Preparing For Wildfires With Fire-Safe Home Construction And Retrofits
May 29, 2013 1:09 p.m.
Rick Halsey, is director of the Chaparral Institute. He specializes in wildfire ecology, and is also a former wildland firefighter.
Jack Cohen, Research Physical Scientist for the Missoula Fire Sciences Laboratory...He specializes in home ignitability research
CAVANAUGH: Recently we had a panel decision on Midday Edition focused on a statement made by governor Jerry Brown about California wildfires. The governor said our climate is changing and we need to prepare for longer fire seasons and more dangerous fires. During that first discussion, our panel raised the issue of where and how homes are built in Southern California. Home construction is emerging as a major factor in the effort to mitigate wildfire damage. Today we'll focus exclusively on preparing San Diego County's homes to become more resistant to wildfire destruction. Rick Halsey is director of the California Chaparral Institute, he pleases in wildfire ecology and is a former Wildland firefighter.
HALSEY: Good to be here.
CAVANAUGH: Jack Cohen is a research follow scientist for the Missoula Fire Sciences Laboratory. He specializes in home ignitability research. Welcome to the program.
COHEN: Thank you very much for having me.
MAUREEN CAVANAUGH: Having a home in the path of a wildfire doesn't necessarily mean that your home will burn. What have you learned about the characteristics that make a home ignitable?
COHEN: Well, I'll go ahead and start on that. The research that I've done indicates that the principal determinant of home ignition and destruction is actually the home characteristics in relation to its immediate surroundings within about 100 feet. And of course that varies depending on the overall conditions. But what that says is that even during intense, extreme wildfire conditions, the flames can be kept about 100 feet away. Obviously the burning embers that are lofted out of the extreme flaming are going to land on and around the house. And those ignition conditions can be mitigated at the home in relation to its immediate surroundings. So even with extreme wildfire conditions, the house can be modified, the conditions of the house that makes it ignitable can be modified such that it is far less vulnerable to ignition.
CAVANAUGH: You've written that the usual result is that a home either survives or is totally destroyed. Partial damage is rare. Why is that?
COHEN: Well, one of the predominant characteristics logistically during one of these events is that there is a very extreme exposure level, compared to the amount of firefighting resources that can cover that exposure. Flames and firebrands. So the number of homes that can be exposed to a potential ignition far overwhelms the resources that can even put out the small ignitions. So any sustained ignition on a house however that happens ends up burning to total destruction am
CAVANAUGH: You've also compared regular residential fires in relation to wildfires in the way that homes burn. How are they different?
COHEN: Lvery typically, during a wildfire, the ignition source is external to the structure. And so with the exception perhaps of burning embers going in through vents, but even through open doors and windows when people leave in a rush, the flame, the initial ignitions are typically on the exterior of the house. So for example, if in the extreme case of a flammable roof material, it readily ignites from deposited burning embers, and basically the house burns from the top down.
CAVANAUGH: Therefore would it be a good idea to close all your doors and windows if you're going to be evacuated because of a wildfire?
COHEN: It certainly would. I'm not suggesting that you necessarily lock everything up to be secure just because there will be responding firefighters. But definitely get your house as tight as you possibly can. Obviously with doors and windows. But also before the wildfire, during the year particularly when conditions are going to get dry and windy, look at those areas around your house where burning embers could ignite something. So for example, dead material next to your house in the rain gutters. And locations like that.
CAVANAUGH: Rick Halsey, we used to have a lot of flammable, shake shingle roofers in San Diego. You don't see many of them anymore. What kinds of fire safety home construction now could make a difference here in San Diego County?
HALSEY: Well, jack's research that he's done has been remarkable. Elucidating the main problem, and it's about the house and construction. Unfortunately most of the emphasis when you hear it on the news or from politicians it's about wildland fuels. So I'd lick to see that shifted in the direction of the actual science instead of where the money is. The money is primarily being poured into habitat clearance operations. So once you start looking from the house, you start from the house and move out.
CAVANAUGH: Right, the defensible space idea.
HALSEY: Right. So one of the key features in the 2007 fires, there's a couple excellent research papers that came out, virtually none of them ignited because of flames hitting them. They ignited because of embers and that kind of a thing. So a response to that should have been let's come up with a way to retrofit these vents, help these people fix these homes that are basically fuel and make them fire safe. That's the way to approach it. They spent $7 million right after the 2007 fires on some fuel treatments or habitat clearance operations in the Julian area. If they spent that $7 million in helping homeowners retrofit vents, that's what would save homes. Homes don't burn now because we understand the clearance and vegetation treatment program. They typically burn because of these embers. So if you can attack that -- in the witch creek fire, for example, you could easily estimate 50% of those could have been saved with a retrofit.
CAVANAUGH: What kinds need a retrofit?
HALSEY: The old fashioned ones that you see in old homes. You've got this huge wind of these killer embers coming at your house by the billions, and it creates sort of a suction situation with the turbine vents at the top. So it pulls all of the embers into the home, and you've got this incubator of flames. There were a lot of homes in the Scripps Ranch area that got ignited right away by 8:00 in the morning. Then the fire crews left, at 3:00, there was another burst of fire. The fire was out, but the embergot into the houses and ignited. If you continually focusing on a different issue, you're never going to be able to fire safe communities.
