Exterior Fire Sprinklers Saved 188 Properties – Wet homes don’t burn

As renowned fire scientist Jack Cohen has said repeatedly, the wildland fire problem is a home ignition problem, not a wildfire control problem. Cohen has been trying to help fire agencies understand this since 1999. Unfortunately, they have shown little interest. We are hoping with the recent wildfire tragedy in Paradise, California, attitudes will change.

But private citizens don’t have to wait.

There are a number of proven strategies and retrofits that can be implemented easily to homes and communities now. One is the installation of exterior fire sprinklers.

The story of the resistance to exterior fire sprinklers illuminates a crippling dichotomy between the structural fire protection and wildland fire communities. But first, the good news. Exterior fire sprinklers systems work, are affordable, and can be easily installed.

Exterior fire sprinklers in action in Australia. From Platypus Fire Pty Ltd.

The Sprinklers Can Save Homes

The effectiveness of exterior fire sprinklers was proven during the 2007 wind-driven Ham Lake Fire in Cook County, Minnesota. In 2001, exterior sprinklers had been installed on 188 properties, including homes and a number of resorts. All 188 properties survived. More than 100 neighboring properties were destroyed.

The 2007 Ham Lake Fire, looking west from Gunflint Lake Rd. on May 9, 2007. From Dan Baumann.

It’s Affordable

The cost of the Cook County program was covered by a FEMA hazard mitigation grant. The program was finished on time and on budget by Wildfire Protection Systems (WPS), costing $764,255. Minnesota U.S. Senator Amy Klobuchar credited the program with saving over $42 million in property value. The grant paid 75% of the cost of the sprinklers. Individual property owners covered the balance. With a ready water source, a sprinkler system installation from WPS for an average home can cost between $10,000 to $15,000.

The sprinklers were so successful that a $3 million FEMA pre-disaster mitigation grant was awarded in 2008 to install additional wildfire sprinkler systems throughout Cook County. In 2013, another grant was awarded to install the systems in two additional counties, including properties with low-water resources. FEMA pre-disaster grants have also been used in Big Bear and Idyllwild, California to retrofit homes with non-flammable roofing and ember-resistant attic vents.

Canadians have successfully utilized exterior sprinklers too, with the implementation of portable sprinkler kits placed in the path of wildfires. The kits can tap into nearby water sources, pools, or local water tanks. These kits have protected over $2 billion in property value over the past 20 years in Canada, according to Morris Douglas, a retired advisor to various Ministries of Natural Resources.

Exterior sprinklers work by creating an environment that extinguishes embers (spotting firebrands) that are the primary cause of building ignition. The sprinklers do this by 1) hydrating potential fuels, thus making them less susceptible to ignition, 2) increasing humidity, and 3) creating a cooler microclimate around the home.

The impact of the high-severity Ham Lake Fire.

Exterior sprinklers saved this property, along with surrounding vegetation, during the Ham Lake Fire. The sprinklers not only hydrate the structures, but also nearby vegetation.


When we have suggested exterior fire sprinklers as an innovative way to protect homes from wildfires in California, we’ve typically encountered scoffs. The common reasons given for rejecting the idea:

– Too expensive (guesses as high as $60,000 have been mentioned).
– Wind will blow the water away from the house.
– Water pressure disappears during catastrophic fire events, disabling sprinklers.
– The power goes off during catastrophic events, disabling water pumps.
– People won’t have time to turn the sprinklers on.

All of these doubts are either incorrect or can be easily addressed.

Affordable. As mentioned above, grants can be obtained that can reduce the cost of a professionally installed system for an individual homeowner with a ready source of water to around $3,000. Without a grant, homeowners can install the systems themselves for considerably less than the professional price.

Wind. Yes, strong winds will deflect the water spray. However, despite 20-25 mph wind gusts during the Ham Lake Fire, the installed sprinkler systems worked well. Inspections during the fire found that although the rooftop sprinklers were the least effective when impacted by wind, other placements performed as expected. Some innovative solutions, such as WEEDS (see below) actually use wind to distribute the water.

