Stopping a fire with a blanket

fire blanket vehicle fire
Screengrab from Bridgehill video.

You may have seen videos floating around recently of a fire resistant blanket being used to control a vehicle fire. It looks pretty simple — two people grab the corners of the blanket and pull it over the burning  vehicle. Deprived of oxygen, the fire appears to be extinguished after just a few seconds. It makes sense, of course. No oxygen, no fire. But I assume if the blanket were quickly removed, there could be enough residual heat to reignite the fire as soon as oxygen was reintroduced.

The video below demonstrates how it works, using a product sold by Bridgehill, a company headquartered in Larvik, Norway.

Prices for the blanket, which they claim can be reused up to 50 times, start at $2,422 at Darley.

A California company takes advantage of the same principle, oxygen starvation, when using their version of a fire blanket to slow or stop the spread of a vegetation fire at a structure. Fire Break Solutions makes a 15-foot wide product that can be rolled out over grass or, the company claims, “low to medium brush.” It is made from interwoven strips of fire resistant fabric that are a couple of inches apart, leaving holes in between the strips. The side closest to the structure being protected has a solid skirt several feet wide. The intent is that the fire would burn into the area covered by the blanket and burn slowly underneath. By the time it gets to the solid fabric the fire would be much less intense and would slowly self extinguish.

The company advises that the edges should be weighted down with dirt or rocks. It comes in various lengths, with the 100-foot version priced at about $6,000.

Obviously, burning embers from a far-away fire could land directly on or adjacent to the house, so the home would need to be designed and built paying attention to the fire resistant characteristics of the roof, vents, siding, doors, windows, foundation, eaves, and decks. Fire Break says there should be no flammable material between the blanket and the house. If just outside of the fire blanket are tall grass, brush, or a continuous canopy of trees, no 15-foot wide fire blanket is going to save a structure.

The video below shows how it is deployed.

In the video below the Flame Brake covers half of a bed of fuel which looks like excelsior — fine curled wood shavings.

FireBreak also sells the Emberella fire blanket, which is a solid piece of fabric intended to cover a vehicle, hedges, or small structures. Their video shows it being tested.

Emberella fire blanket structure fire
Emberella fire blanket being tested, screenshot from the video. Fire Brake Solutions image.

Thanks and a tip of the hat go out to Dave.

New California law requires seller of home to disclose vulnerability to wildfires

EIler Fire Home
One of the homes that survived the Eiler Fire in northern California, August, 2014. Photo by Bill Gabbert.

Beginning January 1 in California the seller of a home in a designated high fire area built before 2010 must disclose to the buyer conditions that make the home vulnerable to wildfires.

The seller must provide documentation stating that the property is in compliance with local laws pertaining to defensible spaces or local vegetation management laws. If there is no such local law, the seller shall provide documentation of compliance with state law, assuming the seller obtained such documentation within six months prior to entering into the transaction. But if neither of the above, the seller and the buyer must enter into a written agreement in which the buyer agrees to obtain documentation of compliance with defensible space or a local vegetation management ordinance after close.

Here are the details from the legislation:


Disclosures re Home Hardening

Beginning January 1, 2020, if a seller, after completion of construction, has obtained a final inspection report regarding compliance with, among other things, home hardening laws (Gov’t Code 51182 and 51189*), the seller shall provide to the buyer a copy of that report or information on where a copy of the report may be obtained.

Beginning January 1, 2021, this law requires for properties located in high or very high fire hazard severity zones for homes built before 2010, delivery of a notice to include the following three items:

1. A statutory disclosure that includes information on how to fire harden homes as follows:

“This home is located in a high or very high fire hazard severity zone and this home was built before the implementation of the Wildfire Urban Interface building codes which help to fire harden a home. To better protect your home from wildfire, you might need to consider improvements. Information on fire hardening, including current building standards and information on minimum annual vegetation management standards to protect homes from wildfires, can be obtained on the internet website http://www.readyforwildfire.org.”

2. Disclosure of a list of features that may make the home vulnerable to wildfire and flying embers if the seller is aware. The list includes, among other things, untreated wood shingles, combustible landscaping within five feet of the home, and single pane glass windows.

