Photo taken on the Camp Fire by a drone in Magalia, California near Indian Drive.
With tens of thousands of homes being destroyed in the last year in California wildfires it should be a very high priority for home builders and local governments to swiftly adopt the practices that can greatly reduce the vulnerability of structures. It is not a given that if a large rapidly-spreading wildfire approaches a house it will ignite and burn to the ground.
Media reports sometimes marvel at how an occasional structure will be spared, and may describe it as miraculous or random. Instead, it is based on science. Some structures are designed, built, and maintained to be less vulnerable than others. The other half of the equation is what is within the home ignition zone — what will become fuel within 100 feet. If there is continuous vegetation or other flammable material in that zone that can carry the fire, especially close to the structure, it stands less chance of survival.
But for now let’s think about the structure itself. There are several useful reference guides for architects, home builders, and zoning boards containing information that can lead to designs and building codes that can help keep a fire from turning into a disaster.
• International Code Council’s International Wildland Urban Interface Code (IWUIC),
• National Fire Protection Association’s Standard for Reducing Structure Ignition Hazards from Wildland Fire (Standard 1144), and
• California Building Code Chapter 7A—Materials and Construction Methods for Exterior Wildfire Exposure.
Headwaters Economics compared the costs of new construction of a typical home vs. one with wildfire resistant standards for a three-bedroom, 2,500-square-foot, single-story, single-family home representative of wildland-urban interface building styles in southwest Montana. Below are excerpts from the article:
We examined costs in four vulnerable components of the home: the roof (including gutters, vents, and eaves), exterior walls (including windows and doors), decks, and near-home landscaping. Overall, the wildfire-resistant construction cost 2% less than the typical construction, with the greatest cost savings resulting from using wildfire-resistant fiber cement siding on exterior walls, in lieu of typical cedar plank siding. While cedar plank siding is typical in the wildland-urban interface of western Montana, fiber cement siding is already a common choice in many regions because of its relative affordability, durability and low maintenance needs. Wildfire-resistant changes to the roof resulted in the largest cost increase, with a 27% increase in gutters, vents, and soffits. The following sections describe the wildfire-resistant mitigations for each component.
Today I was reading an article about how the communities in Northern California are dealing with the risk from wildfire. One item that got my attention was where a “forestry and wildfire specialist” was quoted describing the Fountaingrove area of Santa Rosa which was devastated by the Tubbs Fire in October of last year.
…a housing development in a rural area that had been built following the highest fire safety standards. Vegetation had been cleared as required, and the homes were built of fire-resistant materials.
The article correctly stated that the development had been “reduced to ashes by the Tubbs Fire”.
“How could that have happened?”, I thought. Fire resistant building standards and cleared vegetation? Firefighters know that if those two characteristics can be checked off, a structure has a much better chance of survival. So how did the community get wiped out?
The Fountaingrove community is 4 miles north of the intersection of Highways 101 and 12 in Santa Rosa. The Tubbs Fire, the deadliest of the fires in 2017, burned into the north section of Santa Rosa, including the Fountaingrove area. It killed 22 people, destroyed 5,643 structures, and burned 36,807 acres.
Map showing the perimeters of the Pocket, Tubbs, Nuns, and Atlas Fires. CAL FIRE October 15, 2017.
I would not call Fountaingrove a “rural area”. The thousands of homes there are very tightly packed, as you can see in the satellite photo below taken about five months before the Tubbs Fire.
Satellite photo of an area in Fountaingrove May 17, 2017, before the Tubbs Fire. Google Earth.
The next three photos are all of the same area, showing structures on Fir Ridge Road before and after the Tubbs Fire of October, 2017.
Fir Ridge Road area of Fountaingrove before the Tubbs Fire. Google Maps.Satellite photo of the Fir Ridge Road area in Fountaingrove, June 16, 2017. Google Earth.Satellite photo of the Fir Ridge Road area in Fountaingrove, October 17, 2017. Google Earth.
The photo below was taken before the fire, a few blocks south of the ones above. This home and all others around it burned.
A home on South Ridge Road in Fountaingrove before the Tubbs Fire. Google Maps.
The Fountaingrove area burned in the 1964 Hanley fire. During the 53-year period until the next fire, the 2017 Tubbs Fire, the houses grew back along with a great deal of vegetation. Most of the homes have shrubs in the yards and multiple large trees, often between the houses that are very close together. Some of the structures are partially obscured from aerial photos by limbs hanging over the roofs.
It is difficult to tell if the homes in these photos were constructed of fire resistant materials. But it is clear that other Firewise principles were not being followed.
