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Built to Burn (99percentinvisible.org)
157 points by prostoalex 10 months ago | hide | past | web | favorite | 68 comments

Sounds like they could learn lots from Australia. Controlled burns are a norm every summer, CFA has pretty much everything from the article in their advice (https://www.cfa.vic.gov.au/plan-prepare/how-to-prepare-your-...), there are requirements for water tanks on new properties in many places. CFA mostly acknowledges the bush fire and lets it burn.

They did the same mistake with fuel buildup years ago, but it seems the transition to new system was much quicker.

Along with the majority of houses in suburban and rural areas having metal (Colourbond) roofs and brick walls means that the issue of embers discussed in the article would not be as dangerous to homes.

Brick walls are unfortunately not a good choice in earthquake-prone California.

What you are forgetting here is that people and the market build houses with a short lifespan in mind. They could as easily build new houses with reinforced concrete. And if there was that much earthquake consideration you would see support structures and dampeners as part of the regulation in non-trivial buildings (https://resources.realestate.co.jp/buy/earthquake-building-c...) (Also see regulation in Greece and Italy -- https://earthquaketrack.com/p/greece/recent).

The real estate market forces cheap wooden houses. It is not tradition or earthquakes... I feel here in California there is dangerous complacency regarding earthquakes (https://www.economist.com/united-states/2018/02/03/america-i...). People fear them but the rarity has transformed the fear into wishful thinking and avoidance.

Living in a country where pretty much _everything_ has been built out of brick/stone/concrete for a long while now (with clay shingles), I find US building codes to be baffling.

Not criticizing, mind you, since clay shingles are still supported by wooden beams in older detached homes and those go out too in forest fires (which we also have, on a yearly basis and with tragic results) - I just don’t get the rationale for small homes to be built out of wood these days - is it cost?

(Edit for typos)

The West Coast of the US is prone to earthquakes, and wooden structures survive earthquakes much better than brick structures do.

(They're also quite a bit cheaper.)

Wood framed buildings are much, much safer in earthquakes and with plywood shear walls can be considered the very safest construction method.

Aesthetically, I dislike it because I have a taste for very solid, permanent things, but if you live in California, stud-wall ("stick built") construction with plywood shear walls over them is really the only choice.

A wood house can be permanent if you get the moisture management system correct.

Americans don't believe me when I tell them my relatively recent regular UK house is built out of brick!

They say things like 'it's a wooden frame with a brick facade, right?' or 'I'm sure the supporting structure isn't brick.' No it's brick. It's all brick. The walls on all sides in every room are about 30cm of solid brick with plaster directly on top. Even the internal ones.

If you want to run a new light cable or something you'll be using a hammer and chisel to make a channel to put it in.

I don't think you could do this in California due to earthquake-related parts of the building code.

In the Christchurch earthquake in NZ, bricks were deadly. And Christchurch "didn't" have a faultline.

Also houses made from brick have a lot more damage in an earthquake - the mortar cracks and the structural integrity is lost.

That said, it was mostly older brick premises, chimneys, and facades that caused deaths. "Falling masonry killed 40 people in Christchurch's February 2011 earthquake"

Yeah, a brick house becomes a sandcastle in an earthquake.

We had the technology to build earthquake-proof houses for quite a while without needing to use timber framing which has all kinds of downsides.


The only advantage is cost and speed of execution, they call them McMansions for a reason.

Timber also has its upsides, including locking up carbon, and being easy to modify after the initial build.

Locking up carbon? The trees are produced / harvested according to demand, no? I think I may be misunderstanding your point in noting this.

Trees are made of carbon. Growing a tree takes carbon from the atmosphere and turns it into wood. When you build a house out of the wood that carbon stays in the wood for the newer few hundred years rather than going into the atmosphere, so staying ‘locked up’.

Dry, moisture-free wood is about 50% carbon by weight.

So if the panelised timber frame superstructure for an rectangular two storey house of 150m2 is approximately 14 metric tonnes, you're locking up 7 tonnes of carbon for the life of the building (minus of course the carbon emitted to plant, prune, fell, transport, mill, treat, get the wood to site, install it etc.).

If you can use more timber through the construction, all the more effect.

