indicates that big, hot “crown fires” aren't the main threat to homes. Those raging-hot blazes in the treetops are fed by fast-burning fine fuels such as needles and twigs, he says, and flame fronts pass by in just minutes. As long as the fire's not too close—no closer than 100 feet, as a rule—the radiant heat subsides too soon to set a wood wall on fire. (Windows are another matter, however. Single-glazed windows may crack and fall out from the heat long before a wall would ignite—that's why codes call for double-glazing.)

So in wildfire country, keeping the woods 100 feet distant from the house provides a good safety zone against the crown fire. “The streets, the houses themselves, driveways, utility easements, all break up the tree canopy,” says Cohen. “It doesn't take very much fragmentation of the canopies to stop the crown fire from spreading at that location. So what I find when I go into a community after a fire is that the crown fires, almost without exception, aren't spreading through the community.”

But that still leaves a second threat: low-intensity, creeping ground fire that approaches houses slowly after the main flame front has passed by. To stop those slowly encroaching flames, Cohen says, property owners have to remove the fuel they feed on. You do that by keeping large trees away from the house at least 30 feet, and thinning the trees and branches to separate tree crowns at least 10 feet apart. “Ladder fuels”—low trees and shrubs that let fire climb from the ground into the trees—have to be removed. Closer to the house, the landscaping should be “lean, clean, and green”—with no shrubs against the building.

NO-IGNITION ZONE: A handful of house and landscape details can make all the difference for homes threatened by wildfire, according to fire science experts. Roof, vent, window, and deck details can toughen a house against flame and embers, while brush clearing and pruning within a 100-foot radius can hold super-hot “crown fires” at bay.

But there's a third way that wildfires attack a home: wind-blown burning embers, or “firebrands.” Says California Fire Marshal Kate Dargan, “We believe the majority of structure ignitions are caused by embers.” On a windy day, these burning twigs can travel as far as a mile from a burning forest, although they might also come from as close as the house next door. Like a blizzard of strike-anywhere matches, the embers pile up in corners and drift under decks. If the spot where they settle out has a fuel source, the embers will start a fire. A broken window will let them into the house where they can ignite curtains or furniture. A low deck with dry leaves under it or a stack of logs against a house gives the firebrands a ready ally for attacking the home. Here is where ignition-resistant building details really come into play: To survive the attack by flying embers, the house needs its Class A roof, its ignition-resistant deck, and its debris-free gutters.

Saving homes from burning requires attention to all three sources of ignition. And that means paying attention to the whole problem: the house, its landscape, and the surrounding area. Says Dargan, “There is a set of responsibilities that travel around. The folks who are approving the site and permitting the structure need to be responsible for making sure that good site design is in place; the builders for constructing the building according to good code; the homeowners for maintaining it; and the firefighters for assessing risk and weighing benefit.”