Disturbing Fire video -- sad for the house-proud

[DoomsDave]

Howdyall:

The vid in the link was shot during that nasty fire in late 2008, after our PSSC meeting, sad.

Burning palms, and burning houses, firemen doing their best.

Lessons?

Oh, let's discuss. If you want.

I'm thinking: where's my fire hose? But . . .

Of course, if I'm breaking a rule I implore the mods to delete this post.

[DoomsDave]

And, another.

[Kris]

Dear Dave

Thanks for the video links...i could imagine how dangerous these fires could be.

Kris.

[DoomsDave]

worse than anyone could imagine . . .

[pq_bob]

worse than anyone could imagine . . .

You got that right Dave, I have talked with fire victims that said the experience of their house burning down was so horrible that they would almost rather die than go through the whole experience of the house burning down, running for their lives, then fighting with the insurance company.

Sorry this is so long, but I spent almost every night for a year researching what things can be done in advance of a firestorm to try to make sure my house is still standing because I panicked that day in October of 2007 when about 45 minutes after very strong Santa Ana winds started blowing, there was smoke blowing straight toward my house. I turned on the TV... nothing. Radio...no news. I thought great, I don't even know where the fire is at, how big it is... I thought, my house is going to burn down, and there is not a thing I can do about it-- as I looked at the wood chip mulch beds that were touching the house, the leaves in the gutter, etc.

The good news is that I was wrong, although there are no 100% guarantees of a house surviving, there are a lot of things that can be done by the homeowner about this problem. You just have to break the problem into 2 parts.

1: Ignition because of flames, and

2: ignition because of embers.

1. Flames: Fire research scientist Jack Cohen has been studying this problem for years. One summer he built wooden structures 33 feet, 66 feet, and 99 feet from the edge of several large multi acre patches of pine forest. Then he set the forest on fire. There was a 60+ foot wall of flames that approached the structures. The fire generated it's own powerful wind as it whipped the clothing on test dummies nearby. The structures at 66 feet and 99 feet away did not ignite at all. The structure at 33 feet ignited for a few seconds, but went out by itself as soon as the flames from the forest died down. There are movies of this experiment on the internet. 100 feet of defensible space is important because it is for solving the ignition by flames part of the equation because you are keeping the wall of flames at least 100 feet away. People that live in typical developments with the houses about 15 feet apart are in real trouble of their house catching on fire due to their neighbors house catching on fire during these firestorms. So ideally, fire prevention would be a community level effort with each neighbor creating defensible space and doing fire prevention measures on their house.

2: Embers: Australian research has shown that live embers can typically fall as far as 2 miles ahead of a fire front. Scientists from the Fire Research Laboratory at the National Institute of Standards and Technology (NIST) have documented evidence that embers from the Wïtch Creek fire in San Diego, California of October 2007 traveled up to 5 miles ahead of the fire front. This was due to the hurricane force winds occuring at the time. The research from firestorms over the years also shows that roughly 80% (it varies from fire to fire) of the houses destroyed were due to an ember catching something on fire on, insude, or next to the house. So in reality, the embers are by far the biggest problem. The first report from a series of reports on the Witch Creek fire was published by NIST in 2009 and can be seen on the internet.

A few ember mitigation measures...

- There are specially designed vents that prevent ember intrusion into the attic space, which is a very common occurance.

- Leaves can be cleaned out of the gutters to prevent an ember from igniting them, which then ignites the wooden framing underneath the roof covering.

- Leaves and dried grasses can be cleaned out from underneath decks, as well as blocked with a 1/8 inch metal screen to prevent future accumulation of leaves.

- The gap under the garage door can be closed off with weather stripping to prevent embers from blowing into the garage.

- Wood shake roofs are the worst and have been described as putting kindling on top of the house. During a mild Santa Ana wind event in October 2008 there was a trash can fire in my neighborhood which spread to some Italian Cypress trees. The house nearest this mess just got a little scorched. However, the embers traveled a block away to the only house on the block with a wood shake roof, ignited it, and the house was completely destroyed. The house is finaly now under construction. NIST found that every single house with a wood shake roof within the fire perimeter in the particular neighborhood they studied was completely destroyed by the Witch Creek fire.

I love my palm trees and won't part with them, but unfortunately a lot of my species have "hairy" trunks that catch fire easily and dead leaf bases that can accumulate embers and catch fire. NIST documented dead Washingtonia fronds that caught fire in the Witch Creek fire and then blew over 100 yards away from the tree. Once the leaf base burns off, gravity and the wind take over. I talked to a retired firefighter and he also said these types of palm trees easily catch fire during a wildfire from the embers. There is a long lasting fire retardant product that I spray on the trunks of my palms. I tested it by throwing a hunk of treated palm tree hair into a barbecue.