Doesn't the same amount of carbon stays locked the same in a tree in the ground? I don't understand why building with wood helps in this case. There's plenty of space to grow more trees...

There's not an infinite amount of space to grow trees actually. A decent forest needs the right climate, water. Economically forestry must compete with other land uses such as grazing, orchardry, etc.

It takes pinus radiata about 25 years to reach maturity. Then it can be turned into buildings/ houses, and the carbon locked up in that structure, which can be e.g in the city or suburbs- somewhere there will never be suitable for forestry.

And then the forest can be replanted and the virtuous cycle begins again.

tldr; locking carbon up in timber gives more flexibility than just relying on standing forests.

If you’re buying the wood then someone is being paid and incentivised to plant more trees to sell next time.

Outside the warmer areas of the US, I think a big reason for wood framing is how easy it is to insulate.

I'm not sure how it's done in the UK with brick buildings though. It seems like if you needed much insulation you'd end up with an inner wall and brick facade.

Two layers of brick separated by an air cavity in the old days (c. 1970) and more recently with foam, glass fibre, or rock wool.

UK: Breeze block inner, cavity with rock wool and brick outer with internal walls of basically studding with plaster board for my 1985ish 'compact and bijou town house'.

Some medium-rise blocks of flats use steel frame floor plates from concrete central pillars with external cladding approach but most new houses are brick.

Partially and historically the US has had a lot of wood, the UK deforested early (we built a lot of ships and wooden structures) so we had to go to brick and slate quite early (also our climate is hell on wood without modern treatment).

Also the US climate is far more varied than the UK's so in some biomes wood makes sense.

A lot of the interior West and SoCal where fires are the most intense is unforested. A good deal of the lumber used to build is shipped in from elsewhere.

My home state of Idaho (the south) is largely cheatgrass, tumbleweeds, and sagebrush. None of which are useful for construction. All extremely flammable most of the year.

Not sure where you're from, but cheap lumber, bro. California has lots of forests, and therefore timber framing is comparatively cheaper here.

Most (all?) California residential including apartments are wood framed for earthquake survivability of the residents. https://www.nytimes.com/1999/01/31/weekinreview/the-world-on...

Reinforced concrete frames are also earthquake resistant and fireproof, e.g. popular in Greece. Search "Eurocode 8" for reference.

The sheer stupidity of having a wood shingle roof in a place with the Santa Ana winds astounds me. That’s wasn’t against code?

This was such a fascinating article. Classic government intervention, focusing on large projects that are ineffective and not backed by current science instead of direct interaction with the problem door to door in lots of smaller expenditures that would actually be effective.

Wood shingled roofs are currently against code. The wood shingle example was from 1980. Current code even disallows wood decks.

My childhood home burned in the Oakland hills fire - and it had a tile roof -- so roofing material is not enough. Having a defensible space also seems key.

On a related note - I watched a youtube video on a woman driving up and down the streets of Paradise to show people if their homes survived. The homes that survived all seem to be surrounded by a watered lawn. This reinforces maintaining a defensible space is key to survival.

In this particular disaster, there are more factors than defensible space. Some well-maintained, well-built homes with large yard spaces are ash now; other homes with no defensible space at all came out unharmed, including one with several cars in the yard and a 5 gallon can labeled "flammable" right against the garage.

Removing fuel from on and around your home is a good idea regardless. Beyond that, I don't think most of us are qualified to guess on the fire behavior in Paradise (or Redding, or Napa, or Santa Rosa...).

I will say that of the buildings still standing in Paradise, a disproportionate number of them seem to be brand new construction (<5 years old).

I don't know if you've ever been to or through Paradise, but its very similar to many foothill communities in the north and south Sierras, in the sense that the town was effectively built into the surrounding forests. The forest in that area is primarily Ponderosa, and pretty decent sized ones as well. In this sense, and I can speak from authority as I've spent far more time in Paradise than I would have preferred (reasons below), pretty much the entire town had negative defensible space. Most of the houses in Paradise are (were) fully surrounded by 50-120 foot pondos and under a closed canopy.

Likewise, most of the new construction was built on the ridge (Skyway) between Paradise and Chico, which is primarily California live oak and grassland.

A huge mitigating factor in all of this however, is the level of poverty in and around the (former?) town of Paradise.