3. On or after July 1, 2025, a list of low-cost retrofits re home hardening (listed pursuant to Section 51189 of the Government Code*). The notice shall disclose which listed retrofits, if any, that have been completed during the time that the seller has owned the property.

Potential point of sale compliance requirements re defensible space or local vegetation management laws

Beginning July 1, 2021 seller of property in high or very high fire hazard zones shall provide documentation to the buyer stating that the property is in compliance with laws pertaining to state law defensible spaces (Public Resources Code 4291**) or local vegetation management ordinances, or in certain cases the buyer and seller will agree that the buyer is to obtain the documentation after close as follows

1. If there is a local ordinance requiring the seller to comply with state law governing defensible spaces (PRC 4291**) or a local vegetation management ordinance, the seller shall provide the buyer with: 1) a copy of the documentation of such compliance, and 2) information on the local agency from which a copy of that documentation may be obtained.

2. But If no such local ordinance exists, and the seller has obtained an inspection from a state, local or other government agency or qualified nonprofit which provides an inspection with documentation for the property, the seller shall provide the buyer with: 1) the documentation of the inspection if obtained within six months prior to entering into a transaction to sell the real property and 2) information on the local agency from which a copy of that documentation may be obtained.

3. If seller hasn’t obtained documentation of compliance per 1 or 2 above, then the seller and buyer shall enter into a written agreement stating that the buyer agrees to: a) obtain documentation of compliance per the local ordinance or b) if there is no such local ordinance, the buyer shall, within one year, obtain documentation of compliance as long as there is a state, local or other government agency or qualified nonprofit which provides an inspection with documentation of compliance for the property.

This law also requires the California Office of Emergency Services (Cal OES) to enter into a joint powers agreement with the Department of Forestry and Fire Protection (Cal FIRE) to administer a comprehensive wildfire mitigation and assistance program to encourage cost-effective structure hardening and facilitate vegetation management, contingent upon appropriation by the Legislature.

Officials disagree on responsibility for evacuation planning in Marin County, California

Marin County fire history 1917-2020
Marin County fire history 1917-2020. The blue areas were all prior to 1980. NIFC map.

Many residents and government officials in Marin County recognize the importance of evacuation planning, but there is no agreement on which agency has the responsibility. In March voters approved a parcel tax that would raise about $19 million each year for the newly formed Marin Wildfire Prevention Authority (WPA), but the county’s Civil Grand Jury ruled in December that the agency’s plans do not adequately address the issue.

Marin County map
Marin County, outlined in red. (Google)

From the Marin Independent Journal:

Part of that funding will go toward studying evacuation routes, creating evacuation maps and clearing vegetation along narrow Marin roads. But the agency does not have the authority or the funding to take on infrastructure projects that could create safer roads for people fleeing wildfires, the grand jury said.

“The grand jury is concerned that Marin’s public may have a false sense of security regarding evacuation routes, thinking that all issues relating to the matter will be handled by the new government agency,” the report says.

While Marin County fire Chief Jason Weber agreed that the wildfire authority doesn’t have the funding to take on road infrastructure projects, he said the agency is taking the initial step in addressing Marin’s evacuation safety problem.

Marin County, population 258,826, is bordered on the west by the Pacific Ocean and stretches from the Golden Gate Bridge north to Bodega Bay and east to Novato and San Pablo Bay.

Evacuation planning will likely point out a need for road infrastructure projects, for which the WPA does not have funding. The Transportation Authority of Marin, or TAM, is the only agency in the county with access to funding and authority over countywide transportation projects. The grand jury recommended that a representative from TAM serve as a non-voting member of the WPA.

Marin County evacuation choke points
Marin County Civil Grand Jury, Wildfire Preparedness: A New Approach, Appendix C, April 25, 2019.

Fire officials in Marin County have identified “choke points” where residents are likely to get caught in congestion when evacuating from wildfires. Since many of those run through multiple jurisdictions, the grand jury said TAM should serve as the coordinating agency but TAM officials “continue to deny that the agency has any role or responsibility for considering evacuation needs in its transportation projects.”

Community infrastructure and planning was one of the six categories of actions Wildfire Today pointed out in April, 2019 that must be taken to reduce the impact of wildfires on communities. That category includes:

  • Distance to nearby structures
  • Evacuation capability and planning
  • Safety zones where residents can shelter in place
  • Road and driveway width, wide enough for large fire trucks
  • Turnarounds at the end of roads
  • Signage, and
  • Emergency water supply.

