Designing a house in tornado-ridden places

[Mr. Man-wai Chang]

Why are they still using wood? Can't they move their expensive equipment to basement before leaving their homes?

It just does not make sense.... Remember the 3 pigs building houses stories? :)

[Bill Gill]

There are ways to build conventional homes that are highly tornado resistant. Here in Oklahoma, in the middle of tornado alley, there are stories on TV every so often about it. It involves extensive structural reinforcement. Of course the price is higher, but if you get hit by a tornado it is well worth it.

As far as moving expensive equipment to the basement. Very few homes around here have basements. And then there is the problem of time. If you have 15 minutes warning that a tornado is coming you are lucky. That gives you time to hunker down in your safe room, if you have one. And sometimes there is essentially no warning, a tornado may unexpectedly develop right where you are.

Personally I want to build a concrete home. Then the whole house is a safe room.

Bill

[Mr. Man-wai Chang]

But both the Americans and Japanese are insisting in using wood.

Are they stealing wood worldwide? :)

[Cindy Hamilton]

Wood is inexpensive; masonry is costly.

Besides, it's always a gamble whether a tornado is going to hit your house and leave your neighbor's standing, or vice versa.

No need to steal it when we can buy it at a reasonable price. Quite a bit of our lumber comes from Canada.

Cindy Hamilton

[clare]

Concrete is a bargain if it stays standing and wood collapses. ICF construction is becoming very common and affordable - and the wood you are getting from Canada you are pretty much "stealing".

As for the gamble - LIFE is a gamble - and the chance of winning the Tornado lottery in places like Kansas and Oklahoma long term are pretty poor. Kinda like the hurricane lotto in Florida and Louisiana - or the wildfire loto in the canyon country of souther California.

Build it as if you KNOW you are going to get hit.

[Tekkie®]

[e-mail] posted for all of us...

And the good gov't lobby in the USA.

[bob haller]

Steel reinforced conrete homesare good to around 300 MPH winds, resist fires, and could probably be made at least partially flood resistant...

given the severity of weather building codes need to be updated

[Bill Gill]

If you build on a hill instead of on a flat plain they are inherently flood resistant. But it costs more to lay out a development on hills. And you have to make sure the hill won't slide out from under you.

Bill

[Ed Pawlowski]

Use ICFs (Insulated Concrete Forms) and you get the concrete, steel, and the insulation. Quiet too.

[songbird]

our house is mostly made of wood, but has a strong central core (stone/masonry). also it is a hexagon shape.

had a small tornado go through the neighborhood a few summers ago. neighbors lost garages and some roofing, trees down, etc. our place did not have any damage at all. most the time the house will shake a little bit once the winds get above 60mph but that day it didn't shake much at all so i wasn't particularly worried. only to look out after the worst was past did i see the neighbor's garage missing.

a more direct hit likely would have had some damage.

songbird

[Moe DeLoughan]

Wood is less expensive. Safe rooms can be built for just a few thousand dollars, and most people aren't able or willing to spend even that.

I visited a friend in Illinois who took me to a new subdivision that featured a few tornado-hardened homes made out of concrete. They were massive, but still conventionally designed (square/rectangular). I've read a lot of articles on how concrete dome structures are the most resistant to high winds/tornadoes. Problem is, we're not accustomed to the dome home aesthetic, so it's hard getting approval by local governments and mortgage lenders. They're afraid neighbors will complain and the property won't have much resale value compared to neighboring properties.

Basements aren't always safe havens. People and property have been sucked out of basements after the tornado took the house off its foundation. And there's an average of fifteen minutes warning of a tornado, and the warning area is generally county-wide. That means most of the warned area will not actually be hit by the tornado, which is why people generally don't take tornado warnings seriously unless/until they see one coming.

It's a matter of balancing risk vs cost. And every time a local authority considers changing the local codes to require structures to have improved wind resistance, the developers complain about the added cost. It will probably take the insurance industry to force widescale change - if their costs due to wind damage become too excessive, they'll raise policy costs to the point where homeowners will have an economic incentive to choose wind-hardened homes, or to pay for retrofitting their existing homes.