Tornado: Building Codes and Safe Rooms
By ccarlstead
Withstanding the brutal ripping force of EF5 tornado is unfeasible, but not impossible. Tornadoes ripping throughout the central part and Mid East part of the United States are not one time events, but they aren't likely to repeat at the same location for at least 5,000 years, following statistical models. While the nation looks to establish greener construction methods and earthquake-resistant buildings, Tornadoes forces are being overlooked, and it is possible that a building code considering tornadoes ripping forces would never become a reality.
The lapse of time between two tornadoes striking in any given location is five times the probability of that same area being hit by a hurricane, because tornadoes are narrow enough to impact a small area contrary to hurricanes that can sweep away states and large areas. FEMA recommends to establish Safe Rooms to help protect lives and property, withstanding 200 mph winds and resisting a two-by-four wood piece hitting the wall at 100 mph. Newer codes like ICC-500 and the FEMA 361, have redefined the safe rooms' standards for tornadoes and hurricanes.
By Mllerustad
Construction experts have been studying this phenomenon for years and they can establish that sometimes tornadoes damages are greater due to poor construction practices, such as trusses being toe-nailed to the walls, and the lack of anchor bolts between the bottom plate and the foundation. At the same time, they have also found that large tornadoes just like the one in Joplin, Missouri can devastate buildings and structures even with excellent construction designs.
Follow these design guides when building a tornado safe room.
Comments
We definitely need to be more prepared for natural disasters. Having lived in the midwest for most of my life and now living in California, I am very aware of preparedness. One very simple thing that we can all get is a disaster or earthquake kit. It’s inexpensive, has food, water and emergency supplies to use until help arrives. Keep it in the safe room and you’re ready for anything. Be prepared!
I also have had the chance to deal with some of the worst weather you can imagine. I have never had to deal with a tornado, but i have a hurricane. I now live in Utah and we worry about earthquakes here more than severe weather. I believe the best way to control the outcome is to be prepared. Even though you really can’t be prepared for everything you should try to be prepared at least for your family for the short term. Even the long term if you can.
BP
Dumpster Rental Pros
I have lived in hurricane zones most of my life. We have learned to be prepared with all the needs you may have after the hurricane strikes. But that doesn’t do anything for the home. Hurricane design has been built into codes in most southern states and does help. But when a roof wants to come off a home, even a 140-mph rated hurricane clip isn’t going to keep it on. Mother Nature is a powerful mama. I don’t believe there is a feasible way to prepare cost effectively for an EF-5 tornado. That’s why we have insurance. The more you prepare the higher the home cost. Earthquakes show that, part of why homes in California are so expensive. As with any kind of disaster-preparedness construction, you have to weigh cost with benefit.
Juan,
Be careful with words. The first sentence notes that, “Withstanding the brutal ripping force of EF5 tornado is unfeasible, but not impossible.” Unfeasible, meaning it is uneconomic. Later in the same paragraph,tornado “forces are being overlooked.” So are tornado resistant structures not in the code because they are unfeasible or because the code writers (and public safety officials in general) are overlooking them? I think the former.
HTH,
Jim
It is better to build concrete or Steel Structures in places likely to be witnessing a tornado. Since they are heavier and tied from top to bottom using better fasteners they will resist Tornadoes better than wooden structures
Tornado terrible disaster …. what a pity that so many people each year suffer from it …
Anyone interested in this topic should review the major article and photos in today’s Kansas City Star regarding the failures buildings using tip-up construction in Joplin, MO. The photos, especially of the big box store collapse, are startling and illuminating. Here’s a link:
http://www.kansascity.com/2011/06/25/2975177/experts-challenge-building-design.html
Why did the playground sets that were built out of plastic and bolted to steel pipe stay in place in Joplin when everything else including old oak trees and 50 year old buildings fell around them? There has to be a lesson in construction to learn here.