The other five categories that need to be considered in fire-prone communities are home spacing/lot size; envelope of the structure itself; home ignition zone; wildland-urban interface; and fire codes.

Data for structures destroyed by wildfires in each state

structures burned Almeda Drive Fire Phoenix Talent Oregon
Devastation from the Almeda Drive Fire in the area of Phoenix and Talent in southern Oregon. Screenshot from video shot by Jackson County on September 8, 2020.

The traditional way — and the easiest way — to compare wildfire seasons is the number of acres burned. That figure is fairly straightforward and reliable, at least for data within the last 35 years; before 1984 the data is questionable.

But blackened acres does not tell the whole story about the effects of fires on humans. A 50,000-acre fire in a northwestern California wilderness area has fewer direct impacts on the population than, for instance, the 3,200-acre Almeda Fire that destroyed 2,357 residences in Southern Oregon a few months ago.

Top most destructive wildfires in the United States
Top most destructive wildfires in the United States. Headwaters Economics.

Headwaters Economics has built a user friendly interactive data base of the number of structures, by state, destroyed by wildfires from 2005 to 2020. It presumably includes all structures, including back yard sheds, other outbuildings, commercial buildings, and residences.

Here are three screenshots, examples for the entire U.S., Colorado, and Montana.

Top most destructive wildfires Montana
Top most destructive wildfires in Montana. Headwaters Economics.
Top most destructive wildfires Colorado
Top most destructive wildfires in Colorado. Headwaters Economics.

The best way to prevent homes from being destroyed in a wildfire is not clear cutting or prescribed burning a forest, it is the homeowner reducing flammable material in the Home Ignition Zone. This includes spacing the crowns of trees at least 18 feet apart that are within 30 feet of the home, 12 feet apart at 30 to 60 feet, and 6 feet apart at 60 to 100 feet. The envelope of the structure itself must be fire resistant, including the roof, vents, siding, doors, windows, foundation, fences, eaves, and decks. A FEMA publication (13 MB) has excellent detailed recommendations. Headwaters Economics found that the cost of building a fire-resistant home is about the same as a standard home. When implemented, Chapter 7A of the California Building Code, regulates these features.

firewise wildfire risk home tree spacing
Firewise vegetation clearance recommendations. NFPA.

For more information: Six things that need to be done to protect fire-prone communities.

And, Community destruction during extreme wildfires is a home ignition problem. Here is an excerpt from the article written by Jack Cohen and Dave Strohmaier:

Uncontrollable extreme wildfires are inevitable; however, by reducing home ignition potential within the Home Ignition Zone we can create ignition resistant homes and communities. Thus, community wildfire risk should be defined as a home ignition problem, not a wildfire control problem. Unfortunately, protecting communities from wildfire by reducing home ignition potential runs counter to established orthodoxy.

Bill introduced to promote prescribed fire intends to reduce fire risk

It would appropriate $300M annually for the federal land management agencies’ prescribed fire programs. But are there other ways to reduce fire risk?

September 24, 2020 | 8:10 a.m. MDT

American Elk prescribed fire Wind Cave National Park
A firefighter ignites the American Elk prescribed fire in Wind Cave National Park, October 20, 2010. Photo by Bill Gabbert.

A bill has been introduced in the U.S. Senate that would make large sums of money available to increase the number of acres treated with prescribed fire (also known as controlled burns).

It has been fashionable during the last two years to blame “forest management” for the large, devastating wildfires that have burned thousands of homes in California. According to a 2015 report by the Congressional Research Service the federal government manages 46 percent of the land in California. The California Department of Forestry and Fire Protection manages or has fire protection responsibility for about 30 percent.

Research conducted in 2019 to identify barriers to conducting prescribed fires found that in the 11 western states the primary reasons cited were lack of adequate capacity and funding, along with a need for greater leadership direction and incentives. Barriers related to policy requirements tended to be significant only in specific locations or situations, such as smoke regulations in the Pacific Northwest or protecting specific threatened and endangered species.