Not sure how well this has been represented in the media, but Paradise as a community is poor as shit. There are just about -shit_all- jobs (outside the hospital) in that area that don't involve selling cigarettes and lotto tickets. Paradise, Concow, Magalia, pretty much some of the poorest areas of California I know of. Many of the families in that area lived on properties that had been built over several generations, handed down from gold-rush era mining claims. These aren't people who keep insurance on anything. Nor are they the kind of people who concern themselves with maintaining a defensible space around their homes.

I stayed in Paradise for a handful of days around a month ago. Nice people and town, and I'm really saddened to see what's happened to them.

As the article points out, there are some interesting areas where there are green or just lightly singed trees surrounding homes that are totally gone. Certainly there are also a lot of trees that clearly went up like torches. There was also a place where the fire came halfway up the front yard and then just ... stopped. If I remember right, that yard was mostly bare dirt though with just a light layer of pine needles, which don't burn well. Every place around it was completely gone, and I mean completely. They had a neighbor's house all of about twenty feet from their house. Neighbor's house is just dust, the wall on this house wasn't even darkened.

The new construction I was talking about were individual buildings or, in one case, a small series of retail spaces. Everything surrounding them was just ash.

So there may be some merit to what the article's saying. It kind of explains some of the oddities I've seen. I didn't get to survey the area in detail before it was destroyed though.

I've been out there one full day so far on the ground in a SAR team, and I'm scheduled to be out there again Sunday through Wednesday in overhead. I wish I could be out there more but my day job is being a bit difficult right now.

I am on another list with fire fighters all expressing their opinions. Here is what one said:

I just got back from Butte Co - the ignition point in Pulga wasn’t deep forest, but grasses, shrubs and forest patches littered with downed and dead woody debris. Seems like a big fuel break by Pentz Road could have helped. It wouldn’t have saved Magalia and Concow but would have given Paradise residents more time to evacuate.

But at the same time, watering a lawn is incredibly wasteful of water, in a state that’s in a more or less perpetual drought at this point.

Long term you need regular controlled fires, and no one planting explosive trees (eucalyptus being a good Bay Area example of terrible ideas)

I'm amazed at how many places appear to be opposed to steel roofing. Everywhere I look, it's asphalt shingles in new construction. I'm in the northeast, so the main problem here is snow load - which is a PITA with shingles, and you've gotta shovel your roof off - not fire, but still, if you've got swirling embers that land on a steel roof, the worst they'll do is scorch the paint.

Steel roofs are three times the price.

I don't think that's accurate. Maybe for standing seam, but the screw-down panels aren't that pricy, and it takes less work than nailing shingles.

Are they noise dampened? What is their sound profile during precip?

Also, if your house is on fire and firefighters need in thru the roof, steel makes it harder for them to get in.

Any home I have been in you can definitely hear the rain falling. But it is one of those noises I think you can find relaxing like a fire crackling. The thing I disliked about the metal roof was the major decrease in cell phone signal.

I have a perfect solution for all those issues. Bonus: it's been done for centuries in Europe, tried and tested, it's called "clay shingles". You can observe them... everywhere you go in Europe.


Bonus: clay shingles are the longest lasting material you can cover a roof with, and you can repair it by sections. It also looks way better than the crap we use to cover roofs in the USA.

Not perfect: one anecdote from maire above to disprove: "My childhood home burned in the Oakland hills fire - and it had a tile roof -- so roofing material is not enough. Having a defensible space also seems key."

But did that home burn from embers landing on the tiled roof, or from being consumed by the actual fire?

My guesses: Either more expensive or not earthquake-resistant.

Rain in California?

That's the market telling you not to build in a fire-prone area. Paying a gardening crew to thin the vegatation around your house to provide defensible space is also the market at work.

Do they have to be replaced as often?

What makes you so sure the perspective in the article is the more scientifically accurate one? It was written without almost ANY opposing research being quoted. I found it very hard to come away from this article wholly convinced it had found the best perspective on the issue.

It’s also the case that the article focused mostly on preventing home fires caused by forest fires but then the article itself shows this is a very rare phenomenon. Not exactly something that should be a core focus in the first place.

