According to the Federal Emergency Management Agency (FEMA), for a structure to be tornado-proof, it must be missile-proof.
This is because the greatest damage comes not from the twister’s winds, but from the debris it throws at— and through—structures at speeds that can surpass 200 miles per hour.
Reinforced concrete masonry has a relatively high mass that helps it resist the large uplift and overturning forces of tornadoes and other high-wind events. Additionally, the grout and steel in these reinforced walls create a strong, cohesive unit. This reduces the number of connectors needed and, consequently, the number of potential weak points.
Safety Should Exceed the Need to Save Your Home, Business, or Possessions
If you or your customers live in a high-risk area for wind, hurricanes or storms, it may be time for a storm shelter.
A safe room or storm shelter for your home or small business can provide protection during extreme winds. Types of extreme wind include hurricanes and tornadoes, both of which have a varying level of risk across the country and within each state. When wind enters a building, it can push on the walls and roof from the inside. This, along with the wind from the outside, can cause a building to fail as buildings typically are not designed to resist forces from both the inside and outside.
Tornado severity is categorized by the Enhanced Fujita Scale (EF Scale) which measures wind speeds in addition to a number of damage indicators. An EF4 (165 to 200 mph) and EF5 (200 mph+) tornado will completely destruct even the most well-constructed buildings and wipe the slab of everything. Hurricanes have sustained winds greater than 74 mph and are categorized by the Simpson Hurricane Wind Scale. Along with wind, hurricanes often bring with them storm surges and abnormal rises in sea level.
FEMA's Taking Shelter from the Storm: Building a Safe Room for Your Home or Small Business describes in detail the types of wind hazards, how to assess risk, and how to plan for a safe room. There are many considerations to make when deciding if you need a storm shelter including what wind zone you are in, what type of design will work for your space, cost, and materials.
The Portland Cement Association (PCA) looked at investigations from previous hurricanes and determined that masonry systems seemed to resist breaching as well, if not better than, other wall systems. During tests, concrete wall systems that were impacted by hurricane-carried debris and tornado-force winds suffered no structural damage.
“Wind is not an issue when you build with masonry due to the stringent load requirements established by the International Building Code for masonry, especially when you do steel-reinforced construction,” says Peter Fortier, Architect, AIA, EDAC of LACHIN Architects, APC in New Orleans.
Additionally, PCA noted that masonry veneer historically performed well when properly constructed and connected to the structure. When damaged, it was often because the ties themselves were corroded or inadequate.
The association states: “Masonry veneer structures subjected to storm surges were, in many cases, able to withstand the storm surge better than wood frame houses without veneer.”
Explore our Echelon Masonry product line to view masonry, veneers, wall systems, mortar mixes, and more that can help against high winds, fire, and other disasters.