TR Forums

...and in "Tornado Alley" there isn't really much you can do to tornado-proof a house unless you are willing to live in a Cold War era underground missile silo. Tornadoes are smaller than hurricanes in terms of area, but unimaginably powerful where they touch down. Brick exterior walls will provide some protection from blowing debris if a tornado passes nearby, but won't stand up to a direct hit; if you're inside a brick home when it gets hit by a tornado, in all likelihood you'll literally be buried alive under a ton of bricks.

Tornadoes suck and a proper shelter cost 6-10 grand to install But they will keep you safe.

Frankly, the real danger from tornadoes comes from lack of warning; a hurricane you get at least a few days. Tornadoes if you're lucky you get a few minutes. But a bad hurricane can be just as destructive as a bad tornado, between the water and the wind; I've been to Galveston post-Rita (visiting my folks after the storm, thsi was before my current job) and it was amazing to see the boats and cars just tossed around lying on city streets and in some cases in the middle of houses. Hell, even Ike took out a lot of my parents house and they were 60+ miles inland at that point.

I'm kind of wandering if the affected local agencies will be asking for people to come in from nationwide at this. I'm pretty sure they don't have a lot of experience with hurricanes up there.

just brew it! wrote:

...and in "Tornado Alley" there isn't really much you can do to tornado-proof a house unless you are willing to live in a Cold War era underground missile silo. Tornadoes are smaller than hurricanes in terms of area, but unimaginably powerful where they touch down. Brick exterior walls will provide some protection from blowing debris if a tornado passes nearby, but won't stand up to a direct hit; if you're inside a brick home when it gets hit by a tornado, in all likelihood you'll literally be buried alive under a ton of bricks.

The good news is that tornadoes tend to be random, so even if they hit a neighborhood, most houses won't take direct hits. The biggest concern in that case is the flying debris. Even if your house isn't directly hit by the tornado, it will probably get hit by whatever gets picked up and thrown. What's worse, the stronger the twister, the larger the projectiles...

superjawes wrote:

What's worse, the stronger the twister, the larger the projectiles...

Yup. I remember seeing a video a few months back of a tornado tossing semi trailers around like toys. I imagine not many homes would survive having a semi trailer dropped on them from a great height.

You can also wind up with hurricanes spawning tornadoes; and of course the weather conditions that are good for tornadoes can cause more than one (they tend to occur in clusters). Fun times.

Arclight wrote:

JohnC wrote:

Well... it appears that we may be screwed on Monday:[...]

Unlike in Florida, our flimsy matchstick houses here in NY aren't really designed to be "hurricane-proof"...

I always wondered why US houses are so flimsy.....especially in areas affected by tornados and hurricans. Why not make them out of sturdy materials? If not do something innovative like dom houses or something. Do you really prefer just to rebuild every time?

Define "flimsy". I can show you some 3-story, wood-frame apartment homes that have withstood sustained 30-40mph winds with 90mph gusts, and been subjected to nothing worse than lost siding and shingles. But place one of those same buildings under a direct hit from an F2+ tornado and half or more of it will disappear into matchsticks.

Back in summer 2011, an electrical substation in Oklahoma took a direct hit from a supercell tornado which, IIRC, evolved into an F3 as it progressed. An engineer at our company received aftermath photos from a business acquaintance in the area. The entire substation was leveled, and that included an oil filled power transformer which probably weighing in excess of 100,000 pounds (45,000 kg), which was ripped clean from its concrete foundation, shearing the anchor bolts, and thrown on its side several feet away. Nearly all of the substation steel, which presents very little surface area and would have weighed in at perhaps 5,000-15,000 pounds per structure and been bolted to concrete foundations, was down as well.

