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Tornados and Wind Zones

jar546

jar546

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In lieu of the recent events in OK and other states that have had significant damage from twisters, does it seem practical to evaluate and possibly change the wind zone in those areas of the country. I look at how buildings are constructed in Florida along the coast and can't help but think that the CMU construction, windows/shutters and roof system would be beneficial to the residents of those areas. (my thoughts are commercial and residential)

Some of the issues I see with this thinking are:

1) We are talking about a very large area of the country

2) The rush to rebuild after an event would outpace the ability to change, learn, enforce.

3) There would be a lot of resistance from the building community.

You can say that more money should be put into early warning devices but if there is not enough time to get a large quantity of people moved to a safe location, what is the use? I would rather be in a safe area of a well constructed CMU house than in a stick framed one.

Let the debate begin.
 
I think it would be more beneficial from a cost standpoint not to require an entire structure to be built to higher wind resistance but to require a safe room along these lines Safe Rooms | FEMA.gov

of course this will increase costs for new construction, would not be retroactive for existing structures so ......... besides we can't even get sprinklers in residences, talk about one heck of a fight requiring all new structures to be constructed to survive a 200 mph wind load just my humble thoughts
 
"Most tornadoes have wind speeds less than 110 miles per hour (177 km/h), are about 250 feet (76 m) across, and travel a few miles (several kilometers) before dissipating. The most extreme tornadoes can attain wind speeds of more than 300 miles per hour (483 km/h), stretch more than two miles (3.2 km) across, and stay on the ground for dozens of miles (more than 100 km)." Hurricanes can be a couple of hundred miles across and the wind speed dissipates rather quickly when it travels across land. It makes sense to have a code where a natural disaster such as a hurricane, seismic event, areas of flooding or heavy snow may affect a large region but a tornado unless it hits a populated or overly developed area leaves minimal damage in terms of dollars or loss of life.

The United States averaged 1,274 tornadoes per year in the last decade. April 2011 saw the most tornadoes ever recorded for any month in the US National Weather Service's history, 875; the previous record was 542 in one month.[2] It has more tornadoes yearly than any other country and reports more violent (F4 and F5) tornadoes than anywhere else. The state which has the highest number of tornadoes per unit area is Florida, although most of the tornadoes in Florida are weak tornadoes of F0 or F1 intensity. A number of Florida's tornadoes occur along the edge of hurricanes that strike the state. The state with the highest number of strong tornadoes per unit area is Oklahoma. The neighboring state of Kansas is another particularly notorious tornado state. It records the most F4 and F5 tornadoes in the country
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wikipedia
 
The fire fighting community has been advocating and fighting for residential sprinklers,

or for heavy timber type construction to be used, for a long, long time, and that effort

hasn't come to fruition yet, ..even with their continued number of fire fighters being

killed in Residential fires.

How many will have to die before a significant change in the framing codes; in the

higher wind areas/zones, will actually come in to existence. Essentially, the builders

lobbying efforts for cheaper and cheaper construction materials currently is greater

than those that oppose them.

.
 
maybe require a safe room at a cheaper cost??

not sure you are going to stop a tornado or hurricane
 
A Government Agency / Municipal may (should) require planning and installation of safe structures; safe rooms / shelters when planning public construction. my heart breaks at the recent news of the Oklahoma elementary schools today. Areas such as Libraries, cafeterials, gymnasiums, assembly halls, and perhaps even corridors can be designed and rienforced either by concrete dome / partial subgrade even within conventional construction that would be sacrificed around such an internal bunker. those spaces are large enough to shelter normal and short term increased occupancy. The next new public facilty must include these types of facilities. It does not take a law or a suggestion from a building official to enact common sense.
 
I think this is about reducing risk and protecting people whether in their own home or out and about in public places.

If there are 200 people shopping in a Walmart, is there a room big enough to fit all of them?

I would think (unscientific opinion) that having buildings in areas prone to tornados (of different categories) built to a higher standard just like those on the coast would increase the likelihood of survivability. All wood structures just don't cut it.
 
Architect1281 said:
A Government Agency / Municipal may (should) require planning and installation of safe structures; safe rooms / shelters when planning public construction. my heart breaks at the recent news of the Oklahoma elementary schools today. Areas such as Libraries, cafeterials, gymnasiums, assembly halls, and perhaps even corridors can be designed and rienforced either by concrete dome / partial subgrade even within conventional construction that would be sacrificed around such an internal bunker. those spaces are large enough to shelter normal and short term increased occupancy. The next new public facilty must include these types of facilities. It does not take a law or a suggestion from a building official to enact common sense.
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The problem with common sense is that not everyone or every entity has it or even understands it.
 
