Tom helped a local contractor build a tornado safe room for a new construction project. The home owner wanted a concrete and steel “basement” located underneath his garage floor. The garage is a 40 X 50 foot structure. The homeowner poured part of a basement in the garage on one end. The idea was to have a concrete slab floor poured over the top of the hole to form a safe room. The steel and concrete floor will enable the homeowner to still utilize the entire garage floor for parking and storing vehicles. The safe room below can be used to store valuable items as well as serve as a place to go in the event of a tornado or other emergency.
As the foundation walls were formed, beam pockets with weld plates were added so that the steel beams would sit flush with the foundation and the bottom of the concrete slab. Steel beams were placed in the beam pockets across the opening of the newly formed basement. The opening was then covered with metal floor pan. The floor pan supports the concrete floor as well as add additional support to the garage floor. Floor pan is generally made out of galvanized steel. The tornado room ceiling will then be tied into the entire garage floor while the concrete flat work is completed. This allows the whole concrete floor the expand and contract over time.
The picture shows one heavier beam that sits perpendicular to the rest of the steel beams. This allows for an opening for a stairway down to the tornado room.
The smaller steel beams are W6 X 9 lbs per foot. The heavier beam is a W6 X 25 lbs per foot. There is a steel post near the end of the heavier beam. As building continues, additional re bar and concrete will be added.
The tornado safe room will be tied into the remaining structure and will be made entirely of concrete and steel. The picture at the bottom of the page is a view with galvanized floor pan covering the basement prior to concrete.
If you are interested in building a tornado safe room in your new construction, it is important to remember that it should be professionally engineered.