47.5 MB - The Whole Building Design Guide

3.3.3 Building EnvelopeThe following section highlights the design considerations forbuilding envelope components that have historically sustained thegreatest and most frequent damage in high winds.3.3.3.1 Exterior DoorsFor further general information on doors,see “Fenestration Systems” in the NationalInstitute of Building Sciences’ BuildingEnvelope Design Guide (www.wbdg.org/design/envelope.php)This section addresses primary and secondaryegress doors, sectional (garage) doors, androlling doors. Although blow-off of personneldoors is uncommon, it can cause seriousproblems (see Figure 3-29). Blown-off doorsallow entrance of rain and tumbling doorscan damage buildings and cause injuries.Particular attention should be given tothe design and installation of fire stationapparatus bay doors which have beenblown-in or blown-out frequently (seeFigure 3-30). If doors blow inward, theycan damage fire engines and ambulancesand impair emergency response.Blown off sectional and rolling doors are quite common. Thesefailures are typically caused by the use of door and track assembliesthat have insufficient wind resistance, or by inadequateattachment of the tracks or nailers to the wall. At the relativelynew fire station shown in Figure 3-30, twoof the windward doors were pushed out oftheir tracks. At the third door, the track waspushed out from the nailer. With the collapseof these doors, the apparatus bay wasfully pressurized. Because the connectionsbetween the trusses and the beam were tooweak to accommodate the uplift load, theentire roof structure over the apparatus bayblew off.See Section 3.4.3.1 for critical facilities located in hurricaneproneregions.Loads and ResistanceThe IBC requires that the door assembly (i.e., door, hardware,frame, and frame attachment to the wall) be of sufficient strengthto resist the positive and negative design wind pressure. Designprofessionals should require that doors comply with windload testing in accordance with ASTM E 1233. Design profes-3-48 MAKING CRITICAL FACILITIES SAFE FROM High Wind