TORNADOES:
Narrowing the Path of Damage
STREETS LINED WITH DEBRIS,
CARS OVERTURNED, TREES
UPROOTED, AND A CITY
LEFT IN RUINS.
This was the scene on May 20, 2013, after
an EF-5 tornado ripped through Moore,
Oklahoma, killing 24 people. Just 11
days later, another devastating EF-5 tornado struck south of Moore in El Reno,
Oklahoma, leaving 20 people dead. The
images of destruction reflect how violent
these storms were and can be. But they
also beg the question – what can be done
to reduce the amount of damage tornadoes cause?
Although a structure is likely to suffer substantial damage or be totally destroyed
by an EF-5, EF-4, or even EF-3 tornado,
there are ways to reduce damage caused
by both lower severity tornadoes and
around the periphery of powerful tornadoes like those that devastated Moore
and El Reno.
“We can narrow the path of tornado damage,” says Julie Rochman, IBHS president
and CEO. “We could effectively eliminate
EF-0 and EF-1 damage if we made homes
less brittle, tied them together properly
and protected all the openings.”
However, before property owners can begin to think about stronger, safer building
choices, it is vital to address life safety issues. While building a storm shelter is one
solution, residents without one should
have an action plan for when tornadoes
threaten.
LIFE SAFETY AND
BUILDING SAFETY
“You need to put as many walls as possible between you and the outside storm,”
advises Dr. Tim Reinhold, IBHS chief engineer and senior vice president for research. “If there is a tornado watch – and
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definitely when warnings are issued –
seek a substantial structure, low to the
ground and without windows or other
openings. Unfortunately, since severe
weather can form quickly, there is often not a lot of time to move to the ideal
location.”
Dr. Ian Giammanco, IBHS research scientist, says that building a storm shelter
should be the first priority for homeowners that face a high tornado risk. But if that
isn’t feasible, there are ways to reduce significant damage to a home. The best approach is to take steps to reduce the risk
to both people and buildings, he said.
“Life safety and building safety are intertwined,” Giammanco says. “Coupled with
a storm shelter, there are ways you can
have a structural system that is effective
for life and building safety.”
CREATE A CONTINUOUS
LOAD PATH
Reinhold says the first step to reducing
a building’s risk during high winds created by a tornado is to create a continuous load path throughout the home. This
includes installing reinforcement straps
that attach the roof to the walls, as well
as installing anchor bolts that connect the
walls to the foundation. Without these
connections that travel from the roof to
the foundation, your house is vulnerable
to wind forces. Find out how vulnerable a
house can be without the right connections in this video of windstorm testing at
the IBHS Res X\