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I'm wondering if fire-prone areas should be zoned to require fireproof building. No more wood homes/roofs. Europe generally doesn't use wood home construction,

I'm wondering if fire-prone areas should be zoned to require fireproof building. No more wood homes/roofs. Europe generally doesn't use wood home construction, so doesn't seem crazy

gkop 5y ago
> if structures near fire-prone areas were designed and maintained to withstand fire, we might not need to fight some wildfires at all. https://99percentinvisible.org/episode/built-to-burn/ https://99percentinvisible.org/episode/built-to-burn/ I think you might be getting downvoted for "fireproof" which sounds absolute, and is probably not realistic. But you're right that regulations should evolve to require responsible home design and maintenance in fire-prone areas!
- Syonyk 5y ago
  ++ for an article that mentions Jack Cohen. If you want to understand wildfires, read everything he's written. He's basically the single handed Mythbusters of wildfire understanding, and has done things like "instrumented crown fires of test stands" to better understand radiant heat flux from actual fires.
dntrkv 5y ago
I’m not an expert in the matter, but I’ve heard that modern wood frames are just as good as steel frames. If the fire is close and strong enough to ignite a wood stud, the steel stud would already fail. Though would love input from an expert here.
- josephcsible 5y ago
  Wouldn't the steel stud just structurally fail, rather than also becoming more fuel for the fire to spread to?
- Syonyk 5y ago
  Not an expert, but have done a lot of reading and some writing on wildfires, fire resistant structures, etc. I live on a hill that catches fire rather more often than I really enjoy and spend a lot of my spring cutting firebreaks. Any sort of structure, wood or not, will withstand a huge radiant flux of energy before catching fire. Well, well beyond what will crispy fry a human, the siding may be charred, but it won't burn. Even wood siding tolerates a lot. What lights houses on fire are firebrands - "burning crap from the sky." Trees, mostly, embers, other houses... that's what catches things. Typically it will light some small stuff near the house first, or in the corners of the roof (pine needles are a common enough fuel source). At that point, you've got a far harder problem - direct flame impingement. If you get to that point, you are usually screwed. You can build fireproof roofs - I fully support pretty much anything in any areas requiring a Class A fireproof roof, which doesn't really mean much more than "being careful what you build, and not using wood shake." An asphalt shingle roof can often be Class A fireproof, and that tolerates a 2' x 2' bit of burning brand on the roof without burnthrough. The roof may not be in great shape, but an awful lot of "stuff on fire" can land on it, and if it's a properly constructed Class A roof, it won't penetrate to the building. The landscaping around the building is a harder problem. Within 30' or so, it generally has to "not burn." This can be from design, or from sprinklers, or... whatever. If the landscaping within 30' of a house is on fire, the house is likely to follow. If you keep that from lighting, the house stands a pretty good chance. ... yes, this means that in suburbia, if the house next door is on fire, you're screwed. Don't live in such tightly packed spaces. The next major problem are windows. If they fail, the house usually goes. They tolerate a lot, but in high wind storms, random debris can break the window, and then firebrands get in. Whoops. I would like to see some good studies on shutters, because they seem like the sort of thing that will make a very real difference on window breakage in storms, but they're not a thing anymore and probably won't come back. But look at the debris patterns when you find the news articles of the burned out neighborhoods. Almost always, you'll see intact lawns and vegetation around a burned out foundation. It's not a "wall of flame" marching through the neighborhood - it's the firebrands, blown by the wind, that you have to defend against. Unfortunately, when it comes to wildfires, when you've got things like 80 gusting 100, you're also just screwed. :/
  - mediocregopher 5y ago
- throwaway984393 5y ago
  Yeah failure from heat is one thing, but another is how quickly the structure catches fire or spreads it. Another commenter linked the 99PI piece how they found out that embers were getting through vents in roofs (you need those vents because your house is a weird little ecosystem) and catching the inside of the roof on fire. And if the outside is made of wood, it's more likely to catch than, say, concrete or brick. The material you're more likely to use for a home if it's not wood is concrete or brick with some steel added. Concrete and brick are very fire resistant, which would make it much harder for a building to catch, and so harder for fire to spread if the building doesn't catch. The reason our homes in the US aren't brick (anymore) is it's a very expensive/specialized job, but wood framing is easy in comparison and wood is cheap here (and we have a lot of lumber mills to churn out small standardized pieces) The inside would of course burn eventually if engulfed in a slow-moving fire with plenty of fuel, because things ignite when they get hot enough (or turn to charcoal if there's not enough oxygen). But if you're lucky the fire will move past quickly or run out of fuel, so every little advantage helps.
- dredmorbius 5y ago
  It's more the point that studs are not the key failure point of structures in the event of a fire. It's not that your studs are igniting and burning down the structure from inside the walls. It's that other structural elements are becoming engaged. Attic and crawlspaces especially, though also often porches, patios, and other extensions. See this IBHS wildfire structure ember test video: https://yewtu.be/watch?v=IvbNOPSYyss https://yewtu.be/watch?v=IvbNOPSYyss
rootusrootus 5y ago
AFAIK most structures destroyed in wildfires actually end up burning from the inside out. And roofs are rarely made from wood, it's mostly asphalt.
LukeShu 5y ago
> fire-prone areas This isn't in the foothills, where fires are expected. This is where no one expected a fire like this.
- dredmorbius 5y ago
  Expectations have now changed. This is, incidentally, a key issue in risk management: risk profiles and threat models are not a constant. The model is a reflection of reality, and if reality changes, the model should change with it.
deleted 5y ago
[deleted]

I'm wondering if fire-prone areas should be zoned to require fireproof building. No more wood homes/roofs. Europe generally doesn't use wood home construction, so doesn't seem crazy

gkop 5y ago

> if structures near fire-prone areas were designed and maintained to withstand fire, we might not need to fight some wildfires at all. https://99percentinvisible.org/episode/built-to-burn/ https://99percentinvisible.org/episode/built-to-burn/ I think you might be getting downvoted for "fireproof" which sounds absolute, and is probably not realistic. But you're right that regulations should evolve to require responsible home design and maintenance in fire-prone areas!