The National Prescribed Fire Act of 2020, Senate Bill 4625, which was introduced last week by Senator Ron Wyden of Oregon and two cosponsors, would help address the capacity issue by appropriating $300 million for both the Forest Service and the Department of the Interior (DOI) to plan, prepare, and conduct controlled burns on federal, state, and private lands. It would also provide $10 million for controlled burns on county, state and private land that are at high risk of burning in a wildfire. Additionally, the bill establishes an incentive program that would provide $100,000 to a State, county, and Federal agency for any controlled burns larger than 50,000 acres. (Summary and text of the bill)

In order to carry out the projects, the legislation would establish a workforce development program at the Forest Service and Department of the Interior to develop, train, and hire prescribed fire practitioners, and creates employment programs for Tribes, veterans, women, and those formerly incarcerated.

In an effort to address air quality control barriers,  the bill “Requires state air quality agencies to use current laws and regulations to allow larger controlled burns, and give states more flexibility in winter months to conduct controlled burns that reduce catastrophic smoke events in the summer.” The legislation will allow some prescribed fire projects larger than 1,000 acres to be exempt from air quality regulations.


Our Take

Appropriating more funds and hiring additional personnel for conducting prescribed fires could definitely result in more acres treated. If the bill passes, it would be a large step in the right direction. It is notable that the bill specifically mentions hiring those who were formerly incarcerated. Those who served time for non-violent offenses often deserve another chance, especially if they learned the firefighting trade on a state or county inmate fire crew.

There are many benefits of prescribed fires, including more control over the adverse health effects of smoke, improving forest health, and returning fire to dependent ecosystems.

But it gets complicated when prescribed fire is expected to “…help prevent the blistering and destructive infernos destroying homes, businesses and livelihoods”, as cited in a release issued last week by the Senate Committee on Energy and Natural Resources.

One provision of the bill is poorly worded and is confusing. In Section 102 it is either saying that no later than September 30, 2022 every unit of the USFS, FWS, NPS, and BIA must conduct a prescribed fire larger than 100 acres, possibly only applying to units west of the 100th meridian. Or, it might be interpreted as meaning each unit larger than 100 acres must conduct at least one prescribed fire. But either way it is ridiculous and arbitrary. Some 100-acre units might never be suitable for prescribed fire. Planning to use fire as a tool is based on science and the determination that treating an area with fire is PRESCRIBED in order to accomplish a number of specific objectives, not well-meaning but possibly detrimental legislation.

Scenario #1, Moderate fire conditions

There is no doubt that if a wildfire is spreading under moderate conditions of fuels and weather (especially wind), when the blaze moves into an area previously visited by any kind of fire the rate of spread, intensity, and resistance to control will decrease. Firefighters will have a better chance of stopping it at that location. The size of that earlier fire footprint will be a factor in the effectiveness of stopping the entire fire, since the wildfire may burn through, around, or over it by spotting. The availability of firefighting resources to quickly take advantage of what may be a temporary reduction in intensity is also critical. Unless the prescribed fire occurred within the last year or so there is usually adequate fuel to carry a fire (such as grass, leaves, or dead and down woody fuel) depending on the vegetation type and time of year. It is much like using fire retardant dropped by air tankers. Under ideal conditions, the viscous liquid will slow the spread long enough for firefighters on the ground to move in and put out the fire in that area. If those resources are not available, the blaze may eventually burn through or around the retardant.

Scenario #2, Extreme fire conditions

The wildfires that burn hundreds or thousands of homes usually occur during extreme conditions. What the most disastrous fires have in common is drought, low fuel moisture, low relative humidity, and most importantly, strong wind. In the last few weeks in California and Oregon we have seen blazes under those conditions spread for dozens of miles in 24 hours.

Rich McCrea, the Fire Behavior Analyst on the recent North Complex near Quincy, CA, said the wind on September 8 pushed the fire right through areas in forests that had been clear cut, running 30 miles in about 18 hours.

We can’t log our way out of the fire problem.

Sheltering from the Creek Fire at the Mammoth Pool Reservoir
Burning embers lofted by the Creek Fire are seen as people are sheltering at the Mammoth Pool Reservoir Boat Launch, Sept. 5, 2020 in Northern California. Photo by Cameron Colombero, via Mike Ikahihifo.

