47.5 MB - The Whole Building Design Guide

are torch-applied, avoid overheating the conductors. For singleplymembranes, use self-adhering flashing strips, approximately 9inches wide at a minimum. Start the strips approximately 3 inchesfrom either side of the air terminal base plates. Use strips that areapproximately 3 feet long, separated by a gap of approximately 3inches (see Figure 3-98).Figure 3-98: Plan showing conductor attachmentAs an option to securing the conductors with stripping plies,conductor connectors that do not rely on prongs could be used(such as the one shown in Figure 3-99). However, the magnitudeof the dynamic loads induced by the conductor is unknown,and there is a lack of data on the resistanceprovided by adhesively-attached connectors. For thisreason, attachment with stripping plies is the preferredoption, because the plies shield the conductor fromthe wind. If adhesive-applied conductor connectorsare used, it is recommended that they be spaced moreclosely than the 3-foot spacing required by NFPA 780and UL 96A. Depending on wind loads, a spacing of 6to 12 inches on center may be needed in the corner regionsof the roof, with a spacing of 12 to 18 inches oncenter at roof perimeters (see ASCE 7 for the size ofcorner regions).Figure 3-99:Adhesively-attached conductorconnector that does not use prongs3-118 MAKING CRITICAL FACILITIES SAFE FROM High Wind