Underground Storm Shelters Harrah
On May 3, 1999 an EF5 tornado struck Moore, OK that’d 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 shelter. People had very, very limited choices related to protecting their families from tornadoes. At that time, underground storm shelters in Harrah were not installed in half the houses they are now.
Immediately thereafter, the first generation of the in-garage, underground storm shelters was born. This allowed for the masses to put in a shelter underground, in their home for tornado protection. Homes throughout Harrah were installing these underground storm shelters to protect themselves.
This was a fantastic idea for sheltering people and keeping them out of the weather but it had its downfalls. It stuck up 4 to 5 inches off the garage floor, had poor ventilation, rusted out quickly, and had steep, awkward ladders for entry and exit. A number of these underground storm shelters in Harrah weren’t installed properly and have really floated up from the ground because of 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 involved with tornadoes that would give our Harrah clients peace of mind and supply them with the highest probability of survival in an EF5 tornado.
Through instense 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 recognized that vacuum is one of the most damaging forces which tornadoes create. It does not take much vacuum pressure, with regard to psi, to cause structural damage. To counter vacuum forces, FlatSafe designed a lid system that allows for 360o of venting for quick equalization of pressure inside the shield. By boosting the pressure inside of the shield to quickly equalize with the outside pressure, the secured lid system is held firmly closed.
- Pressure
We recognized that 300+mph winds can cause tremendous damage to anything 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 is very little surface area affected by horizontal wind speeds.
- Debris
Because FlatSafe Tornado Shelters are below ground, it is out of the way of horizontal winds and the debris thrown and circulated by it. So the only debris to worry about is falling debris. We knew that all debris falls at exactly the exact same speed and only 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 made it to provide more than adequate 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 rust protection options to ensure that the shelter would last as long as the house and the homeowner. FlatSafe supplied the original single-lid design and was the first low-profile, in-garage shelter given. The lid is 1/4″ thick steel plate with additional structural tubing to provide additional strength. The single-piece lid is bigger than the frame of the saferoom opening and sits over the framework, not down inside the frame.
Our lid system is MUCH stronger than the normal 2-piece lid system offered by everybody else and provides more than adequate ventilation to the occupants. FlatSafe was the first to encase shelters in ready-mix concrete to counteract buoyancy and floatation. The FlatSafe shelter design does not take away from a homeowner’s usable garage floor space.
FlatSafe below ground storm shelters allow for easy entry and exit, provides a powerful system for exiting with debris onto the lid, and leaves Harrah residence with the peace of mind that they have a very high 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 business. Many FlatSafe shelters have taken a direct hit from an EF5 tornado and our customers rave about the protector 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 the vicinity of Harrah.