Independent Systems. During a catastrophic fire event, critical infrastructure often collapses. Electrical power goes out and water pressure drops. This is why an exterior fire sprinkler system needs to be independent, or off the grid. A propane, gas, or diesel water pump (about $1,000) must be connected to a dependable water source (e.g. pool, 10,000 gallon water tank, or lake as is the case in Cook County). A 10,000 gal water tank costs about $6,000, so that adds to the system’s total price, but considering the cost of losing a home it’s a smart investment. A neighborhood could invest in a larger water tank that could serve a number of homes.

Time. When people are awakened in the middle of the night and see smoke everywhere, panic can set in. It’s difficult enough to evacuate, much less run outside and turn on the sprinklers. Unless the system is automated or can be activated by a switch on the way out (this adds to the cost), time is definitely an issue. However, it is not an excuse to dismiss the possibility of using exterior sprinklers.

Extra time can be found if communities can get their emergency alert systems up to speed, and trained CERT volunteers serve as support personnel (they do not evacuate). These fire volunteers can activate the systems, extinguish ember-caused spot fires, and help those who are stranded. During wind-driven, catastrophic wildfires there will never be enough professional emergency personnel available to do the job. Communities should consider picking up the slack.

Protecting their own Neighborhood

The effectiveness of expanding the ranks of emergency fire personnel with volunteers was demonstrated by Jeff and Cathy Moore in Chico during the Camp Fire. They stayed behind and were able to save their home and others around them. They doused surrounding vegetation and extinguished spot fires throughout their neighborhood. Their home also had exterior sprinklers. It definitely helped that they also had proper defensible space, but embers move right on through. In fact, open space just makes it easier for embers to reach the house.

Being a fire volunteer and staying behind when the evacuation call goes out is not a casual decision. Being confronted with the power, the noise, the smoke, and the swirling embers of a wildland fire can instill panic in the most seasoned wildland firefighter. This is why only those who are specially trained should stay behind to defend a community.

Cathy and Jeff Moore stand in front of their home after the Camp Fire in Chico, Calif. They were able to save their neighborhood from the Camp Fire. Note exterior sprinklers on the roof.From Mason Trinca, The Washington Post.

Stories Abound

Many other residents have taken it upon themselves to retrofit their own homes with exterior sprinkler systems. Under-eave misters on the Conniry/Beasley home played a critical role in allowing the structure to survive the 2003 Cedar Fire in San Diego County. The home was located in a canyon where many homes and lives were lost to the flames. You can read their story here.

There are a number of other options becoming available as well. M-Bar Technologies offers an objective analysis of one approach that uses the wind to help distribute the water spray, the Wind-Enabled Ember Dousing System (WEEDS). The system is credited with saving another home threatened by the 2003 Cedar Fire.

Wildfire Protection Systems has begun installing exterior sprinkler systems in Payson, Arizona and Mill Valley, California.

During and After. Most homes ignite by embers landing on flammable surfaces and creating spot fires. This home, burned in Lake Arrowhead, California, could have been saved with exterior sprinklers. We don’t know the full story here, but we are hoping something happened that prevented the folks present during the first photo from extinguishing the fire on the steps. From Mark Thiessen, National Geographic.

Why so resistant?

Over the last few decades, two firefighting traditions have collided with the expansion of homes into the wildland urban interface (the WUI). The result has been a severe case of cognitive dissonance over how to deal with the fire threat.

Municipal fire departments were originally organized to deal with structural fires, but their primary job often becomes saving lives. This is one reason why interior fire sprinklers have become a required part of public buildings. Interior sprinklers have been life savers, for both firefighters and civilians, in burning structures – they provide the environment and the time needed for people to escape. They are not, however, generally designed to save structures, especially considering the damage caused by the water.

The primary goal of wildland firefighters, on the other hand, is to suppress wildfires fueled by vegetation.

As increasing numbers of developments have pushed into wildlands, creating the infamous wildland urban interface, the response of fire agencies has depended upon their particular traditions and experiences. Wildfire agencies like the U.S. Forest Service and Cal Fire see the problem as one of too much vegetation. Consequently, they push for additional habitat clearance operations, fuel breaks, and prescribed burns. Municipal fire departments have focused on improving building codes (e.g. non-flammable roofing, ember-resistant vents) and more recently, defensible space.

However, as the increasing number of fatalities and destroyed communities from wildfires demonstrates, these measures are proving inadequate. The issue is that the physics of ember movement and the actual cause of homes igniting (by embers) has yet to be fully integrated into how fire agencies approach the wildfire problem, or as Cohen says, the home ignition problem.