In a fireprone environment there should be no flammable material within 5 feet of a structure, and in the Home Ignition Zones 5 to 100 feet away, trees need to be 6 to 18 feet apart depending on the distance from the building. If on a slope, these distances have to be increased substantially.
An excellent video that elaborates on these principles has been produced by the NFPA. It points out that the areas in between the trees do not have to be nuked. But to be fire resistant they need to consist of green grass or fire resistant small plants, and should be raked or mowed close to the ground.
If a structure meets these Firewise guidelines, it stands a much better chance of surviving a wildfire. However, if the weather conditions are extreme, such as 60 mph winds and single digit humidity which can lead to spot fires igniting a mile ahead of the main fire, it can be difficult to save a structure.
Most homes are ignited not by the main flaming front of a fire, but from burning embers that land out ahead and start new fires. Likely receptors for these embers are leaves in a gutter, mulch, wooden decks, lawn furniture, attic vents, and accumulations of dead grass, pine needles, leaves, and other flammable material.
When a community is initially planned, the engineers may have done some things right, such as the design of the streets, and water systems. But if everything else is left up to the knowledge and discretion of developer and homeowner, very important principles might be ignored.
Fountaingrove did not meet all of the Firewise guidelines, but the streets were wide, making it easier for large fire trucks to access the structures. The very close spacing of the homes means that if one burns, the radiant heat alone can ignite its neighbor.
Other things to consider in mitigating the wildfire threat include multiple evacuation routes — if one becomes compromised by the fire, another could remain open. Large open spaces without flammable vegetation can serve as safety zones for residents who can’t escape. Backup electrical power sources that can keep pumps running so that community water tanks remain full can ensure firefighters have water at hydrants.
With the warming climate leading to extreme fires and fire seasons that are nearly year round, it is inevitable that deadly fires will strike many wildland-urban interface communities. Under the conditions we have seen in recent years, casually ignoring the threat will lead to more fatalities and property damage. It is not IF a fire will hit a fire prone area, but WHEN. The best solution is to learn to live with and adapt to fire, not ignore it.
Many factors can lead to an area being vulnerable to wildfire, including fire suppression leading to a buildup of vegetation, density of homes like at Fountaingrove, failure of homeowners to use Firewise principles, lack of community standards, insurance companies not understanding the issue, the federal government reducing expenditures for vegetation management and prescribed burning, lawsuits that halt vegetation management projects, and cutting the numbers of firefighters, air tankers, and Type 1 helicopters. When politicians take hold of just one of these issues while ignoring the rest, it can make it impossible to have a rational conversation about adapting to fire.
Discussions need to be thorough and nuanced, not politicized and influenced by industry that profits from using just a single, ill-conceived concept. And zeroing in on one vague term like “raking” and “poor forest management” simply confuse the general public when the complete picture is not illuminated.
Earlier this week Firewise and the National Fire Protection Association released this new video that explains how to reduce the wildfire risks around your home.
When Chief Royal Burnett retired in 1993 his employer’s agency was still called California Department of Forestry (CDF). At that time he was Chief of the Shingletown Battalion of the Shasta-Trinity Ranger Unit in Northern California. Still keeping his hand in the game, Chief Burnett recently spent some time analyzing how the disastrous Carr Fire spread into his town, Redding, California in July of 2018.
“I retained my interest in fire and fuel modeling after retirement”, the Chief said, “and with my fire geek friends I try to keep current.”
Chief Burnett told us that when he left the CDF he was qualified as a Type 2 Incident Commander, Type 1 Operations Section Chief, Type 1 Planning Section Chief, and Fire Behavior Analyst. He has lived Redding, California for 40 years.
The article below that the Chief wrote about his analysis of the Carr Fire is used here with his permission. A version of it has previously appeared at anewscafe.
The Carr Fire burned 229,651 acres and 1,079 residences, about 800 in the county area and the remaining number inside the city limits.
My friends Steve Iverson, Terry Stinson and I spent several days looking at the portion of the Carr Fire burn where it entered the city of Redding. This would be the Urban portion of the Wildland Urban Interface. That part of our town is newer construction, high-end subdivision homes built to California’s “SRA Fire Safe Regulations”. That is, non-flammable roofs, stucco siding, and all the rest of the State’s requirements. How did we lose almost 300 of them in one wildfire?
Royal Burnett
Many of these homes were built right on the edge of the Sacramento River canyon on finger ridges to maximize the view, or on the rim of side draws — anything to maximize the view from the property and capture the afternoon up-canyon wind flow. Most had large concrete patios and some had pools. There were no wooden decks extending over the canyon that I saw.
