9 ms·

In US in many areas the earthquakes safety requires to build lighter houses. Plus many areas are subject to tornados and hurricanes when it is rather pointless

In US in many areas the earthquakes safety requires to build lighter houses. Plus many areas are subject to tornados and hurricanes when it is rather pointless to build anything that lasts 100 years. On that time scale the house will be destroyed or badly damaged in any case.

manmal 5y ago
Please bear in mind that I don’t mean the following in a cynic way. Damage from storms is horrible, and I feel for the families losing their homes every year. There was a tornado just a few days ago in the Czech Republic (not far from where I live), and as far as I can see, houses did lose their roofs, or the shingles at least, but the structures remained mostly intact. Many houses have basements in which people could hide in relative safety. Five people died unfortunately, not sure how many of those were in their homes at the time. But I think those rather sturdy houses made of bricks did infact save a lot of lives, and prevented many more from totally losing their home. To me it feels deeply illogical to build a house basically made of light wood frames when I know a hurricane can blow it away while I‘m inside of it. I‘m not sure about earthquakes, we have them of course, but they are less severe than in other areas in the world.
- strstr 5y ago
  The frequency and maximum strength of tornadoes are higher in the central US. Casual skim of the wikipedia page indicates about as many F4 tornadoes in Europe as F5 tornadoes in the US since 2000.
- octopoc 5y ago
  There are many tornadoes where I live and most of the houses don’t have basements. Directly in the path of the tornado, houses built on a slab were completely gone, leaving only a clean slab. This happened to a few entire neighborhoods. But, tornadoes here follow similar paths over a fifty year period. When I bought my house I found a hole in the fifty year tornado map and I’ve never had one come near me. Every couple decades the patterns may shift to other patterns, but generally speaking both the new patterns and old patterns have all happened in the last fifty years.
  - manmal 5y ago
    That’s devastating. I wonder why houses in such areas are not required to provide underground shelter, or at least be built more solidly.
    - ghaff 5y ago
      You cannot reasonably build solidly enough to withstand a high-level tornado unless you're talking underground bunkers, which are not an acceptable answer.
      - manmal 5y ago
        That’s a bit defeatist, though? Efforts have been made, eg https://tigerprints.clemson.edu/cgi/viewcontent.cgi?article=4102&context=all_theses https://tigerprints.clemson.edu/cgi/viewcontent.cgi?article=... It seems a concrete dome would also work if digging a bunker is too expensive. Yes it’s not pretty, but not being afraid of dying during the next hurricane season must be worth something. A small dome can’t cost much.
        ghaff 5y ago
        Sure. Building a reinforced shelter for tornadoes, nuclear attack, etc. may make sense. Historically, in the US Midwest that meant going into the basement. But you don't live there.
      - bobthepanda 5y ago
        Is it not? For a few decades the Swiss required building concrete nuclear fallout bunkers for every resident. This was relaxed only recently, but presumably it was doable for five decades. https://www.reuters.com/article/us-swiss-bunker/swiss-relax-nuclear-shelter-construction-law-idUSTRE7B01RP20111201 https://www.reuters.com/article/us-swiss-bunker/swiss-relax-...
        ghaff 5y ago
        So you can be in a bunker above ground. At that point you're quibbling.
- crooked-v 5y ago
  I just looked that up and that appears to have been an EF2 tornado. That intensity deals an order of magnitude less damage than the EF3, EF4, and EF5 tornadoes that regularly appear in the US, which can literally tear entire houses off their foundations. A brick building in those conditions would be reduced to individual bricks.
  - manmal 5y ago
    I read it was estimated to be F4. Brick houses are definitely less likely to be destroyed than timber.
    - syoc 5y ago
      Timber can be many things. I have a hard time seeing a log house being swept away by almost any force of wind.
      - TylerE 5y ago
        Then you don't appreciate the forces at play. An EF4 will rip deep rooted trees right out of the ground.
        syoc 5y ago
        I can see that there are manufacturers selling log houses certified for cat-5 (245 mph) hurricanes. I do of course understand that any construction will be blown away at some point, I just cant picture it. The way the logs lock each other at the intersections and how the structure still is sound with no roof should help quite a bit.
        TylerE 5y ago
        The big danger in a cat 5 is more the debris. There's a saying: It's not THAT the wind is blowing,it's WHAT the wind is blowing.
      - mythrwy 5y ago
- coryrc 5y ago
  Insurance is federally subsidized/backstopped so people in hurricane or tornado zones don't have to pay for repairs directly, so it's cheaper to build a junk house than one which wouldn't take damage.
- jaclaz 5y ago
  Well, the three little pigs story must have been originated somehow from real life experience: https://en.wikipedia.org/wiki/The_Three_Little_Pigs https://en.wikipedia.org/wiki/The_Three_Little_Pigs
Ericson2314 5y ago
I lived in a wooden house with a brick facade from 1905 in San Francisco, so I think this is overstated. They have earthquakes in e.g. Italy and Turkey too, you know.
- fpoling 5y ago