Ironically, even though it is becoming well known that embers ignite and ultimately lead to the destruction of communities a mile or more ahead of the fire front (despite defensible space, fuel breaks, and habitat clearance projects), wildfire agencies and politicians keep focusing on the big flames produced by wildland trees and shrubs. The old municipal/wildland firefighting paradigms have become blinding. The failure to see the real problem is an example of how cognitive dissonance can have disastrous consequences.

How can we keep embers at bay? Current firefighting paradigms need to be replaced with ones based on how the expanding wildland urban interface and a warming climate are changing the environment. Only then will the scoffing over exterior sprinklers end and public policy begin to properly address the home ignition problem.

For additional recommendations on how to improve the fire safety of your home and community, please see our page on Protecting Your Home. Also please see our full set of recommendations to policy makers on how to reduce wildfire losses in California.




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24 Responses to Exterior Fire Sprinklers Saved 188 Properties – Wet homes don’t burn

  1. Karen Berk says:

    I tried to contact M-bar Technologies last spring, but received no reply. I then emailed someone on a local fire council in Kensington, CA (part of San Diego). I haven’t heard back from her since the first reply. I would like to install sprinklers but have no idea who does that in the San Diego area. Do you have any contacts?

    • Hi Karen. We are publishing a document soon that will detail exterior fire sprinklers. We’ll send you a copy via a response here. Or you can send us an email and request one: naturalist@californiachaparral.org

      • Karen Berk says:

        I’ve read all this information before. As I am 65 and my husband 72, I am afraid DIY is beyond our capabilities. We are in the process of designing a pool to use for recreation and as a future water source for a sprinkler/eave system. Hopefully someone will start building such systems before we have another devastating fire.

      • Richard Snyder says:

        Yes, my system is more of an area system but will be available where ever you need it. The system will be completely self contained. You could pull water from a pool or add a tank. I am trying to finalize some legal paperwork. Hoping to have the prototype done next month. Once the paperwork is done I can take deposits on systems. Since we are located in Northern California, a system in San Diego wouldn’t be a problem. It could also be customized to you specific needs.

        On Fri, Sep 27, 2019, 4:14 PM The California Chaparral Institute Blog wrote:

        > Karen Berk commented: “I’ve read all this information before. As I am 65 > and my husband 72, I am afraid DIY is beyond our capabilities. We are in > the process of designing a pool to use for recreation and as a future water > source for a sprinkler/eave system. Hopefully someone w” >

  2. James Bowers says:

    I’m all for this even though I don’t think it would have saved any homes in Paradise. I had sprinklers on my roof and running in my yard. When I left my house was dripping wet but was still incinerated. The two houses closest to me did had no suppression and survived untouched. When I rebuild I will have a better system God forbid this happens again. I will also stay to fight it next time with my own water supply. I’ve also said since the 2008 fire that the town should have had industrial spinklers on the the tree tops drawing from lake oroville in a time like this. People just rolled their eyes at me.

    • Thank you James. Yes, fire is indeed capricious. It exploits the weakest link. We’ve faced the same eye rolling with our proposals as well. Meanwhile the same policies keep failing.

      Very sorry you lost your home.

    • Please see my website http://www.fightwildfires.com
      I will soon have spray hose systems to sell. I will sell you one at a steep discount to get some publicity.

    • Pamela Dunlap says:

      I’m also from Paradise- I’m pretty sure our rainbirds helped save our home but I feel you James, its really irritating to hear anyone say “your home can survive a wildfire”. There is no such guarantee, particularly once nearby structure fires are part of the equation.

      Ours was a very half-assed system- 2 rainbirds, one on each side of our 1970s California rambler. We happened to be home- actually spotting a neighbors house on fire before we knew the town was fucked, like others, not receiving timely notification to GTFO.

      We had an evac list, my husband banged on the neighbors doors- some of them still asleep- and turned on the rainbirds while I got the pets in the car. We were out in a flash.

      I don’t kid myself that it was exclusively the sprinklers.

      I know many with sprinklers lost their homes. THERE WAS A LOT OF LUCK INVOLVED. A fire like Paradise will allow NO GUARANTEED SURVIVING HOMES- post fire, we’d see all concrete homes, shells still standing- burned out from inside. You have a single window, you have a weak point for a fire like the one we lived through.

