An outside semi-mounded steel igloo shelter is designed to provide low-cost protection from the effects of radioactive
fallout. Its principal advantages are it provides fall out and limited blast protection and is suitable for either indoor or outdoor installation, and is easily assembled. If you're looking to build a shelter that can help protect your family, does it make sense to learn how to build a fall out shelter made out of steel? Yes, definitely.
Space and Occupancy
The shelter type detailed in this design has about 80 square feet of area including the entrance space. The interior has about 260 cubic feet and will house six persons.
Availability and Cost of Materials
This shelter is of the prefabricated type and is available at department stores, building supply outlets, and mail-order firms. Cost is about $175.
Fallout Protection Factor
The protection factor should be about 500 with the prescribed thickness of covering and proper shielding of the entranceway.
Blast Protection
This shelter could be expected to withstand a limited blast overpressure of 5 pounds per square inch.
Ventilation
Ventilation is provided by a 3-inch intake pipe to which should be attached a hand operated blower. The air is vented through the airspace left in the entranceway.
Construction Time
The igloo steel shell requires 4 man-hours to assemble. Excavating and covering time should take 24 man-hours.
Structural Life Expectancy
The igloo, when coated with mastic, has a life expectancy of at least 10 years.
This guide on how to build a fall out shelter will provide a step by step procedure on how to make one. A list of materials is also included.

