47.5 MB - The Whole Building Design Guide

Figure 3-87:Significant interior waterdamage and facilityinterruption occurredafter the standing seamroof blew off. HurricaneMarilyn (U.S. VirginIslands, 1995)In order to avoid the possibility of roofing components blowingoff and striking people arriving at a critical facility during a storm,the following roof systems are not recommended: aggregate surfacingseither on BUR (shown in Figure 3-12), single-plies (shownin Figure 3-9), or SPF; lightweight concrete pavers; cementitiouscoatedinsulation boards; slate; and tile (see Figure 3-88). Evenwhen slates and tiles are properly attached to resist wind loads,their brittleness makes them vulnerable to breakage as a resultof wind-borne debris impact. The tile and slate fragments can beblown off the roof, and fragments can damage other parts of theroof causing a cascading failure.Figure 3-88:Brittle roof coverings,like slate and tile, can bebroken by missiles, andtile debris can break othertiles. Hurricane Charley(Florida, 2004)3-110 MAKING CRITICAL FACILITIES SAFE FROM High Wind