On September 8, 2020 the Almeda Drive Fire burned 3,200 acres in Southern Oregon — it was not a huge fire, but there were huge losses. The 40 to 45 mph wind aligned with the Interstate 5 corridor as it burned like a blowtorch for 8 miles, starting north of Ashland and tearing through the cities of Talent and Phoenix. Approximately 2,357 structures were destroyed — but not all by a massive flaming front. Burning embers carried up to thousands of feet by the fire landed in receptive fuels near or on some structures, setting them alight.

structures burned Almeda Drive Fire Phoenix Talent Oregon
A portion of the Almeda Drive Fire in the area of Phoenix and Talent in southern Oregon. Screenshot from video shot by Jackson County on September 8, 2020.

What can be done to reduce fire losses?

Jack Cohen is a retired U.S. Forest Service Research fire scientist who has spent years determining how structures ignite during extreme wildfires. In a September 21, 2020 article he wrote for Wildfire Today with Dave Strohmaier, they addressed how homes ignite during extreme wildfires.

“Surprisingly, research has shown that home ignitions during extreme wildfires result from conditions local to a home. A home’s ignition vulnerabilities in relation to nearby burning materials within 100 feet principally determine home ignitions. This area of a home and its immediate surroundings is called the home ignition zone (HIZ). Typically, lofted burning embers initiate ignitions within the HIZ – to homes directly and nearby flammables leading to homes. Although an intense wildfire can loft firebrands more than one-half mile to start fires, the minuscule local conditions where the burning embers land and accumulate determine ignitions. Importantly, most home destruction during extreme wildfires occurs hours after the wildfire has ceased intense burning near the community; the residential fuels – homes, other structures, and vegetation – continue fire spread within the community.

“Uncontrollable extreme wildfires are inevitable, however, by reducing home ignition potential within the HIZ we can create ignition resistant homes and communities. Thus, community wildfire risk should be defined as a home ignition problem, not a wildfire control problem.”

"Community wildfire risk should be defined as a home ignition problem, not a wildfire control problem." Jack Cohen and Dave Strohmaier.

Again, prescribed fire has many benefits to forests and ecosystems, and Congress would be doing the right thing to substantially increase its funding.

But in order to “…help prevent the blistering and destructive infernos destroying homes, businesses and livelihoods”, we need to think outside the box — look at where the actual problem presents itself. The HIZ.

I asked Mr. Cohen for his reaction to the proposed legislation that he and I were not aware of when the September 21 article was published.

“Ignition resistant homes, and collectively communities, can be readily created by eliminating and reducing ignition vulnerabilities within the HIZ,” Mr. Cohen wrote in an email. “This enables the prevention of wildland-urban fire disasters without necessarily controlling extreme wildfires. Ironically, ignition resistant homes and communities can facilitate appropriate ecological fire management using prescribed burning. The potential destruction of homes from escaped prescribed burns is arguably a principal obstacle for restoring fire as an appropriate ecological factor. Therefore, it is unlikely that ecologically significant prescribed burning at landscape scales will occur without ignition resistant homes and communities.”

Here are some suggestions that could be considered for funding along with an enhanced prescribed fire program.

  • Provide grants to homeowners that are in areas with high risk from wildland fires. Pay a portion of the costs of improvements or retrofits to structures and the nearby vegetation to make the property more fire resistant. This could include the cost of removing some of the trees in order to have the crowns at least 18 feet apart if they are within 30 feet of the structures — many homeowners can’t afford the cost of complete tree removal.
  • Cities and counties could establish systems and procedures for property owners to easily dispose of the vegetation and debris they remove.
  • Hire crews that can physically help property owners reduce the fuels near their homes when it would be difficult for them to do it themselves.
  • Provide grants to cities and counties to improve evacuation capability and planning, to create community safety zones for sheltering as a fire approaches, and to build or improve emergency water supplies to be used by firefighters.

Our article “Six things that need to be done to protect fire-prone communities” has even more ideas.

Community destruction during extreme wildfires is a home ignition problem

burned homes
US Forest Service photo

By Jack Cohen and Dave Strohmaier

We must abandon our expectation that we can suppress 100% of wildfires and reject the false narrative that community protection requires wildfire control. Community wildfire disasters have only occurred during extreme conditions when high wind speed, low relative humidity, and flammable vegetation result in high fire intensities, rapid fire growth rates, and showers of burning embers (firebrands) starting new fires. Fire agencies primarily use wildfire suppression tactics for protecting communities from wildfires. But as we see from current extreme wildfire conditions in California, Oregon, and Washington, fire suppression can quickly become overwhelmed and ineffective.