The Canyon is about ½ mile across where most of the houses burned, with the slope estimated at around 100 percent. The aspect where most of the homes burned is west-facing, meaning it catches the afternoon sun and preheats the forest fuels.
The canyon itself was predominantly filled with manzanita 12 to 15 feet high (75 percent) and the remainder was oak woodland, with scattered ceanothus brush and poison oak . The brush field was approximately 75 years old, having sprouted after Shasta Dam was completed in 1945. Available fuel loading ranged from 1 to 3 tons per acre in the oak woodland to 13 tons per acre in the heavy brush. All herbaceous material was cured and live fuel moisture was approximately 80 percent in manzanita — right at the critical level, which means it will burn as if its a dead fuel, not a live one.
The east side of the Carr Fire near Redding, California. Mapped August 26, 2017. Click to enlarge.
So, we’ve got a canyon filled with tons and tons of very flammable brush on an extremely steep slope with hundreds of very pricey homes perched on the rim, on a day when the temperature was 112 degrees and relative humidity was around 9 percent. To repeat a phrase from the 1960s, this was a “Design For Disaster”. (That was the title of fire training film describing the events of the Bel Air fire in Los Angeles County in 1961). [below]
We can determine how things burned by looking at burn patterns and other forensic evidence. For those who did this for a living its like reading a book. It was easy to figure out why the houses on the rim burned — they were looking right down the barrel of a blowtorch. Even though they had fire resistant construction, many had loaded their patios with flammable lawn furniture, tiki bars and flammable ornamental plants. Palm trees became flaming pillars, shredded bark became the fuse, junipers became napalm bombs.
Under current standards houses are build 6 to an acre; 10 feet to the property line and only 20 feet between houses. Once one house ignited, radiant heat could easily torch the next one.
We followed burned wood fence trails from lot to lot — wooden fences were nothing more than upright piles of kindling wood — and then into some ornamental shrubbery with an understory of shredded bark which torched and set the next house on fire. Then the fire progressed away from the canyon rim, not a wildland fire now, but a series of house fires, each contributing to the ignition of the next one.
We noted several, perhaps as many as a half dozen homes that burned from the ground up. Fire entered the building at the point where the stucco outer wall joined the slab and fire in the decorative bark was forced into the foam insulation and composition board sheeting under the stucco by the wind. Normally a fire in decorative bark is not a problem, it simply smolders. But in this case, where literally every burning ember was starting a spot fire and those spot fires were fanned by 100 mph in-draft wind, those smoldering fires were fanned into open flames which burned the homes. A simple piece of flashing could have prevented some of that loss.
We built homes to a fire resistant standard and then compromised them.
The fire hit Redding on an approximately two-mile front. It spotted across the Sacramento River in several locations and spread rapidly in the canyon, spawning numerous fire whirls. The updrafts caused the convection column to rotate, generating firestorm winds estimated at 140 mph. I’d guess most of the homes that were lost burned in the first hour after the fire crossed the river. The fire and rescue services were overwhelmed.
View from the Sacramento River in Redding north of the Sacramento River Trail Bridge. Google Street View. Click to enlarge.
The city of Redding allowed home construction on canyon rims, places that have proven to be fire traps over the years in almost every community where this construction has been allowed. Houses built in those exposed areas are similar to houses built in a flood zone. Its not a question IF they will burn, the question is When?
These subdivisions had limited egress. In one high-priced gated subdivision there is only one way in or out. Redding planners have seemingly ignored the lessons from past disasters like the Tunnel Fire in Oakland Hills in 1991 where 2,900 homes burned and 25 people died.
The city’s green belts have proven to be nothing but time bombs — fuel choked canyons that are a haven for her homeless. How many fire starts have we had in the canyon below Mercy Hospital, or in Sulfur Creek below Raley’s on Lake Boulevard? The homeless problem has exacerbated the fire problem. The fuels are there, the homeless provide the starts.
Even today, new subdivisions are being built overlooking the burned out canyons, looking across the rim at the ruins of homes burned in the Carr Fire.
The Sacramento River canyon will regrow, and it will be more flammable next time and stumps sprouting brush and noxious weeds will germinate in the burned area. The skeletons of the burned trees will become available fuel. In a couple of years the fuel bed will be more receptive to fire than it was before the Carr Fire.
If we don’t learn from our mistakes we are doomed to repeat them.
Thanks and a tip of the hat go out to Kelly. Typos or errors, report them HERE.
Above: A screen grab from drone footage uploaded October 11 of fire damage in Santa Rosa, California. Since then most of the numbers of lives and homes lost have about doubled. Los Angeles Times.