The only practical structure that can withstand those sorts of forces and not take critical damage is a subterranean cave. Otherwise, you're talking in terms of steel-reinforced concrete structures with foundations constructed of drilled piers or massive steel bolts into bedrock, when bedrock is located at a practical depth, all for a one-in-a-million chance of being hit by a freak act of nature...at a cost of 50-100 times an ordinary home price. In other news, it is technically possible to build homes that are completely fireproof, but nobody does it, for similar reasons. Better to just use good wiring practice, keep fire extinguishers handy, maybe install an active fire suppression system in some cases where the risk outweighs the cost...and carry a good homeowner's insurance policy.

Visible loop of Hurricane Sandy:
http://rammb.cira.colostate.edu/templat ... display=50

ludi wrote:

The only practical structure that can withstand those sorts of forces and not take critical damage is a subterranean cave. Otherwise, you're talking in terms of steel-reinforced concrete structures with foundations constructed of drilled piers or massive steel bolts into bedrock, when bedrock is located at a practical depth, all for a one-in-a-million chance of being hit by a freak act of nature...at a cost of 50-100 times an ordinary home price. In other news, it is technically possible to build homes that are completely fireproof, but nobody does it, for similar reasons. Better to just use good wiring practice, keep fire extinguishers handy, maybe install an active fire suppression system in some cases where the risk outweighs the cost...and carry a good homeowner's insurance policy.

On a side note, you sometimes hear about restaurant workers who survive a tornado by taking shelter in a walk-in freezer. But this doesn't protect from a direct hit; a direct hit would completely shred the freezer and its contents. What the freezer *does* do is provide some protection from flying and falling debris.

just brew it! wrote:

On a side note, you sometimes hear about restaurant workers who survive a tornado by taking shelter in a walk-in freezer. But this doesn't protect from a direct hit; a direct hit would completely shred the freezer and its contents. What the freezer *does* do is provide some protection from flying and falling debris.

A walk-in freezer might be okay from a direct hit since it has a building around it. Sure, there would be lots of damage to the building, but it could also disrupt the airflow, essentially preventing the tornado from getting under the freezer like it would a standalone structure (or a car).

But, again, depends on the storm.

Tornadoes can just pick up entire buildings and deposit them elsewhere. I've seen first-hand a house that it picked up off the foundation, spun it 90 degrees, and set it right back down. Fortunately the owners weren't home. I don't think a structure that would be "okay from a direct hit" exists.

derFunkenstein wrote:

Tornadoes can just pick up entire buildings and deposit them elsewhere. I've seen first-hand a house that it picked up off the foundation, spun it 90 degrees, and set it right back down. Fortunately the owners weren't home. I don't think a structure that would be "okay from a direct hit" exists.

What about flats? I never watched that many tornado aftermath videos (mostly i've seen on the Discovery channel), but concrete structures like flat apartments are also as affected as normal wood or brick homes? I presume they shouldn't but i'd like some images to show the contrary.

Arclight wrote:

derFunkenstein wrote:

Tornadoes can just pick up entire buildings and deposit them elsewhere. I've seen first-hand a house that it picked up off the foundation, spun it 90 degrees, and set it right back down. Fortunately the owners weren't home. I don't think a structure that would be "okay from a direct hit" exists.

What about flats? I never watched that many tornado aftermath videos (mostly i've seen on the Discovery channel), but concrete structures like flat apartments are also as affected as normal wood or brick homes? I presume they shouldn't but i'd like some images to show the contrary.

I'm not sure. But a really strong tornado can hurl projectiles with enough force that they will penetrate solid concrete, so your concrete structures will sustain at least some damage.

Arclight wrote:

What about flats? I never watched that many tornado aftermath videos (mostly i've seen on the Discovery channel), but concrete structures like flat apartments are also as affected as normal wood or brick homes? I presume they shouldn't but i'd like some images to show the contrary.

Living in Oklahoma, I can't think of any apartment complexes that are made from just concrete, they're usually made from the same materials as traditional homes. With that being said, apartments are usually one of the worst places to be (next to a trailer park) during a tornado.