Wildfires, and thus extreme wildfires, are inevitable. Does that mean wildland-urban (WU) fire disasters are inevitable as well? Absolutely not! WU fire research has shown that homeowners can create ignition resistant homes to prevent community wildfire disasters. How can that be possible?

aerial photo Paradise Camp Fire
Paradise, California, off Herb Lane near Skyway in Paradise. From Butte County drone mapping project. November, 2018.

Recall the destruction in Paradise, CA, during the extreme 2018 Camp Fire. Most of the totally destroyed homes in Paradise were surrounded by unconsumed tree canopies. Although many journalists and public officials believe this outcome was unusual, the pattern of unconsumed vegetation adjacent to and surrounding total home destruction is typical of WU fire disasters. In 2020 we see the same patterns of home destruction and adjacent unconsumed vegetation in photos from Malden, WA, and Phoenix, Talent, Blue River, and Mill City OR. Home destruction with adjacent unconsumed shrub and tree vegetation indicates the following:

burned home
U.S. Forest Service photo.
  • High intensity wildfire does not continuously spread through a residential area as a tsunami or flood of flame.
  • Unconsumed shrub and tree canopies adjacent to homes do not produce high intensity flames that ignite the homes; ignitions can only be from burning embers and low intensity surface fires.
  • The “big flames” of high intensity wildfires are not causing total home destruction.
structures burned Almeda Fire Phoenix Talent Oregon
The Almeda Drive Fire in the area of Phoenix and Talent in southern Oregon. Image by Jackson County, September 8, 2020.

Surprisingly, research has shown that home ignitions during extreme wildfires result from conditions local to a home. A home’s ignition vulnerabilities in relation to nearby burning materials within 100 feet principally determine home ignitions. This area of a home and its immediate surroundings is called the home ignition zone (HIZ). Typically, lofted burning embers initiate ignitions within the HIZ – to homes directly and nearby flammables leading to homes. Although an intense wildfire can loft firebrands more than one-half mile to start fires, the minuscule local conditions where the burning embers land and accumulate determine ignitions. Importantly, most home destruction during extreme wildfires occurs hours after the wildfire has ceased intense burning near the community; the residential fuels – homes, other structures, and vegetation – continue fire spread within the community.

Uncontrollable extreme wildfires are inevitable; however, by reducing home ignition potential within the HIZ we can create ignition resistant homes and communities. Thus, community wildfire risk should be defined as a home ignition problem, not a wildfire control problem. Unfortunately, protecting communities from wildfire by reducing home ignition potential runs counter to established orthodoxy.

There are good reasons to do “fuel treatments” for ecological and commercial objectives. But the greatest fuel treatment effect on wildfire behavior is within the fuel treatment area; fuel treatments do not stop extreme wildfires. So let’s call a spade a spade and not pretend that many, or even most fuel treatment projects actually reduce home ignition potential during extreme wildfires. Because local conditions determine home ignitions, the most effective “fuel treatment” addressing community wildfire risk reduces home ignition potential within HIZs and the community. Wildfires, exacerbated by climate change, will occur. Community destruction during extreme wildfires will continue as long as wildfire suppression remains the primary approach for community protection. Conducting the same ineffective strategy and tactics expecting different results will continue to be a recipe for disaster when it comes to protecting homes from extreme wildfire.

To make this shift, land managers, elected officials, and members of the public must question some of our most deeply ingrained assumptions regarding fire. For the sake of fiscal responsibility, scientific integrity, and effective outcomes, it’s high time we abandon the tired and disingenuous policies of our century-old all-out war on wildfire and fuel treatments conducted under the guise of protecting communities. Instead, let’s focus on mitigating WU fire risk where ignitions are determined – within the home ignition zone.

For further information:


Jack Cohen, PhD, retired US Forest Service Research fire scientist determined how structures ignite during extreme wildfires, created the home ignition zone concept, and co-developed NFPA Firewise USA.

Dave Strohmaier is Missoula County Commissioner. He previously worked for both the Bureau of Land Management and US Forest Service in fire management, and has published two books on the subject of wildfire in the West.