  On my visit to SF I saw a warning an a building that it did not satisfy earthquake safety standards of the government of California. A colleague explained that this was a common thing with old buildings in SF.
estaseuropano 5y ago
I don't want to doubt you, but this sounds like 'folk wisdom' or 'common sense' logic, rather than fact. You are not seriously claiming that every piece of land is hit by earthquakes or hurricanes once every 50 years? While they get lots of attention my guess would be this is a shark attack-like phenomenon: its so unusual that its news worthy, which is why people think it is more frequent than it is. There are certainly earthquake (and hurricane) areas but the majority of the US population does not live in those. I'd need some risk/benefit analysis and actual data before believing they are even a factor in the equation for most people and areas. I can think of 100 other possible reasons (eg historically people moved frequently, or it was simply cheaper to rebuild than maintain as building standards/expectations change frequently, or in the cities you anyway expect someone to come in and buy up old building stock and rip it all down to put something bigger in, or ... ).
- Enginerrrd 5y ago
  OP is exaggerating a bit, but mostly spot on. There's a wealth of information this. See ASCE 7-16 Minimum Design Loads and Associated Criteria for Buildings and Other Structures, For wind: Chapters 26-31 for 144 pages of wind load design criteria. (California Building Code and International Building Codes recognize and point to that standard) Of particular note, is a concept called "Basic Wind Speed" which is derived from mapped values. What you'll find is that its intimately correlated with hurricane landing. Most people live on the coast in the US where the wind speed is highest. Depending on the risk category of the building, a typical value on the West coast is ~105 mph. On the east coast, it vaires by latitude from ~115-200 mph, increasing in all the areas that get hit by hurricanes. To address your skepticism, I assure you things like hurricanes are undeed a significant design concern. The seismic load is similar. Both loads are fundamentally designed to give a defined risk of failure from storms and earthquakes with particular recurrence intervals ranging from 50-100 years. (Offhand, I believe this value is ~1% for total collapse with a much higher risk of damage.). It is indeed carefully weighted and considered balance between risk reduction and feasibility, and indeed, having less than 1% risk for intervals over 100 years starts to get rather difficult. We still require it for schools, police stations, and emergency gathering locations and the like, but not normal houses.
mcguire 5y ago
"Atlanta has seen 77 tornadoes in the four counties of Clayton, Cobb, Dekalb and Fulton from 1950-2013. This is a density of 0.94 tornadoes per year per 1,000 square miles." 1,000 sq mi is about 640,000 acres, so that's .0000015 tornadoes per year per acre. If I've got my math right, that's about a 99.9% chance that your 1 acre plot will not be hit by a tornado in 1000 years, if you live in the Atlanta area, which is only a middling high-probability area. (https://weather.com/storms/tornado/news/tornado-odds-of-being-hit https://weather.com/storms/tornado/news/tornado-odds-of-bein...) Hurricanes are generally only a coastal problem, although flooding is a fairly large issue everywhere. (Don't get a house in a low lying area. Please.) Earthquakes are mostly a West Coast thing, modulo New Madrid (pronounced "mad-rid") and various oil drilling operations. But then there's fires and termites and everything else. There are plenty of hundred-year-old houses all over the US, as well as plenty of newer ones that could last more than a century with proper maintenance. Few houses today are built to last that long, though, because it's more expensive but doesn't add anything to the purchase price like granite countertops. Stick frame on slab construction is pretty close to mini-maxing housing construction as the article describes (even in areas where slab foundations are geologically idiotic). Anyway, when you get down to the second-to-last section of the article, remember that, past a certain point, efficiency is the enemy of resiliency.
- nkurz 5y ago
  > 1,000 sq mi is about 640,000 acres, so that's .0000015 tornadoes per year per acre. If I've got my math right, that's about a 99.9% chance that your 1 acre plot will not be hit by a tornado in 1000 years I appreciate your attempt to come up with realistic numbers, but you are making the assumption that each tornado only affects a single acre. As discussed in the article you linked, if a tornado touches down, it frequently causes destruction for a path of several miles, making this a faulty assumption.
axiolite 5y ago
> In US in many areas the earthquakes safety requires to build lighter houses. A lighter building does not protect you from earthquakes. Less-brittle materials, much more securely fastened together is what you want. With wood building this means metal strapping around studs nailed in perpendicular to the forces. With masonry buildings it means a lot of steel to hold the everything together. > Plus many areas are subject to tornados and hurricanes when it is rather pointless to build anything that lasts 100 years. On that time scale the house will be destroyed or badly damaged in any case. Tornadoes yes, hurricanes, no. Build strong and heavy, with durable steel shutters for all windows and very secure doors, and there's no reason your home can't survive hurricanes with minimal damage. Flooding is another matter, entirely.