The lessons of the Great Fire of London still apply. Yet discussion moved on to this idea that 'natural fires' should not be suppressed as this causes too much dead wood to build up on the forest floor meaning that the 'natural fire' burns too intensely.

That massive fire in Yellowstone way back in 1988 was when this new thinking set in. From then on the Forest Service could be blamed for poor management and allowing this kindling to build up, resulting in truly catastrophic fires. It was a seductive way of thinking and whilst everyone was thinking it the basic lessons of The Great Fire of London were ignored.

In The Great Fire of London the problem was the wind and embers being blown across town to start new fires. This overwhelmed the authorities of the time. The solution was to build houses with non-flammable materials. In that way an ember landing on a house would not cause another fire to start up.

The other detail of note was the use of parapets. In London roofs are always behind a parapet, so, if a house or property does go up in flames then the roof will not fall off the house but be contained within the four walls. In this way adjacent properties, e.g. across the street, don't go up in flames too.

Nowadays building codes in London expect a property to not go up in flames even if the adjacent house is fully ablaze. This is buying time, clearly there is expectation that the adjoining fire gets put under control within a few hours. It doesn't seem that in California there is this thinking, which is understandable if you do have lots of garden and some distance to the adjacent house. But I bet that the first people to populate London thought that way too, they never imagined the pasture land next to their house would become a housing estate some centuries later.

Another small matter is that of sprinkler systems. Architects do not like sprinklers even though they do a fantastic job of suppressing fire. They also design atriums with no vents in the roof specifically there to let hot air out if there is a fire. This is considered old fashioned thinking by the entire architecture business, they check the checkboxes on building codes at minimal cost and don't think from first principles about how to make a building work within its environment.

City fires are completely different from forest fires. For example, the parapets you're so focused on don't make much sense when houses are 100s of feet apart, as is the case in a lot of places that are burning.

Also, London is a different place than California. Buildings in California aren't built with wood for no reason; they do it to withstand earthquakes. There's a big difference between just fireproofing a building and simultaneously fire- and earthquake-proofing a building - the latter is far more difficult and expensive.

I don't see that many of the lessons from the Great Fire of London apply to the problem in California.

I did write that the parapets of London were just a detail, not the focus. I also mentioned that conurbations attract more people over time and land that was once sparsely populated soon gets crowded. In America this might seem unimaginable but if the internal combustion engine dies then so does American suburbia. Those 100ft exclusion zones are not going to last forever however you look at it. It could therefore be prudent to build your house so that if it goes up in flames it is not going to turn the whole town to ash, even if the whole town is not there yet.

My general point regarding the Great Fire of London being that fire prevention has been worked out a long time ago. Fire prevention with earthquakes is actually well worked out too. Despite American exceptionalism California is not special. Half of mankind lives in an earthquake zone. The reason for this is that the most fertile land happens to be in earthquake zones, you need some volcanic goodliness to make it so.

I accept the point made by the lumber lobby that wood is a great material for building houses. Wood can be marketed as fantastically earthquake proof if your quarterly sales matter more than the dreaded Spotted Owl. But is wood really what you want for a house that is an actual home? To last for generations? What if you live in Italy where earthquakes happen but there is no lumber lobby just up the road?

Time is money and convenience is king. It's the American Dream. There is no need to be encumbered by things like sensible building codes if there is no past and no imaginably sustainable future, just the urgent, dramatic now.

The culture of consumerism plays its part too. If you are a property speculator in a drought-stricken earthquake zone where fires ravage the countryside every single summer (unless it happens to be an el-Nino year when flooding takes over) then it could be hard to find a market for homes built to last for generations.

Why do that when you can flog a slapped together McMansion with double garage side portions for much more profit? It only has to last until the next boom/bust inflection, savings + loan scam or catastrophic 'act of god'. Hollywood's back lot sets are more substantial.

I very much like Californian vernacular architecture however I am far more likely to be taking pictures of the scenery rather than of any house when in California. The truly beautiful houses with character are outnumbered by seen-it-before identikit dwellings or those McMansions that have no taste whatsoever. I have actually got lost in several Californian built up areas due to the lack of unique landmarks. I haven't had that problem anywhere else, even Soviet era centrally planned housing can be navigated without feeling like you are stuck in some maze.