(Originally published at 1:48 p.m. MDT October 22, 2017)
Even many people who were not physically affected by the recent disastrous wildfires in Northern California are still stunned by what happened beginning the night of October 8 when very strong winds, hurricane force in some locations, pushed incredibly powerful fires through neighborhood after neighborhood.
The latest preliminary data reveals that four of the fires have found places in the list of 20 most destructive fires in California history when measured by the number of structures destroyed. Those four fires, Tubbs, Nuns, Atlas, and Redwood Valley accounted for the destruction of over 7,700 homes, commercial buildings, sheds, garages, and barns. Two of the three largest wildfires have occurred in the last four years.
Those who lost their possessions and homes are going to be hard pressed to find places to live for the next year or two. The state already has a severe housing shortage.
But what comes next in the big picture? People wring their hands and send thoughts and prayers. Is that enough? Most accidents and disasters provide a teaching moment. Will this one be squandered like so many times before after floods, hurricanes, mass shootings, and wildfires? Mentally disabled people accumulate assault rifles and homes are replaced in flood, fire, and hurricane-prone zones. Rinse and repeat.
…The state requires that new buildings in zones deemed by the state to be at high risk of fire be made with fire-resistant materials, such as tile roofs. The state and local governments should also consider requiring older homes and buildings in high-risk zones to be retrofitted.
Unfortunately, urban areas often weren’t included by the state in its designated high-risk zones because, well, nobody expected a wildfire to sweep through a city. State officials are now revising the maps, and the fires around Santa Rosa must surely be a wake-up call that suburbia has to be made more fire resistant.
One of the most serious problems facing firefighters today is the movement of residents into the Wildland/Urban Interface, the WUI. As a wildfire spreads toward flammable structures that are near or in some cases surrounded by burnable vegetation it can be very difficult to protect them. Often as a fire grows in a WUI area containing dozens or hundreds of homes there are not enough firefighters to park a fire engine at every house.
Some structures are easier to protect than others. “Firewise” refers to homes that are designed and maintained to be fire resistant. A few burning embers (that can be transported in the wind for a mile) in most cases will not ignite a home built to withstand fire. It is the other homes, with flammable siding, roofs, and decks, and that have brush or trees providing an efficient path for the fire to spread up to the structure, that is a nightmare for the fire department. In some cases as a fire approaches, this second category of homes will be written off since it may not be possible to save them, even with a fire truck parked in the driveway. Without vegetation clearance of 30 to 100 feet, it can be unsafe for firefighters to remain at the site as an intense fire approaches.
Firefighters at the Gunbarrel Fire west of Cody, WY apply foam and install sprinklers at Goff Creek Lodge, August 26, 2008. Photo by Michael Johnson.
A difficult to defend home is not only a problem for the owner, but it also affects the community. As it burns in a wildfire, it creates huge amounts of radiant and convective heat. Combined with the airborne burning embers put into the air as it burns, it can ignite other homes nearby. If multiple unprepared homes burn, the effects of the conflagration are multiplied making it difficult for even Firewise structures to survive. In addition, unprepared homes suck up more firefighting resources, which can make it difficult or impossible for there to be enough firefighters, crews, engines, and aircraft to suppress the wildland fire — they are often tied up because of some irresponsible residents.
In a perfect world all structures in a WUI would be Firewise. Inevitably, however, a sizeable percentage of homeowners will do nothing to make their structures defensible. There are two ways to encourage, or even force, them to take action before a fire strikes. Zoning laws and insurance companies. Laws can, for example, ban wood shingle roofs, and require vegetation clearances up to 100 feet, as well as other requirements. Many jurisdictions do this.
Insurance companies have an extremely powerful tool at their disposal that is rarely used. According to the NW News Network, at least two companies in Washington and Oregon are refusing to renew the policies for some home owners, or for structures in wildfire prone areas.
Some insurance companies are choosing not to renew policies in wildfire-prone areas of the inland Northwest. That’s sending home owners scrambling to find new coverage for their properties. Northwest-based insurers such as Pemco and Grange Insurance are getting choosier about how much risk they’ll take on. This according to property owners who’ve been dropped recently and posted about their frustrations online.
One customer from Chelan, Washington, complained Pemco refused to renew her homeowners insurance despite 17 years with no claims. The common thread among the non-renewals is location in wildfire country.
Oregon’s insurance regulators looked into this and said some insurers updated their wildfire risk rating models.
“There have been some non-renewals, rate increases, and moratoriums on new business, because updated risk models showed certain areas to be at especially high risk of wildfires,” wrote Jake Sunderland, a Department of Consumer and Business Services spokesman, in an email.
Refusing to write policies in a large area is not the best solution. Some companies will only insure structures after inspecting them to be sure they are Firewise and have defensible space.