      Hell on earth. All you can do is slightly improve your odds. I think everything we did- the materials, the landscaping, and the rainbirds- may have improved our chance of surviving home like 20%. Still not great odds when only 1,400 homes survive and 19,000 burn- most people who did what we did still got screwed.

      I think the rainbirds, along with fire-resistant materials and landscaping simply improved our odds just a little, and luck took care of the rest.

      Only 2 homes on our cul-de-sac survived, all my direct neighbors homes burned. Our windows cracked from the heat of a neighbors burning home, but did not blow out enough to let embers in or provide a backdraft of oxygen.

      We had scorch marks on every single external wall, but stucco doesn’t want to take. Thankfully our former shake roof had been replaced with fire-resistant fiberglass/asphalt. All the tar melted out it was so damn hot, we had to replace the roof and deal with water damage since we couldn’t get in for so long after the fire. Our roof had ember pitting and damage where fire tried to take- but the rainbirds kept any from really taking off. Our gutters, despite our best efforts did have pine needles in them- it was Paradise in November, 2 seconds after you cleaned them there were more. They didn’t take, because they were soaked.

      Almost everything inside was smoke damaged despite the windows staying in tact, and we had to throw away more than half of what we owned, but at least we could salvage some memories.

      It took more than a year and over 100k to fix the damage to our home with a sprinkler, that “survived” and actually on a casual glance, didn’t look too bad when we first got a look at it. It was our second full time job- restoring the house, fighting with insurance that doesn’t think they owe you a damn thing because it “survived”- trying to find anyone who would work on it- mostly they didn’t want to, and we worked with a lot of handymen & felons instead of professional contractors, because the contractors were happy to focus on new builds.

      People frequently ask if it would have been better had it just burned, honestly I can’t answer that question. We got irreplaceable things back, but restoration may have sucked years out of my life.

      There is no easy way to survive what we did… but I am installing rainbirds on the roof of my new home.

      Despite expecting to move back, we sold the one we restored a couple weeks ago. Too much trauma, when I looked at its beautiful newness, all I had was bad memories of what it took to get there. Que Sera, Sera (Whatever Will Be, Will Be)

      • Thank you Pamela for sharing this. Your experience will help others. And you are right, there are certainly no guarantees… only things you can do to reduce the risk.

      • john dougherty says:

        Pamela, I am glad your house survived and even though you are struggling with insurance and smoke damage, I hope it is worth it, considering. I do believe that rooftop sprinklers are useful when part of a “holistic” approach. In other words: it can’t hurt. Good luck!

  3. I am in the process of developing a 100% self contained wildfire protection unit that will provide 150 to 250+ foot circle of defensible area. Options will include automatic starting, remote control, 3/4 hr to multiple hours of run time, fire retardant, maintenance programs and more. Prices will include setup and training.

    Interested parties please contact me with your specific needs and I will try to add them into the design.

  4. judie stein says:

    I want to find out how I can get this installed now. Does anyone have that information?

  5. Seth Price says:

    I’ve been searching the internet for some sort of automatic fire detection system that will trigger the electric start on a gas water pump. I haven’t been able to find anything appropriate for an off-grid cabin. I’m sure I’m missing something. Is there a list of fire detectors somewhere? Am I just googling the wrong terms?

  6. Jay Derwin says:

    why is this information sent to all town officials and homeowners

    • You mean why “isn’t” this info sent? That is the question we have been asking for years. Wildland fire agencies like Cal Fire and the US Forest Service are more concerned about clearing habitat and fighting wildfires than protecting communities, so that’s part of the problem. Municipal fire agencies are more enlightened, but many of them still just focus on vegetation too. We are seeing some changes, but not fast enough. It doesn’t help when Governor Newsom rejects bills that would help communities with retrofits.

      • john dougherty says:

        There is a lot I would like to say about “Municipal” fire agencies and city council’s reluctance to thinning green belts and shepherding the homeless out of these tender boxes, but suffice it to say that it seems like we have learned little from the Paradise disaster. By that I mean, it’s great to thin forest, but there has been no attention to evacuation routes in terms of adjacent vegetation. This is where the rubber meets the road: when people have to drive through burning trees to get to the hwy. We’ve seen how this works out.

  7. John, yes, the evacuation issue… they keep planning them based on the best case scenario. Consequently, people die.

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