|
Building a Tornado Safe Room in
your home.
Every family needs to have a designated space in their home to use as a
shelter from a tornado.
Caveat emptor - The following is just an opinion built on
personal experience and expert training. Use at your own discretion.
I live in north Texas, just north of the Dallas and Fort
Worth Metroplex. Every couple of years or so we have a storm large enough to
produce tornadoes, and they do. We have seen what the weather service call EF1, EF2 or maybe as large as a
EF3 tornado. So far the big EF5, which they say we're over due for, hasn't
happened (thankfully!). Tornadoes are rated by the National Weather Service on the
Enhanced Fujita
scale. An
EF3 is strong enough to do serious damage to your home but leave
interior walls standing. So it make sense to take shelter in an interior part of
your home during a tornado warning. A room like a walk-in closet that IS NOT on an
exterior wall. If you live in a home that has a crawl space or basement, then
getting below the floor is the best place to take cover. But here in Texas and
Oklahoma, most all new homes are built on concrete slabs.
But what can you do to build a shelter in your home to protect yourself from the
damaging winds of a tornado? You can build an interior room with additional
strength to give it the ability to remain standing if your home is in the path
of a tornado. It all depends on how much you are willing to spend to reinforce
this room. My clients take this matter seriously and so do I. Although I realize
that here in Texas we have more State Lottery winners than we have tornado
victims. Meaning, you have a better chance of winning the Lottery than being a
victim of a tornado. However, more and more of our clients are asking what can
they do to protect themselves from a tornado.
Home Built Safe Rooms - In my opinion, the first step is to anchor the walls of your
designated safe room securely
to the foundation. Many builders like to use power driven anchors around
the perimeter wall. That's where they have a device that has a 22 cal. cartridge
in it and an anchor is shot into the concrete slab. This gives OK reinforcement
to any horizontal movement but none to any vertical movement. This type of
anchor is not acceptable for a storm safe room.
Simpson
Strong Tie have anchors designed to give the proper tie down for the wall
where your safe room will be. The next step is to secure the walls and ceiling
joist to the bottom plate. Simpson also has excellent devices to use to
accomplish this. After that, two layers of 3/4" of plywood or OSB around
the inside of the room. Some believe a 14 gauge continuous steel behind the two
layers of 3/4" plywood is needed. Something new that some builders are
using is
DuPont Kevlar. That's the same material
bullet proof vest are made of. Finish it off with a solid core door that has a 2" dead
bolt to secure it shut. A room built such as this should very well with stand an
EF3 to EF4 tornado. However, the winds of a EF4 or EF5 could lift a vehicle off
the ground and fly it through the air. If this vehicle landed on your safe room
the room might not be as safe as you would want it to be. The only SAFE place to be
during a EF4 or EF5 tornado is in an underground shelter. An
EF5 will leave an
empty slab where your home once stood, including your safe room. It was an EF5
that hit
Greensburg, Kansas
in 2007.
I have recently found a product that I've
sent for more information on. It's call Storm Blocker. Take a look at their
website and watch the videos. The thing I have an issue over,
being the frustrated designer that I am, is having a space in the house that
looks like an ugly bank vault. This just might be a good solution to this.
FEMA has a couple of detail sheets of their Safe Room design.
You can download the PDF sheets
here(1) and
here(2).
Commercial Safe Rooms - This is an industry that has
taken off in the past decade or so. The engineering schools have been shooting
2x4s into walls studying how to build a safe room that can with stand the
forces of the BIG ONE, the EF5. I have seen commercial safe rooms made of steel
and rooms made of concrete. The makers of these rooms claim they can with stand
a 2x4 piece of lumber being shot at it at 200 miles per hour, about the minimum wind
speed of an EF5 tornado. My question is, "If a
Ford F-150 pickup truck is lifted off the
ground and hurled at my safe room at a speed of 200 miles per hour, will my
family survive?" Now for most tornados that occur, this will not happen. The
BIG EF5 tornado
is one out of a hundred and the odds of your home being struck by any tornado
is, well, like I said, you have better odds at winning the State Lottery than
being a tornado victim. But there's always that one time it happens to somebody.
Ask anybody in Greensburg Kansas.
Develop a Plan for you and your Family - Although the odds of any of us being a tornado victim are
small, ever family needs a plan and a designated place in the house to take
shelter if you do find yourselves in the path of any tornado of any size. This
needs to be an interior space of small size on the first floor of your home. If
you live in a house with a crawl space or basement, then find a suitable space
there. During the spring and summer, keep this place cleared from storage and be
ready to take shelter in a moment's notice. Get your family a Weather Alert
Radio that has the S.A.M.E. (Specific Area Message Encoding) feature in it.
Program it for the county or parish you live in. The NWS performs a weekly test
on Wednesday and make sure yours is working. Tornados have been know to occur at
2 in the morning with no warning. This radio will should you that warning. In
the spring and summer months, always keep one eye to the clouds and keep
informed by the
TV weather
dude if there is the possibility of severe storms
forming in your area.
Tornado Safe Rooms
Jerry Karlovich has been designing
homes for over 35 years for builders and home owners in the north Texas and
southern Oklahoma area. In the past ten years our clients come from all over the
United States and the globe with homes being built in Ireland and New Zealand.
Jerry is also an
Amateur Radio
Operator and serves as a
severe Storm Spotter for the National Weather
Service and undergoes severe storm training once a year for the past 30 years. These Severe Storm Conferences are taught by the most knowledgeable
meteorologist in the business where the most advanced information of storm and
tornado safety is shared. A Storm Spotter is not to be confused with a Storm
Chaser as in any Hollywood movie. I just let the storms come to me and I
don't go looking for them.
|