CAVANAUGH: You both talk a lot about litter around homes and things like mulch and birds' nests being fire hards. We are told to create defensible space, but that -- the concentration is really on clearing brush up to a certain amount of yardage around your home. Should homeowners do more closer to their home when is it comes to trying to think about what might be able to catch fire when it comes to burning embers?
COHEN: Well, when I do training for people who are going to access homes, and where it's during a fire situation or whether it's beforehand, one of the things that I emphasize is to start with a house. Rick said this. You start with a house then you work out. One of our disabling or impeding perceptions is that somehow or another we need to control the wildfire in order to keep the house from burning down, and that's not the case. What we need to be doing is looking for those small ignitions that can occur on the house and then around the house, and then lastly begin to take a look and see what kinds of intensity will be generated within 100 feet of the house and mitigate those. One of the things I've found in all of the examinations that I've done is that most of the houses are burning within a neighborhood well after the wildfire has ceased its extreme activity around the neighborhood. So what we're seeing here are relatively small ignitions, burning brands igniting the house directly, as well as igniting dead vegetation around the house that spreads as low intensities to make contact with the house. As I mentioned earlier, the ignitions tend to be exterior to the structure or in structural materials on the very inside of a structure, and that takes quite a while to become a fully involved structure.
CAVANAUGH: Now, you talk about firebrands, is that the same as embers?
COHEN: It is.
CAVANAUGH: Let's talk about where homes are built and how that increases the risk of houses burning during a wildfire. We've heard a lot about how development is pushing into high-risk backcountry fire areas. Rick, is that continuing here in San Diego?
HALSEY: People feel they have the right to build wherever they want. I'd like to turn it around and say do you have the right to put a firefighter at risk? That's happened several times. We've lost several firefighters in Riverside County several years ago because they were defending a home that shouldn't have been built in the first place. And the political leaders need to have the courage to say no, we're not going to put our men and women at risk. You quantity build there. Some of the homes that burned in 1970 during the Laguna fire were rebuilt, that got burned again in 2003. But on the other hand, it's okay. If you want to build there, fine. Accept the risk. Don't blame the fire service when your house burns down. Don't have the politicians come out and demand clearance of the entire habitat for miles around which is essentially when they continually advocate. Accept the risk, you're a private citizen, and if your house burns Tburns. And that's acceptance of responsibility in a way that I don't think has really been discussed too much.
CAVANAUGH: In looking toward the future, we have an awful lot of canyons in San Diego County. And I have heard them referred to during wildfires as sort of fire freeways. Is that something that you think land planning officials have to look at more closely when it comes to whether or not there should be home there is?
HALSEY: Sure. Every firefighter who's been out in the field enough knows these fire corridors. You can just sort of spot them. I talked to the former fire chief of San Diego City before I knew much about fire. The witch creek fire, I thought there was just no way I would have thought this would have happened. He shook his head, we knew this was going to happen years ago. Firefighters understand this. New developments now are beginning to be built properly. There's a community in Escondido, it's remarkably well built. Those homes are so well structured, are there's nothing flammable, and the vegetable is about 150 feet away. And the material in between has been thinned. It's not a moonscape. And so you can build communities in areas that aren't fire corridors that can be safe. But you've got to lead those areas, and that means planning, zoning, but if you want to save lives, that's what you have to do.
CAVANAUGH: So the idea is maybe taking another look at land planning for individual homeowners to look at their homes and see whether or not they could use new vents or retrofit their home for fire in one way or another. Could insurance cover these? Playing a bigger role in stimulating people's desire to retrofit? And make wildfire home modifications?
HALSEY: Sure. One of our dreams we've talked about a lot in these discussions is to have a good student discount for a fire-safe home. But my understanding of insurance, and I'm not an expert, basically insurance companies deal with a list of ten things. Doing bites, irate neighbors, the toilet leaks, those are the big expense items. Wildfire, even though it's such a dramatic thing for us, there's not much --
HALSEY: Incentive, thank you, for that kind of thinking from what I understand. So we turn to the insurance companies to ask for help on this, but it hasn't really been forthcoming. A lot of the insurance companies unfortunately have actually raised rates to the point people can't get insurance, then they use the fair plan in California.
CAVANAUGH: Let me end this with you, Jack. You make the point in your writing that local governments shouldn't think of homes only as potential victims of wildfire but potential participants in the continuation and spread of the fire itself. With that mindset, do you think government might be motivated to increase some sort of regulation or motivation for people to retrofit their homes?
COHEN: Well, instead of making a comment on what they should do, let me make a comment on the opportunity to significantly reduce the vulnerability of houses, both those that are planned in the future as well as what currently exists. What I want to emphasize here is the fact that we have an alternative to what we're already failing to be able to do and that's to stop the disaster. We do have the opportunity to keep houses or to reduce the home ignition potential and to increase the effectiveness at the same time of our firefighting resources.
CAVANAUGH: Okay then. We're going to have to leave it there. Thank you very much. A lot of really good information. Rick Halsey, director of the California chaparral institute, and jack Cohen, research physical scientist for the Missoula Fire Sciences Laboratory. Thank you both thank you very much.
HALSEY: Thank you.
COHEN: Thank you very much.