Syonyk 5y ago
++ for an article that mentions Jack Cohen. If you want to understand wildfires, read everything he's written. He's basically the single handed Mythbusters of wildfire understanding, and has done things like "instrumented crown fires of test stands" to better understand radiant heat flux from actual fires.

dntrkv 5y ago

I’m not an expert in the matter, but I’ve heard that modern wood frames are just as good as steel frames. If the fire is close and strong enough to ignite a wood stud, the steel stud would already fail. Though would love input from an expert here.

josephcsible 5y ago
Wouldn't the steel stud just structurally fail, rather than also becoming more fuel for the fire to spread to?
Syonyk 5y ago
Not an expert, but have done a lot of reading and some writing on wildfires, fire resistant structures, etc. I live on a hill that catches fire rather more often than I really enjoy and spend a lot of my spring cutting firebreaks. Any sort of structure, wood or not, will withstand a huge radiant flux of energy before catching fire. Well, well beyond what will crispy fry a human, the siding may be charred, but it won't burn. Even wood siding tolerates a lot. What lights houses on fire are firebrands - "burning crap from the sky." Trees, mostly, embers, other houses... that's what catches things. Typically it will light some small stuff near the house first, or in the corners of the roof (pine needles are a common enough fuel source). At that point, you've got a far harder problem - direct flame impingement. If you get to that point, you are usually screwed. You can build fireproof roofs - I fully support pretty much anything in any areas requiring a Class A fireproof roof, which doesn't really mean much more than "being careful what you build, and not using wood shake." An asphalt shingle roof can often be Class A fireproof, and that tolerates a 2' x 2' bit of burning brand on the roof without burnthrough. The roof may not be in great shape, but an awful lot of "stuff on fire" can land on it, and if it's a properly constructed Class A roof, it won't penetrate to the building. The landscaping around the building is a harder problem. Within 30' or so, it generally has to "not burn." This can be from design, or from sprinklers, or... whatever. If the landscaping within 30' of a house is on fire, the house is likely to follow. If you keep that from lighting, the house stands a pretty good chance. ... yes, this means that in suburbia, if the house next door is on fire, you're screwed. Don't live in such tightly packed spaces. The next major problem are windows. If they fail, the house usually goes. They tolerate a lot, but in high wind storms, random debris can break the window, and then firebrands get in. Whoops. I would like to see some good studies on shutters, because they seem like the sort of thing that will make a very real difference on window breakage in storms, but they're not a thing anymore and probably won't come back. But look at the debris patterns when you find the news articles of the burned out neighborhoods. Almost always, you'll see intact lawns and vegetation around a burned out foundation. It's not a "wall of flame" marching through the neighborhood - it's the firebrands, blown by the wind, that you have to defend against. Unfortunately, when it comes to wildfires, when you've got things like 80 gusting 100, you're also just screwed. :/
- mediocregopher 5y ago
throwaway984393 5y ago
Yeah failure from heat is one thing, but another is how quickly the structure catches fire or spreads it. Another commenter linked the 99PI piece how they found out that embers were getting through vents in roofs (you need those vents because your house is a weird little ecosystem) and catching the inside of the roof on fire. And if the outside is made of wood, it's more likely to catch than, say, concrete or brick. The material you're more likely to use for a home if it's not wood is concrete or brick with some steel added. Concrete and brick are very fire resistant, which would make it much harder for a building to catch, and so harder for fire to spread if the building doesn't catch. The reason our homes in the US aren't brick (anymore) is it's a very expensive/specialized job, but wood framing is easy in comparison and wood is cheap here (and we have a lot of lumber mills to churn out small standardized pieces) The inside would of course burn eventually if engulfed in a slow-moving fire with plenty of fuel, because things ignite when they get hot enough (or turn to charcoal if there's not enough oxygen). But if you're lucky the fire will move past quickly or run out of fuel, so every little advantage helps.
dredmorbius 5y ago
It's more the point that studs are not the key failure point of structures in the event of a fire. It's not that your studs are igniting and burning down the structure from inside the walls. It's that other structural elements are becoming engaged. Attic and crawlspaces especially, though also often porches, patios, and other extensions. See this IBHS wildfire structure ember test video: https://yewtu.be/watch?v=IvbNOPSYyss https://yewtu.be/watch?v=IvbNOPSYyss

rootusrootus 5y ago

AFAIK most structures destroyed in wildfires actually end up burning from the inside out. And roofs are rarely made from wood, it's mostly asphalt.

LukeShu 5y ago

> fire-prone areas This isn't in the foothills, where fires are expected. This is where no one expected a fire like this.

dredmorbius 5y ago
Expectations have now changed. This is, incidentally, a key issue in risk management: risk profiles and threat models are not a constant. The model is a reflection of reality, and if reality changes, the model should change with it.

deleted 5y ago

[deleted]