Windstorm Solutions for Hurricanes and Tornadoes
Various codes apply when preparing for the forces of nature
- By Minu Youngkin
- Sep 01, 2014
Adverts Every year, the country braces for Mother Nature and the
havoc she unleashes with major windstorms. At one time, only
coastal states like Florida seemed to be affected. In recent years,
however, the destruction has veered beyond Florida, requiring
many states to seek shelter from the storm. Consider this:
- From 2010-2012, there were more than 3,900 tornadoes, resulting in 667 deaths
in the United States.
- Between 2010 and 2011, 31 hurricanes or tropical storms caused more than 387
deaths and more than $33 billion in damages.
- Nearly every state is at risk for tornadoes or hurricanes.
It All Starts with Code
When it comes to windstorm solutions, it’s all code-driven as door, lock and hardware
chosen for an opening are determined by hurricane or tornado codes. The
challenge comes with knowing which codes apply.
“Windstorm solutions can be tricky because codes can vary by state, and even
county,” said Lori Greene, manager of codes and resources at Allegion. “With
hurricanes, for example, the old Southern Building Code (SBC) was the first code
to include hurricane-resistance requirements in building construction design, and
Miami-Dade County was the first state entity to enforce compliance of this code.
However, these requirements and testing protocols to address the state of Florida have since been incorporated into the
Florida Building Code.”
Additional requirements may apply
to certain types of buildings for enhanced
“Schools and hospitals, for example,
may have additional hurricane
code requirements in certain regions,”
said Steven King, a specification writer
While most buildings in coastal
states are subject to windstorm codes
for hurricane protection, it’s a different
story in tornado regions, namely the
center of the United States.
“The current national codes are
not specific about which facilities
are required to have storm shelters,”
Changes have been approved for
the 2015 edition of the International
Building Code that will require storm
shelters in educational occupancies
and emergency operations facilities
in certain parts of the country. Green
said that these new requirements will
be adopted on a state-by-state basis, so
it’s important to check with your state to know what is required. However, regardless
of whether your state adopts
them, Green advocates compliance
with the new requirements because they
reflect best practices nationwide.
The main codes and standards
that apply to windstorm solutions are
shown in Table 1.
Types of Buildings
In hurricane regions, many types of
buildings are required to have windstorm
solutions, including—but not
limited to—schools, healthcare facilities,
commercial buildings, retail locations
and community storm shelters.
In tornado regions, typically schools
and community shelters are subject to
windstorm shelter requirements. Shelters,
however, may be built in a variety
According to Casey Cohorst, CSI,
CDT, LEED GA, a specification consultant
with Allegion, the type of application
may also drive the final solution.
“Like any other door solution, windstorm
solutions have unique requirements
based on the application,” Cohorst
said. “What is done for an exterior
door may be different than a door for a
classroom wing or gymnasium used as
a shelter. What you need may vary by
building, or even door by door.”
Integrating Access Control
Openings equipped with windstorm
solutions can still have access control.
However, because of the unique windstorm
assembly, there are special considerations.
“We can definitely provide access
control for a hurricane or tornado door,
and there are a couple ways to do that,”
King said. “Because an electric strike
can’t be used on these openings, we generally
recommend an electronic lock.”
Electrifying a Von Duprin panic
device is another way to add access
control to an opening.
Proven to Perform
The last consideration for choosing
a windstorm solution is performance
testing. Allegion simulates wind
speed and potential projectile impact
to measure how its products hold
up—individually and as an assembly,
which includes doors, frames, locks
For hurricanes, Allegion products
are tested to resist windborne debris
impact loads and cyclic, static wind
pressures as prescribed by the Florida
Building Code. With tornadoes, these
products are tested to the most stringent
FEMA 361/FEMA 320/ICC 500
requirements, withstanding 250 mph
sustained winds and 15-lb projectile
impacts at 100 mph.
This article originally appeared in the September 2014 issue of Security Today.