In spec. homes, who will be paying for the increased Wind Zone construction requirements?

Kinda the same question as Residential Sprinklers!

If building contractors are required to actually increase their construction practices to a

higher wind category (i.e. - meaning "more out-of-their-pocket" costs), ...where will their

profit margins come from, or how will they continue to make their levels of profit?

.
 
if you don't make profit you go out of business ..... been seeing a lot of that lately

as with the hurricane prone area construction it gets past on to the consumer
 
I would like to build a house on the water in Miami but I can't afford to. I would like to build a house in Aspen, Colorado but I can't afford to. I would like to buy and renovate an apartment in Manhattan but I can't afford to. I would like to build a 5 bedroom house with a heated pool but I can't afford to. I would like to be on vacation 50 weeks a year but I can't afford to. I am finally building a house somewhere that I can afford to and its in a 120mph wind zone about 8 miles from the water. In other words, I am doing what I can based on the cost for the area I am living in.

If you want to build a house but can't afford to build one that meets minimum standards then you can't afford to build a house. Why should the bar be lowered? Is this not what got us into the most recent recession with all of the bankers lowering the bar?

Why should I care about a contractor's profit margin? There were several times when things were going gangbusters and many contractors were living the high life and not investing or saving their money but spending it. The market always takes care of itself with supply and demand. If you keep lowering the bar to bring more people to the table you are part of the problem. I soon turning 48 and can finally afford to build a house vs buying an existing one.
 
I miss the good old days when there was a nuclear bomb shelter on every corner, stocked with canned water and soda crackers
 
It does make sense the wind maps on the ICC shows a wind speed of 90

That is BS in an area prone to these tornadoes.

Yes changes need to be made. We all are paying, through FEMA funds and insurance for this stupidity
 
The easy thing to do is to address the problem of mobile homes. They are a disaster waiting to happen. As a minimum we should find a way of tying them done for wind similar to what is done for earthquakes in parts of the country.

Then we should separate out the damage due to a tornado passing over a building and damage to nearby buildings.

Designing a building to resist a direct strike from a major tornado is possible but maybe difficult. On the other hand I will suggest requirements similar to those used in hurricane areas would greatly improve performance. But unless you are willing to address the enforcement issue don't bother.
 
Mark K said:
... mobile homes. They are a disaster waiting to happen. .
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51TnC3DEG5L._SL500_AA280_.jpg
 
From what Uncle Bob has posted from his experience in that area I believe a major education for builders and inspectors would go a long way in reducing the damage to buildings in that area from a wind borne event. I agree increasing the wind loading requirements along with protection from wind borne debris for windows and doors would go a long way. I remember him posting they do not even use J-Bolts in that area to secure the house to the foundation. New and stricter codes will do nothing if there is no enforcement. Does anybody remember the Grand Jury Report after Hurricane Andrew and their findings?
 
This website has some very interesting information tornados, including wind speeds, numbers of tornadoes, and deaths.

The Fujita Scale

Storm Shelters

It might not be much more difficult to design a structure to witstand a moderate ot significant tornado (F1 or F2), but even a concrete bunker would be damaged in the worst ones (F4 & F5). In hurricane zones you're talking about designing to resist penetration by a 2x4 shot out of a cannon, not a flying car or tree. Safe rooms or underground shelters would be a more cost-effective way to save lives in tornados than requiring an entire house to resist a severe (F3) or worse tornado.
 
Part of the problem is the building code is no retroactive. In many parts of the country the requirements for mobile homes are more stringent but you still have the ones that have been around for 20-30-40 years. As for the building codes, I agree in part. My thoughts would be the requirement of a safe room in new construction and additions, have read that some of the safe rooms can be constructed for around $5k. For commercial structures the wind importance factor should be increased from 1.00 for most structures to 1.15 or 1.25.

Again, just my thoughts
 
There is no retroactive when the city was flattened in 1999 and they chose not to require shelters

They chose not to require shelters in their new federally funded schools

They chose not to require shelters in the federally funded medical center

They saved a few dollars. How much is a life worth
 
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