47.5 MB - The Whole Building Design Guide

For critical facilities located in tornado-prone regions (as definedin Section 3.2.2), the following are recommended:m Incorporate a shelter within the facility to provide occupantprotection. For shelter design, FEMA 361 criteria arerecommended.m For interior non-load-bearing masonry walls, see therecommendations given in Section 3.3.3.3.m Brick veneer, aggregate roof surfacing, roof pavers, slate, andtile cannot be effectively anchored to prevent them frombecoming missiles if a strong or violent tornado passes neara building with these components. To reduce the potentialnumber of missiles, and hence reduce the potential forbuilding damage and injury to people, it is recommended thatthese materials not be specified for critical facilities in tornadoprone regions.m For hospitals, nursing homes, and other critical facilitieswhere it is desired to minimize disruption of operations fromnearby weak tornadoes and from strong and violent tornadosthat are on the periphery of the facility, the following arerecommended:1) For the roof deck, exterior walls, and doors, follow therecommendations given in Sections 3.4.2 and 3.4.3.2) For exterior glazing, specify laminated glass windowassemblies that are designed to resist the test Missile E loadspecified in ASTM E 1996, and are tested in accordance withASTM E 1886. Note that missile loads used for designingtornado shelters significantly exceed the missile loads usedfor designing glazing protection in hurricane-prone regions.Missiles from a strong or violent tornado passing near thefacility could penetrate the laminated glazing and result ininjury or interior damage. Therefore, to increase occupantsafety, even when laminated glass is specified, the facilityshould also incorporate a shelter as recommended above.MAKING CRITICAL FACILITIES SAFE FROM High Wind3-129