(I) Section 409 Tornado Shelters in Schools
(a) The fire alarm system shall not be used to alert building occupants of a tornado, tornado alert, or tornado warning.
(b) The principal or person in charge of the school shall submit a clear, comprehensive, detailed, and legible drawing to the local fire code official, showing the building floor plan(s) and designated tornado shelter area(s). Each room or area shown on the plan shall be clearly indicated as to its particular use.
(c) The drawing required by paragraph (I)(2)(b)(409.2) of this rule, shall be submitted to the local fire code official for his information. A copy shall be maintained in the office of each school, for examination by the state fire marshal or local fire code official.
(d) Tornado drills shall be conducted at least once a month whenever school is in session during the tornado season. For the purpose of this rule, "tornado season" is the period from the first day of April to the last day of July. A record of such drills shall be maintained in the office of each school for examination by the fire code official.
(e) The occupants of modular classroom facilities shall be moved out of such facilities and to the designated tornado shelter area(s) in the event of a tornado, tornado alert, or tornado warning.
(f) Each local fire code official conducting the annual inspection of each school or institution shall be designated pursuant to division (C) of section 3737.73 of the Revised Code to verify compliance with the tornado safety provisions of this rule.
It is recommended that the designation of areas to be used as tornado shelters be in accordance with the following criteria:
Every building is different and contains some vulnerable elements that cannot be counted upon to withstand a tornado. Portions of buildings that contain one or more of these elements should be avoided wherever possible.
(a) Windows, skylights, and other components of glass, should be avoided. Glass is no match for tornado force winds and usually breaks into many jagged pieces which are blown into interior spaces from the windward side. Acrylic or poly carbonate plastics are more resistant to impact than glass, but large panes will pop out. Tempered glass will shatter into thousands of cube-like pieces that will be propelled by the winds like shrapnel. Windows at the ends of corridors, particularly those facing south, southwest, and west, are very dangerous. They will probably be blown down the corridor in a wind tunnel effect.
(b) Windward side walls, which usually are on the south and west, receive the full strength of the winds. It is assumed that windows on these sides will be broken and blown into the rooms on the windward side. This often results in increased air pressure, which aids in raising the roof.
(c) Wind tunnels occur in unprotected corridors facing the oncoming winds, which usually come from the south or west. Openings facing these directions allow the winds to penetrate into interior spaces. The winds apparently occupy almost the entire volume of such a wind tunnel, as debris marks have been found to cover the full height of the walls. If entrances are baffled with a solid massive wall, this effect is much less serious.
(d) Lightweight roofs such as steel deck plate, wood planks, or plywood will usually be lifted up by the wind and partially carried away, with some roof debris falling below.
(e) Heavier roofs, especially precast concrete planks, may lift up and move slightly and then fall, but not always returning to their original support location. If the support has collapsed, the heavy roof may fall into the area below.
(f) Long-span rooms almost always have high ceilings. The exterior walls are usually higher than the typical one-story wall. Often these walls, especially those with southern or western exposures, will collapse into the long span. If they are load-bearing walls, the roof will cave in on the area also. Avoid rooms such as gyms, auditoriums and cafeterias.
(g) Load-bearing walls are the sole support for floors or roofs above. If winds cause the supporting walls to fail, part or all of the roof or floors above will collapse. The most dangerous locations in a building are usually along the south and west sides, and at all corners.
(h) Masonry construction is not immune to wall collapse. Most masonry walls are not vertically reinforced, and can fail when high horizontal forces occur, such as those caused by winds.
Effective Date: November 1, 2011
Prior Effective Dates: 7/1/79; 6/1/85; 6/15/92; 7/1/93; 9/1/95; 1/3/00; 9/1/05; 7/1/07