Dizik wrote:

Arclight wrote:

What about flats? I never watched that many tornado aftermath videos (mostly i've seen on the Discovery channel), but concrete structures like flat apartments are also as affected as normal wood or brick homes? I presume they shouldn't but i'd like some images to show the contrary.

Living in Oklahoma, I can't think of any apartment complexes that are made from just concrete, they're usually made from the same materials as traditional homes. With that being said, apartments are usually one of the worst places to be (next to a trailer park) during a tornado.

No i wasn't talking about where to shelter yourself during a tornado, rather i was wondering why people don't contruct buildings capable of withstanding tornados and just repair the damages from impact with debrees.

Idk how buildings are constructed there, but the fact that you say "Living in Oklahoma, I can't think of any apartment complexes that are made from just concrete" makes me even more curious as to why you have such flimsy buildings.

@jbi
That's not reinforced concrete that should be used for buildings....depending on the recipe. the concrete can vary a lot in strength, durability etc. That pic shows some wood chips going through the concrete without breaking, to me it looks like concrete wasn't even dried. But that's not the point, my point being that due to it's destination that concrete will not have the same chracteristics as the concrete (meaning a different recipe with a different mixture of ciment, aggregates etc.) used for buildings and neither will it be as strong as reinforced concrete.

Arclight wrote:

Idk how buildings are constructed there, but the fact that you say "Living in Oklahoma, I can't think of any apartment complexes that are made from just concrete" makes me even more curious as to why you have such flimsy buildings.

As someone else posted above, it's mainly a cost thing. Given that the risk of any individual structure being hit by a tornado over its lifetime is very small, and the cost of making a structure "tornado proof" very high, it just isn't economically viable.

just brew it! wrote:

Arclight wrote:

Idk how buildings are constructed there, but the fact that you say "Living in Oklahoma, I can't think of any apartment complexes that are made from just concrete" makes me even more curious as to why you have such flimsy buildings.

As someone else posted above, it's mainly a cost thing. Given that the risk of any individual structure being hit by a tornado over its lifetime is very small, and the cost of making a structure "tornado proof" very high, it just isn't economically viable.

I can only compare to what i know. Where i live in Europe we don't experience tornados but we do have earthquakes and floods and even though you say it's not economically viable i've seen buildings far more durable in small cities here than the flimsy structures described by the posters, or what i've seen on the news or on Discovery channel.

Be it economy or tradition, to me as an European, i find most of American houses and small buildings designed for housing, to be weak, especialy because they are exposed to extreme natural disasters like tornados.

Arclight wrote:

I can only compare to what i know. Where i live in Europe we don't experience tornados but we do have earthquakes and floods and even though you say it's not economically viable i've seen buildings far more durable in small cities here than the flimsy structures described by the posters, or what i've seen on the news or on Discovery channel.

Be it economy or tradition, to me as an European, i find most of American houses and small buildings designed for housing, to be weak, especialy because they are exposed to extreme natural disasters like tornados.

Yes, I suppose there's a bit of tradition (or lack thereof) involved as well. Residential structures here typically aren't built with the intent of having them last hundreds of years. Unlike in Europe, a 100+ year old structure (of *any* type) is considered rather old.

If some of your durable buildings dealt with even an F3 I don't know if they'd still be standing. Or a large cat 3 storm.

paulWTAMU wrote:

If some of your durable buildings dealt with even an F3 I don't know if they'd still be standing. Or a large cat 3 storm.

I'm not asking for miracles, just a picture of a multi level concrete building that dealt with an F3.......I very much doubt it would be completly leveled or moved off of it's foundation. I expect windows destroyed, debris stuck in walls and maybe a damaged facade but nothing that would structurly compromise it. Prove me wrong, i can take it.

As requested. Did you show up halfway through the thread, or do you have a terrible short-term memory?

