Each civil defense fallout shelter constructed in the city shall be subject to the following minimum standards and regulations.
(a) Any use of fallout shelters other than for disaster protection shall be incidental to disaster protection, and shall not be allowed to interfere with the primary protective function of the shelter.
(b) Civil defense fallout shelter sanitary facilities shall not be connected directly to the city sanitary sewer system or to any septic tank sewer system. Each civil defense fallout shelter shall have a chemical toilet facility or an adequate supply of plastic bags or closed containers adequate to serve the number of persons to be housed in the civil defense fallout shelter during a disaster situation.
(c) Storage of fresh water within the civil defense fallout shelter shall be provided on a basis of one-half gallon per person per day.
(d) Civil defense fallout shelters having a manually or mechanically operated ventilation system shall provide a flow of three cubic feet of fresh filtered air per minute for each person occupying the civil defense fallout shelter. Civil defense fallout shelters without forced ventilation systems (either manually or mechanically operated) shall provide 500 cubic feet of space per occupant. Any civil defense fallout shelter using a mechanical ventilating system shall have an auxiliary power source, and such auxiliary power source shall meet all requirements of the fire and electrical codes of the city. Each civil defense fallout shelter shall have a filtering system for its ventilating equipment. Reasonable protection shall be provided aboveground for the air filter vent so as to reduce the possibility of damage to the air filter vent. The air filter vent shall extend at least 36 inches above the ground.
(e) Civil defense fallout shelters shall conform to the requirements of the zoning ordinance of the city and such shelters shall be so located on a lot as to meet the minimum yard requirements of the zoning ordinance for the district in which a civil defense fallout shelter is located. For the purposes of this article, a civil defense fallout shelter not attached to the residence shall be treated as an accessory building.
(f) Civil defense fallout shelters shall be posted with an appropriate sign showing the capacity thereof as determined by the civil defense shelter board.
(g) Civil defense fallout shelters shall be maintained in a safe and sanitary manner and shall not be used for the storage of material other than those considered desirable equipment or provisions for use as a civil defense fallout shelter.
(h) Civil defense fallout shelters shall have a minimum amount of floor space as follows:
Rated capacity in persons | Sq. Ft. living area per person (based on stacked bunks) | Sq. ft. storage space per person | Minimum sq. ft. required |
1 | 24 | 2 | 26 |
2 | 12 | 2 | 28 |
3 | 10 | 2 | 36 |
4 (or more) | 10 | 2 | - |
(i) Single-family civil defense fallout shelters shall have at least one means of access and egress which may be entered from within the main dwelling if constructed as an addition to the main dwelling or from the outside of the shelter if treated as an accessory structure. Stairs and exits for civil defense fallout shelters shall meet all exit requirements of municipal and state fire codes. Placement of the stairway shaft or entranceway for single-family or community civil defense fallout shelters shall provide at least one 90 degree turn in the stairway shaft or entranceway before an entrance is made into the main shelter.
(j) The walls and floor slabs of all aboveground civil defense fallout shelters shall be waterproofed, and the roof, walls and floors and slabs of all underground shelters shall be waterproofed, using either a plastic membrane, mopped on asphaltum or integral mixed water-proofing.
(k) Civil defense fallout shelters and all parts thereof shall be of sufficient strength to support the estimated or actual dead and live loads to which subjected, in addition to their own proper dead load, without exceeding the maximum stresses allowed for various materials by the applicable provisions of the building code of the city; provided that, no part thereof shall be designed for live loads less than the following:
(1) For an aboveground shelter with a roof elevation including shielding material of more than six feet above the highest elevation of the adjacent yard, the roof shall be designed for a minimum live load of 25 pounds per square foot;
(2) For aboveground shelters with a roof elevation including shielding materials of less than six feet above the highest elevation of the adjacent yard, the roof shall be designed for a minimum live load of 100 pounds per square foot; provided, that special provisions shall be made for possible concentrated loads, such as those which would be imposed by loaded trucks;
(3) The walls of shelters constructed partially or wholly below the adjacent ground grade shall be designed to resist the lateral pressure of the retained adjacent earth in accordance with good engineering practice. Where the walls retain only well-drained earth, they may be designed for pressure equivalent to that exerted by fluid weighing not less than 50 pounds per cubic foot and having a depth of that of the retained material, including surcharge;
(4) Floors of civil defense fallout shelters shall be designed to withstand the hydrostatic pressure to which they may be subjected, without exceeding allowable maximum stresses as specified for various materials in the building code of the city;
(5) Civil defense fallout shelters shall be designed to withstand displacement which might be caused by buoyancy produced by the surrounding fluid materials; and
(6) Family civil defense fallout shelters or group civil defense fallout shelters may be constructed of masonry, reinforced concrete, steel, plastic or other approved materials. The following table shows in inches materials sufficient to give a radiation reduction factor of one to 1,000 if constructed below ground level:
Concrete (inches) | Earth (inches) |
Concrete (inches) | Earth (inches) | |
18 | plus | 0 |
15 | plus | 5 |
12 | plus | 9 |
10 | plus | 12 |
8 | plus | 15 |
6 | plus | 18 |
4 | plus | 21 |
0 | plus | 27 |
(1964 Code, § 10-6)