NTA has reviewed the structural design of the 12 gauge walls, 12 gauge ceilings and anchorage of Securall Storm shelter for an F5 tornado and have found that the design of these elements is in accordance with accepted design standards. Further we have conducted tests to establish the racking strength of the walls and used this test data as part of the basis for our structural review.

The design loads and wind pressures were taken from ASCE 7-05, "Minimum Design Loads for buildings and other structures" for a 250 MPH wind. These are the loads referenced for an F-5 tornado by the NSSA (National storm safety association) and Texas tech university in their publication "Taking shelter from the Storm", also known as FEMA 320, as well as the fourth draft of the proposed ICC/NSSA "Standard on the design and construction of storm shelters", ICC-500 and the FEMA document "National performance criteria for Tornado Shelters".

Having a safe room in your home or small business can help provide "near-absolute protection" for you and your family or your employees from injury or death caused by the dangerous forces of extreme winds. Near-absolute protection means that, based on our current knowledge of tornadoes and hurricanes, there is a very high probability that the occupants of a Storm shelter built according to this guidance will avoid injury or death. A storm shelter can also relieve some of the anxiety created by the threat of an incoming tornado or hurricane. Our knowledge of tornadoes and hurricanes and their effects is based on substantial meteorological records as well as extensive investigation of damage to buildings from extreme winds. Securall offers safe rooms for use in homes as well as in small businesses.