Tornado: Building Codes and Safe Rooms
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.
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.