And just so we're clear: the gist of your argument is "we don't have any tornadoes, but we have floods and we can build buildings that are flood proof, so you can build buildings that are tornado proof". Do you see the problem with that line of reasoning?

Arclight wrote:

Where i live in Europe we don't experience tornados but we do have earthquakes and floods...

Well there's a problem.

Floods are probably more damaging than tornadoes, but it's not very expensive to handle a flood provided that you have levees on your rivers that are likely to flood. You can also simply raise the living floors in an apartment complex so that parking structures flood, leaving the living spaces relatively safe.

Making a structure "earthquake-proof" doesn't mean that your building is sturdy, either. In fact, you want the interface bewteen the structure and the foundation to act as a shock absorber (some flexibility) so that the building gets shaken around without cracking the solid materials (like concrete and brick).

Now here's the thing...if you raise the structure, you're not any more tornado-proof. Tornado-proofing a building inheirently makes it less safe for an earthquake, since the structure will have to be made out of more solid, heavy materials with rigid foundations.

I'll also add that, especially here in the US, the soil you lay your foundation on also makes a difference. In Oklahoma and Texas, for example, the soil is a clay that can dry out in summer months. People in those states actually water their foundations so that houses don't simply break off.

EDIT: Another angle I forgot...Tornado Alley has a lot of land, the population density is very low, and property is fairly cheap, meaning that you can get two or three houses in a place like Texas for the same that you would spend on one house in the Chicagoland area. Low property costs is one of the perks of living in these states, and building a giant, concrete house could nullify that advantage. Now pair that with the relatively low risk of getting directly hit by a tornado, and it's a very poor value proposition to build something that sturdy. Even if you factor in flying projectiles, your typical tornado will only leave scratches and broken windows (easy repairs), and your stronger tornadoes are rarer and even harder to perdict and plan for.

grantmeaname wrote:

As requested. Did you show up halfway through the thread, or do you have a terrible short-term memory?

And just so we're clear: the gist of your argument is "we don't have any tornadoes, but we have floods and we can build buildings that are flood proof, so you can build buildings that are tornado proof". Do you see the problem with that line of reasoning?

.........sigh
Since we have the natural disasters listed we prepared for them so why don't you prepare for your natural disasters? That's what i'm saying....
What you described are not buildings. How heavy do you think a few levels high building made from reinforced concrete really is? Certainly more than 45 tones and certainly far better connected to the foundation than a few bolts. Still waiting on proof, just googled some images and they show what i expected.

paulWTAMU wrote:

Because making a building able to deal with isn't cost effective.

Yes it's more expensive but it will last longer.

Because making a building able to deal with isn't cost effective.

Let me put it this way:

You have no damn idea what you're talking about. You do not have hurricanes/typhoons in your region. You don't have tornadoes. You're drawing conclusions that are totally erroneous. You can build buildings to withstand some natural disasters much easier than you can build them to withstand other natural disasters. And scope matters too; withstanding a cat 1 hurricane isn't a big deal (and plenty of homes do it, regularly). Withstanding a cat 3-5? That's a whole different story. Then you factor in different flood tables during storms of comparable wind speed and that makes it even more complicated. If you're in a 500 year flood plain, why build a house that's safe for a 500 year fold? Odds are good it wouldn't last that long anyway. Most of the US goes decades if not generations between big storm events like this.

Have you SEEN what you have to do to make a tornado shelter able to survive an F3 or F4? You do, very much, need a bunker. That's basically what a *good* tornado shelter is. My in-laws have one that's essentially a 10x10 box buried in the ground with access through a door in the garage floor and a couple of ventilation pipes. Total cost to install was something like 15 grand. For a 10x10 box with no power, plumbing, etc.

Floods are probably more damaging than tornadoes, but it's not very expensive to handle a flood provided that you have levees on your rivers that are likely to flood. You can also simply raise the living floors in an apartment complex so that parking structures flood, leaving the living spaces relatively safe.