manmal 5y ago

Please bear in mind that I don’t mean the following in a cynic way. Damage from storms is horrible, and I feel for the families losing their homes every year. There was a tornado just a few days ago in the Czech Republic (not far from where I live), and as far as I can see, houses did lose their roofs, or the shingles at least, but the structures remained mostly intact. Many houses have basements in which people could hide in relative safety. Five people died unfortunately, not sure how many of those were in their homes at the time. But I think those rather sturdy houses made of bricks did infact save a lot of lives, and prevented many more from totally losing their home. To me it feels deeply illogical to build a house basically made of light wood frames when I know a hurricane can blow it away while I‘m inside of it. I‘m not sure about earthquakes, we have them of course, but they are less severe than in other areas in the world.

strstr 5y ago
The frequency and maximum strength of tornadoes are higher in the central US. Casual skim of the wikipedia page indicates about as many F4 tornadoes in Europe as F5 tornadoes in the US since 2000.
octopoc 5y ago
There are many tornadoes where I live and most of the houses don’t have basements. Directly in the path of the tornado, houses built on a slab were completely gone, leaving only a clean slab. This happened to a few entire neighborhoods. But, tornadoes here follow similar paths over a fifty year period. When I bought my house I found a hole in the fifty year tornado map and I’ve never had one come near me. Every couple decades the patterns may shift to other patterns, but generally speaking both the new patterns and old patterns have all happened in the last fifty years.
- manmal 5y ago
  That’s devastating. I wonder why houses in such areas are not required to provide underground shelter, or at least be built more solidly.
  - ghaff 5y ago
    You cannot reasonably build solidly enough to withstand a high-level tornado unless you're talking underground bunkers, which are not an acceptable answer.
    - manmal 5y ago
      That’s a bit defeatist, though? Efforts have been made, eg https://tigerprints.clemson.edu/cgi/viewcontent.cgi?article=4102&context=all_theses https://tigerprints.clemson.edu/cgi/viewcontent.cgi?article=... It seems a concrete dome would also work if digging a bunker is too expensive. Yes it’s not pretty, but not being afraid of dying during the next hurricane season must be worth something. A small dome can’t cost much.
      - ghaff 5y ago
        Sure. Building a reinforced shelter for tornadoes, nuclear attack, etc. may make sense. Historically, in the US Midwest that meant going into the basement. But you don't live there.
    - bobthepanda 5y ago
      Is it not? For a few decades the Swiss required building concrete nuclear fallout bunkers for every resident. This was relaxed only recently, but presumably it was doable for five decades. https://www.reuters.com/article/us-swiss-bunker/swiss-relax-nuclear-shelter-construction-law-idUSTRE7B01RP20111201 https://www.reuters.com/article/us-swiss-bunker/swiss-relax-...
      - ghaff 5y ago
        So you can be in a bunker above ground. At that point you're quibbling.
crooked-v 5y ago
I just looked that up and that appears to have been an EF2 tornado. That intensity deals an order of magnitude less damage than the EF3, EF4, and EF5 tornadoes that regularly appear in the US, which can literally tear entire houses off their foundations. A brick building in those conditions would be reduced to individual bricks.
- manmal 5y ago
  I read it was estimated to be F4. Brick houses are definitely less likely to be destroyed than timber.
  - syoc 5y ago
    Timber can be many things. I have a hard time seeing a log house being swept away by almost any force of wind.
    - TylerE 5y ago
      Then you don't appreciate the forces at play. An EF4 will rip deep rooted trees right out of the ground.
      - syoc 5y ago
        I can see that there are manufacturers selling log houses certified for cat-5 (245 mph) hurricanes. I do of course understand that any construction will be blown away at some point, I just cant picture it. The way the logs lock each other at the intersections and how the structure still is sound with no roof should help quite a bit.
        TylerE 5y ago
        The big danger in a cat 5 is more the debris. There's a saying: It's not THAT the wind is blowing,it's WHAT the wind is blowing.
    - mythrwy 5y ago
coryrc 5y ago
Insurance is federally subsidized/backstopped so people in hurricane or tornado zones don't have to pay for repairs directly, so it's cheaper to build a junk house than one which wouldn't take damage.
jaclaz 5y ago
Well, the three little pigs story must have been originated somehow from real life experience: https://en.wikipedia.org/wiki/The_Three_Little_Pigs https://en.wikipedia.org/wiki/The_Three_Little_Pigs

Ericson2314 5y ago

I lived in a wooden house with a brick facade from 1905 in San Francisco, so I think this is overstated. They have earthquakes in e.g. Italy and Turkey too, you know.

