Building Science

2015 Codes for Storm Prone Areas Make a Case for Insulated Concrete Block

Tornado season is almost upon us. Vast parts of Texas, Oklahoma, Kansas and Missouri are preparing for another spring of potentially severe weather, volatile storm systems and tornadoes that threaten property and personal safety. According to American Meteorological Society, the U.S. sees about 1,000 tornadoes a year on average, many occurring in the spring in “Tornado Alley,” spanning a large region starting in north and west Texas to the Upper Midwest.

Many tornado-prone states and municipalities are adopting more stringent life-safety building codes and standards that are challenging architects and contractors to design stronger and safer structures. In many cases, these codes require interior safe rooms or stand alone buildings that are designed to provide what the Federal Emergency Management Agency (FEMA) has termed as “near absolute protection” to building occupants in areas where windstorms are more common.

The urgency of building according to these new standards has increased in recent years with the devastation of communities across the Midwest and Southeast because of tornadoes, along with the severe and costly destruction of cities and towns across the U.S. Gulf Coast from large storms like Hurricane Katrina.

However, these new life-safety requirements can create financial challenges, especially for schools and other high occupancy buildings that may now be required to provide FEMA rated safe rooms for all building occupants. According to FEMA, one cost-effective way to provide protection for large numbers of people is by constructing new stand-alone buildings specifically designed and constructed to serve as a tornado or hurricane safe room. Insulated concrete block is an ideal material that meets these requirements.

According to the FEMA 361 publication “Design and Construction Guidance for Community Safe Rooms,” the advantages of a stand-alone safe room include:
● locating the new building away from potential debris hazards
● keeping the safe room structurally separate from other more vulnerable buildings
● eliminating the need to integrate the safe room into an existing building design which can be complicated and expensive
● designing a safe room that is sized according to needs rather than by available space in an existing building

Wall systems that use concrete are proven to offer a great combination of performance and cost effectiveness for constructing safer buildings and stand-alone safe rooms that can withstand the powerful winds and destructive flying debris associated with tornadoes and hurricanes. Recent tests performed at the Texas Tech Wind Science and Engineering (WiSE) labs have confirmed that insulated concrete blocks with a masonry finish provides a stronger, more cost effective option for providing wind debris protection while also delivering superior energy efficiency, fire safety, and noise reduction.