At a minimum, EHPAs shall be designed for wind loads in accordance with ASCE 7, Minimum Design Loads for Buildings and Other Structures, Risk Category IV (Essential Buildings). Openings shall withstand the impact of wind-borne debris missiles in accordance with the impact and cyclic loading criteria per ASTM E 1886, and ASTM E 1996 or SBC/SSTD 12. Based on a research document, Emergency Shelter Design Criteria for Educational Facilities, by the University of Florida for the DOE, it is highly recommended by the department that the shelter be designed using the map wind speed plus 40 mph.
Materials used for walls, roofs, windows, louvers, and doors shall be certified for resistance to missile impact criteria.
The glazed openings or permanent protective systems over glazed openings shall be designed for cyclic loading.
Roof decks shall be cast-in-place 4-inch (102 mm) or more, normal weight concrete. Concrete decks shall be waterproof. Systems other than cast-in-place concrete shall have adequate bearing, anchorage against wind uplift, diaphragm action, and resistance to rain that are equivalent to a cast-in-place system.
Roof openings (e.g., HVAC fans, ducts, skylights) shall be designed to meet the wind load and missile impact criteria.
Roofs shall have adequate slope and drains sized for normal use and shall have emergency overflow scuppers.
Parapets shall satisfy the wind load and missile impact criteria; roof overhangs shall resist uplift forces.
All unprotected window assemblies and their anchoring systems shall be designed and installed to meet the wind load and missile impact criteria.
Windows may be provided with permanent protective systems, provided the protective system is designed and installed to meet the wind load and missile impact criteria and completely covers the window assembly and anchoring system.
All exterior and interior doors subject to possible wind exposure and/or missile impact shall have doors, frames, anchoring devices, and vision panels designed and installed to resist the wind load and missile impact criteria or such doors, frames, anchoring devices, and vision panels shall be covered with permanent protective systems designed and installed to resist the wind load and missile impact criteria.
The exterior envelope, louvers over air intakes and vents, and gooseneck-type intakes and vents of EHPAs shall be designed and installed to meet the wind load and missile impact criteria.
Roof mounted HVAC equipment shall have a 12-inch-high (305 mm) curb around the roof opening and be designed to prevent the entry of rain water.
Foundations shall be designed to resist all appropriate loads and load combinations, including overturning moments due to wind. The floor elevation and necessary life safety and other emergency support systems of EHPAs shall be elevated above the maximum storm surge inundation elevation associated with a Category 4 hurricane event. Storm surge elevations shall be identified by the most current edition of the regional Sea Lake and Overland Surges from Hurricanes (SLOSH) studies and atlases.