These are just a small fraction of the things that can be done around the house, and they help the firefighters while they do their job. Of course, the more fire prevention measures that are taken, the higher the odds that your house will survive, but even if you can do some things it is better than nothing. From their Witch Creek fire research, NIST found that the homeowners of the most prepared houses that survived within the fire perimeter had done only about 2/3 of the items on NIST's fire prevention check list.

San Diego is in the cul de sac of California. There is a desert to the east. Firefighting help is going to take a long time to come from that direction. There is not going to get any significant help from Mexico. There is not going to be any help from the ocean to the west. That leaves the north as the only viable direction of reasonably quick aid. Typically the wind storms in fire season blow from east or northeast to west here, but the whole storm moves from north to south so mutual aid resources are already commited to fighting fires already started to the north of us in the hours before the wind begins to blow in San Diego. During the 2007 firestorm, the San Diego fire department requested mutual aid and was told "sorry, we are out of resources, you are on your own". This was for the first 24 to 48 hours after the fire started. The point of this is that the firefighting resources are going to be very thin and firefighters have to quickly survey a neighborhood and pick and choose which houses they think they can save through a process called structure triage. They simply don't have time to put out already burning houses or time to try to save house that will take a lot of their time. So if the fire fighters can see your defensible space and other fire prevention measures, they are going to be much more likely to pick your house to save. So there are two benefits to fire prevention-- you increase the odds of your house surviving on its own and increase the odds that firefighters will attempt to save it.

Budget cuts are another thing. The fire station near my house is the busiest in the city since it covers a large area. It used to have a fire truck company and a fire engine company, but now is down to just the one truck company due to budget cuts. With all the budget cuts occuring in fire departments here, the resources are going to be even fewer and far between in the next fire disaster. It is more important than ever for homeowners to take responsibility to perform fire prevention measures around the house.

I see that the video posted here has over 8600 views, whereas the video titled Wildfire! Preventing Home Ignitions only has about 20% of that number. It is way more boring to watch a fire prevention video, but it is a good way to learn.

[MattyB]

Good stuff Bob. Thanks.

[DoomsDave]

Bob:

EXACTLY the kind of post I was hoping for!

I'm going to save this in my archives . . . .

Thanks again!

[pq_bob]

Glad to be helpful. Here are more things that might help.

How to discern plants that are highly flammable:

Look for plants with:

- an accumulation of dead leaves or dead sticks on or around the plant (acacia)

- shaggy, hairy, papery, peeling bark (Eucalyptus, Melaleuca)

- dead, dry interiors (juniper, Italian Cypress), embers get blown into the interior by the wind

- fragrant aroma when you crush the leaves in your fingers. Often the plants with the highest oil content will be aromatic, for example rosemary. Plants with high oil content tend to be flammable and burn with high intensity.

I always thought ice plant was fire proof. It turns out that no plant is absolutely 100% fire proof. A firefighter told me that over the years an inch or two thick thatch of dead material builds up underneath the ice plant. When a wildfire comes, this material can and will ignite and burn underneath the green part up to something flammable like a deck or a fence. Look at the ice plant around your neighborhood and you might be able to see an example of this dead thatch where someone has trimmed the edge away from a sidewalk.

There is a plant flammability guide from the Ventura County Fire Department, www.countyofventura.org Click on Prevention, then click on Wildfire Preparedness, then click on the Plant Reference Guide toward the bottom. No such guide would ever be perfect, and regular plant maintenance as well as spacing between plants and from the house make a big difference, but it gives you some ideas.

If you live in California, you can find out if your location is at risk for wildfire. I had it all worked out in my mind that my neighborhood should be safe, but in reality it is not according to the map. The easiest way to get to this is to type "local responsibility area" including the quotes into Google (I know it's bizarre, but it works). Then click on one of the first items which will say something like Cal Fire - Wildfire Hazard Severity Zone Maps. Then click on view and download. Then click on your county near the bottom of the page. Then download a map under the "local responsibility area" heading. None of the maps are easy to read, but the ones under this heading are the easiest to read because they are the only ones with streets. The bad thing is that the streets are not named. Once you zoom into your area, it is not too bad to find your street.

firecenter.berkeley.edu has some material. You can do a wildfire hazard assessment on your home and the Homeowners Guide to Wildfire Mitigation is excellent because it shows pictures of different fire hazards and pictures from various fires showing the origination points of ignitions on various structures like decks. They say a picture is worth a thousand words.

www.firewise.org is another good resource.

The Escondido fire department has a good powerpoint presentation with lots of pictures that will give you some good ideas. www.ci.escondido.ca.us/fire Click on wildfire resources, then click on the Wildfire Mitigation Slideshow.