Underground Storm Shelters Henryetta
On May 3, 1999 an EF5 tornado struck Moore, OK that had record wind speeds of over 300mph. After that 1999 tornado, we realized that not everyone in Oklahoma had the space to put in a septic tank protector. People had very, very limited choices related to protecting their families from tornadoes. At that time, underground storm shelters in Henryetta were not installed in half the houses they are now.
Immediately thereafter, the first generation of this in-garage, underground storm shelters was born. This allowed for the masses to install a shelter underground, inside their house for tornado protection. Homes throughout Henryetta were installing these underground storm shelters to protect themselves.
This was a good thought for sheltering people and keeping them out of the weather but it had its downfalls. It stuck up 4 to 5 inches away from the garage floor, had poor ventilation, rusted out fast, and had steep, awkward ladders for entry and exit. Many of these underground storm shelters in Henryetta weren’t installed properly and have actually floated up from the ground due to buoyancy and ground water. We took note, and made history.
In 2003, the FlatSafe Tornado Shelter was invented. We engineered our underground storm shelters, to be installed in-garage to deal with the destructive forces connected with tornadoes that would offer our Henryetta customers peace of mind and provide them with the maximum probability of survival in an EF5 tornado.
Through extensive research, we identified vacuum, air pressure, and debris as the most damaging forces connected with tornadoes.
- Vacuum
With possible wind speeds of 300+mph in mind, we realized that vacuum is among the most damaging forces that tornadoes create. It does not require much vacuum pressure, with respect to psi, to cause structural damage. To counter vacuum forces, FlatSafe designed a lid system that allows for 360o of ventilation for rapid equalization of pressure within the shelter. By boosting the pressure inside of the shield to quickly equalize with the outside pressure, the secured lid system is held securely closed.
- Pressure
We recognized that 300+mph winds can cause enormous damage to whatever it slams against so we sought to lower our exposed surface area as far as possible. The patented FlatSafe lid system only sticks up 1/4″, therefore there’s very little surface area affected by horizontal wind speeds.
- Debris
Because FlatSafe Tornado Shelters are below ground, it is from the way of horizontal winds and the debris thrown and circulated by it. So the only debris to worry about is falling debris. We understood that all debris falls at exactly the exact same speed and just mass determines its effect. Our 1/4″ plate lid is bigger than the shield opening and is reinforced to absorb and withstand any falling debris which may land squarely on it. We designed it to provide more than sufficient ventilation (breathing) even after impact.
FlatSafe Underground Storm Shelters
The FlatSafe Tornado Shelter was engineered to meet all of the regulations and criteria that were available. It was also engineered with corrosion protection options to make sure that the shelter would last as long as the house and the homeowner. FlatSafe supplied the first single-lid design and was the first low-profile, in-garage shelter given. The lid is 1/4″ thick steel plate with added structural tubing to give additional strength. The single-piece lid is larger than the framework of the saferoom opening and sits over the frame, not down inside the frame.
Our lid system is a lot stronger than the normal 2-piece lid system provided by everyone else and provides more than adequate ventilation to the occupants. FlatSafe was the first to encase lands in ready-mix concrete to counteract buoyancy and floatation. The FlatSafe shelter design does not remove from a homeowner’s usable garage floor space.
FlatSafe below ground storm shelters permit easy entry and exit, provides a powerful system for exiting with debris onto the lid, and leaves Henryetta residence with the peace of mind that they have a very large probability of surviving a direct hit from an EF5 tornado.
Read Real Testimonials From Tornado Survivors
Since 2003, FlatSafe has established itself as the innovator in the in-garage, low profile, below ground storm shelters industry. Many FlatSafe shelters have taken a direct hit from an EF5 tornado and our customers rave about the shelter performance and their choice to purchase. FlatSafe continues to push for new innovation and continues to push for more stringent and comprehensive codes to protect the families in and around Henryetta.