fpoling 5y ago
On my visit to SF I saw a warning an a building that it did not satisfy earthquake safety standards of the government of California. A colleague explained that this was a common thing with old buildings in SF.

estaseuropano 5y ago

I don't want to doubt you, but this sounds like 'folk wisdom' or 'common sense' logic, rather than fact. You are not seriously claiming that every piece of land is hit by earthquakes or hurricanes once every 50 years? While they get lots of attention my guess would be this is a shark attack-like phenomenon: its so unusual that its news worthy, which is why people think it is more frequent than it is. There are certainly earthquake (and hurricane) areas but the majority of the US population does not live in those. I'd need some risk/benefit analysis and actual data before believing they are even a factor in the equation for most people and areas. I can think of 100 other possible reasons (eg historically people moved frequently, or it was simply cheaper to rebuild than maintain as building standards/expectations change frequently, or in the cities you anyway expect someone to come in and buy up old building stock and rip it all down to put something bigger in, or ... ).

Enginerrrd 5y ago
OP is exaggerating a bit, but mostly spot on. There's a wealth of information this. See ASCE 7-16 Minimum Design Loads and Associated Criteria for Buildings and Other Structures, For wind: Chapters 26-31 for 144 pages of wind load design criteria. (California Building Code and International Building Codes recognize and point to that standard) Of particular note, is a concept called "Basic Wind Speed" which is derived from mapped values. What you'll find is that its intimately correlated with hurricane landing. Most people live on the coast in the US where the wind speed is highest. Depending on the risk category of the building, a typical value on the West coast is ~105 mph. On the east coast, it vaires by latitude from ~115-200 mph, increasing in all the areas that get hit by hurricanes. To address your skepticism, I assure you things like hurricanes are undeed a significant design concern. The seismic load is similar. Both loads are fundamentally designed to give a defined risk of failure from storms and earthquakes with particular recurrence intervals ranging from 50-100 years. (Offhand, I believe this value is ~1% for total collapse with a much higher risk of damage.). It is indeed carefully weighted and considered balance between risk reduction and feasibility, and indeed, having less than 1% risk for intervals over 100 years starts to get rather difficult. We still require it for schools, police stations, and emergency gathering locations and the like, but not normal houses.

mcguire 5y ago

"Atlanta has seen 77 tornadoes in the four counties of Clayton, Cobb, Dekalb and Fulton from 1950-2013. This is a density of 0.94 tornadoes per year per 1,000 square miles." 1,000 sq mi is about 640,000 acres, so that's .0000015 tornadoes per year per acre. If I've got my math right, that's about a 99.9% chance that your 1 acre plot will not be hit by a tornado in 1000 years, if you live in the Atlanta area, which is only a middling high-probability area. (https://weather.com/storms/tornado/news/tornado-odds-of-being-hit https://weather.com/storms/tornado/news/tornado-odds-of-bein...) Hurricanes are generally only a coastal problem, although flooding is a fairly large issue everywhere. (Don't get a house in a low lying area. Please.) Earthquakes are mostly a West Coast thing, modulo New Madrid (pronounced "mad-rid") and various oil drilling operations. But then there's fires and termites and everything else. There are plenty of hundred-year-old houses all over the US, as well as plenty of newer ones that could last more than a century with proper maintenance. Few houses today are built to last that long, though, because it's more expensive but doesn't add anything to the purchase price like granite countertops. Stick frame on slab construction is pretty close to mini-maxing housing construction as the article describes (even in areas where slab foundations are geologically idiotic). Anyway, when you get down to the second-to-last section of the article, remember that, past a certain point, efficiency is the enemy of resiliency.

nkurz 5y ago
> 1,000 sq mi is about 640,000 acres, so that's .0000015 tornadoes per year per acre. If I've got my math right, that's about a 99.9% chance that your 1 acre plot will not be hit by a tornado in 1000 years I appreciate your attempt to come up with realistic numbers, but you are making the assumption that each tornado only affects a single acre. As discussed in the article you linked, if a tornado touches down, it frequently causes destruction for a path of several miles, making this a faulty assumption.

axiolite 5y ago

> In US in many areas the earthquakes safety requires to build lighter houses. A lighter building does not protect you from earthquakes. Less-brittle materials, much more securely fastened together is what you want. With wood building this means metal strapping around studs nailed in perpendicular to the forces. With masonry buildings it means a lot of steel to hold the everything together. > Plus many areas are subject to tornados and hurricanes when it is rather pointless to build anything that lasts 100 years. On that time scale the house will be destroyed or badly damaged in any case. Tornadoes yes, hurricanes, no. Build strong and heavy, with durable steel shutters for all windows and very secure doors, and there's no reason your home can't survive hurricanes with minimal damage. Flooding is another matter, entirely.