47.5 MB - The Whole Building Design Guide

and a layer of MEPS separate the occupants from the impact ofwind-borne debris that can easily penetrate such a wall and causeinjury.Stucco: Wind performance of traditional stucco walls is similar tothe performance of EIFS, as shown in Figure 3-57. In several areasthe metal stud system failed; in other areas the gypsum sheathingblew off the studs; and in other areas, the metal lath blew off thegypsum sheathing. The failure shown in Figure 3-57 illustrates theimportance of designing and constructing wall framing (includingattachment of stud tracks to the building and attachment of thestuds to the tracks) to resist the design wind loads.Figure 3-57:The stucco wall failure wascaused by inadequateattachment betweenthe stud tracks and thebuilding’s structure.Hurricane Ivan (Florida,2004)Metal wall panels: Wind performance of metal wall panels is highlyvariable. Performance depends on the strength of the specifiedpanel (which is a function of material and thickness, panel profile,panel width, and whether the panel is a composite) and the adequacyof the attachment (which can either be by concealed clipsor exposed fasteners). Excessive spacing between clips/fastenersis the most common problem. Clip/fastener spacing should bespecified, along with the specific type and size of fastener. Figures3-14 and 3-58 illustrate metal wall panel problems. At the schoolshown in Figure 3-58 (which was being used as a shelter), the3-68 MAKING CRITICAL FACILITIES SAFE FROM High Wind