In summary, fires don't care if they are in California or anywhere else. The short-term-ist consumerist outlook that goes with the territory is the problem, not some unique combo of fires and earthquakes.

> Fire has no boundaries and no preference for where it burns

That's a weird thing to say: there are definitely places that are more fire prone than others.

Been a couple days but, IIRC, that statement followed an explanation of why embers and certain kinds of roof design don't go together. (don't think it was intended to be generic)

The second part of this (podcast, see Episodes 317 & 318 in http://feeds.99percentinvisible.org/99percentinvisible) goes into changes in Montecito, CA. IIRC, their last exposure to wildfire resulted in very few house losses.

The Paradise Fire might have been an entirely different beast than the survivable events that are primarily discussed in this article. (I still think this is a great article; bookmarking for reference.)

But the Paradise fire moved so fast, and so tall, I don’t think anything stood a chance. Look at, for instance, the Safeway in the town — completely demolished.

Flew over the area the other day — got a first hand look at the smoke from above which we’ve all been breathing in down in the South Bay all week; tragic, devastating event.

Edit: primarily talking about the stuff related to landscape and building design. I’m in favor of controlled burns, but it’s not trivial to start doing it given just how much fuel is built up in California.

>I don’t think anything stood a chance. Look at, for instance, the Safeway in the town

Eh, I would disagree. Pull up google maps and drop in street view. This town, in the middle of fire country, is filled with pine trees. Many of them have ladder fuels under them. Tall fires happen because of crown fires.

Speaking with a guy from a forestry service who studied fire impact mitigation strategies, apparently the cheapest, effective approach is for each home to have an emergency water sprinkling system that covers the entire house and as much of the property as the owner wants to preserve.

Sure there's a cost to this but is it really so much different that having sprinklers in high rise residential buildings?

It seems a sprinkler system on the roof, in addition to the yard, would go a long way in terms of embers. Just keep everything saturated?

As far as I know California is already short on water. Would a sprinkler in every house system be sustainable or even possible in such conditions that everything burns?

You would have to have a pressurized water storage tank at each house. It would be quite expensive and have a lot of maintenance for how rare the usage would actually be.

CA has frequent water shortages, and is in drought conditions right now. Where would the water for the sprinklers come from? What is going to raise it from the underground water source to the roof level? Electricity, which may not be available? Are you going to retrofit a large and heavy cistern on every roof, that relies on gravity to distribute the water?

It can be done on a community level, not individual houses. In Portland, we have several HUGE water towers that hold tens of millions of gallons that supply pressurized water to neighborhoods, like the Denver Water Tower. They also have them on the ground in hills where you can't see them, supplying houses below. For fire suppression, it doesn't have to be potable water. It's just a quick thought I had. I know if I lived there and there was a fire breakout and heading towards me, I'd stick a sprinkler up there whether there was a water shortage or not.

The whole way houses and cities are built in California is to blame for this tragedy (not discounting the effects of global warming of course).

It's high time California realizes building wood framed boxes with walls of compressed paper with no defensible space between the wilderness and the houses is a BAD idea and we start building with more sensible materials like concrete, bricks and stone like Europe has been doing for centuries - because it works.

Eh, telling people to build with brick in earthquake zones is a bad idea.

Of course putting pine trees beside houses in fire zones is a bad idea too.

Ever heard of concrete?

Also, there's plenty of earthquake resistant techniques you can apply to masonry. Mediterranean houses are all built with steel-reinforced concrete and bricks even now and there's all kinds of seismic activity over there.


Hmm, I thought controlled burns were best practice and was being done. Is that not the case?

Controlled burns are best practice but are not being done. For federal land, agencies have had their budgets repeatedly cut. This has left less money for thinning and other prevention work. Fire fighting money comes from a different "emergency" budget even though fires happen every year so it's not really an emergency. For private land creating a defensible space is on the books but is not being enforced.

"For private land creating a defensible space is on the books but is not being enforced."

That depends on the area...

I am a volunteer firefighter in Marin County (basically San Francisco) and we do defensible space consultations all summer and the paid firefighters of Marin County do indeed drive around all summer writing fix-it sheets for homeowners that are in the wildland-urban interface.

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