HOW TO BUILD A TORNADO SAFE ROOM

When hurricanes and tornadoes strike, it is rarely flooding which does the most damage, but almost always wind. The impact of intense winds on homes, schools, businesses, and communities across the United States is significant in all 50 states – and getting worse. That’s why FEMA has done considerable research on how to construct a safe room so people who aren’t able to evacuate can safely wait it out ‘til the storm passes.

Tornadoes are among the most violent windstorms, with wind speeds far faster and fierce than modern building codes account for. The Enhanced Fujita Scale measures wind based on damage levels. The EF Scale ranges from EF0 to EF5 with wind speeds exceeding 200 mph.

Tornadoes are often concentrated into narrow paths, but the devastation can be catastrophic because most buildings are not designed to withstand such forces. Tornado-resistant construction typically involves reinforced structures, such as safe rooms, to protect people in the most severe storms who somehow did not manage to evacuate in time.

In 100+mph winds, buildings that are not designed to be climate resilient experience significant damage; roofs and walls collapse and windows shatter. When winds enter a building through broken windows or doors, it creates a pressure differential that can lift off roofs or increase the likelihood the whole house will collapse.

Remember Dorothy in the Wizard of Oz? None of us want to wake up to find everyone and everything we know gone. Safe rooms offer protection. Safe rooms are constructed with reinforced walls, roofs, and doors to withstand wind and prevent airborne objects from crashing through. In tornado-prone areas, safe rooms should be located in the center of the building or underground, like in a storm cellar, for maximum safety. However, in hurricane-prone areas, especially those likely to flood, the opposite is true. Safe rooms should be elevated – far above sea level – and located outside storm surge to protect you from flooding.

FEMA – which is short for The Federal Emergency Management Agency – oversees emergency operations during climate disasters and has put out guidelines for constructing safe rooms.

1. The first key is to use materials and designs that can withstand extreme wind: reinforced concrete for walls and foundation; steel framing, shutters, reinforced doors or window frames; impact-resistant glass windows; pressure-treated wood; metal roofing; fiber cement siding; storm shutters; hurricane straps and clips; and spray foam insulation in walls and roofs. By combining these materials, you can significantly increase your home’s ability to withstand extreme winds.
2. Next, before you start building, make sure your safe room is elevated above expected flood levels from rain or sea level surge.
3. There should be no windows in your safe room – and if there are, make them impact-resistant.
4. Emergency relief groups emphasize the importance of proper sheltering practices and adhering to local building codes so be sure to check out their guide below.

In addition to safe rooms in homes, FEMA recommends towns build them in schools, gyms, libraries and other community spaces so everyone can get to safety during a storm. Safe rooms should be accessible to all residents, with an eye towards people with disabilities, and making sure people will be comfortable during extended shelter-in-place periods.

LINK TO FEMA PDF