I would say MOST tornadoes are not as damaging as a big flood, but that's got more to do with the area covered by a flood. But ask the folks in Happy how bad a big tornado can be. Or Joplin. I have friends that live in Happy--it's about 20 miles away from me, and I've talked with people in my field that went through Joplin in the recovery, mostly trading ideas about what works and what doesn't regarding planning and prep. Tornadoes saving grace is that the effects are usually very localized; they're incredibly destructive where they touch though.

My house narrowly escaped the biggest tornado ever recorded during the May 3, 1999 outbreak in Oklahoma. For those of you unfamiliar with those storms, the main tornado had winds exceeding 300 mph (482+ kph) and the destruction was in the truest sense of the word, awesome. The tornado was so strong and so destructive, that there were talks of classifying it as the first F-6 tornado. Anything and everything that was in the direct path of that tornado was destroyed, regardless of its construction. My guess is that even concrete buildings were destroyed because the tornado was throwing cars, trucks, and houses at them. Yes, tornadoes as large as the May 3rd tornado are extremely rare, but they do (obviously) happen. And to build everything out of materials strong enough to handle storms of that magnitude are not only insanely cost prohibitive, but what do you do to the existing homes and businesses? Do you force everybody out of their home because they don't meet construction ordinances? If so, where are those people going to live and work now? Are we going to have to raise an ungodly amount of tax dollars to build new homes for the vast majority of the population that can't afford to build a new house?

So to say "just make everything out of concrete, and you'll be fine" is ludicrous. Hell, we're having trouble getting funding to provide tax rebates and vouchers to build new storm shelters.

Arclight wrote:

Be it economy or tradition, to me as an European, i find most of American houses and small buildings designed for housing, to be weak, especialy because they are exposed to extreme natural disasters like tornados.

Yes, well, that's what happens when large portions of your continent were deforested by Romans roughly 2000 years ago for fuel and shipbuilding, then deforested again 250 years ago by the Industrial revolution. Meanwhile, manual laborers were available and cheap, so off to the stone quarries they go. Everything is built of stone and stays up for 500+ years because that was what was available to build, and for the most part, Europe doesn't experience the kind of natural disasters that destroy stone buildings. However, you may not know the history of your own continent -- historically, there have been a few severe earthquakes and they have been devastating, because although mortared stone structures are excellent for static loading and can endure for centuries under ordinary weather, they do not handle shaking very well.

[fixed the quote for you --JBI]

The easiest thing to do when building a new home is to have a walk-in closet with reinforced concrete walls, a metal door and a steel plate ceiling. That way, if the whole house is blown away, you're still okay in the safe room / tornado shelter. The cost for this sort of addition might be in the ballpark of $5k for new construction or more than double that for modifications to an existing home.

JustAnEngineer wrote:

The easiest thing to do when building a new home is to have a walk-in closet with reinforced concrete walls, a metal door and a steel plate ceiling. That way, if the whole house is blown away, you're still okay in the safe room / tornado shelter. The cost for this sort of addition might be in the ballpark of $5k for new construction or more than double that for modifications to an existing home.

Alternatively, one could just buy a house with a basement.

Vrock wrote:

JustAnEngineer wrote:

The easiest thing to do when building a new home is to have a walk-in closet with reinforced concrete walls, a metal door and a steel plate ceiling. That way, if the whole house is blown away, you're still okay in the safe room / tornado shelter. The cost for this sort of addition might be in the ballpark of $5k for new construction or more than double that for modifications to an existing home.

Alternatively, one could just buy a house with a basement.

...and have the whole house fall in on your head when the tornado hits.

just brew it! wrote:

...and have the whole house fall in on your head when the tornado hits.

Hmm, living here in VT where cellars are simply assumed to be part of a house vs. ground level tornado shelters.

I understand why most of the Midwest is on slab; the ground is a rock. Up here I'd not want to be under my 1875 structure in a big blow.