47.5 MB - The Whole Building Design Guide

To enhance the wind performance of LPS, the following arerecommended: 10Parapet attachment: When the parapet is 12 inches high or greater,it is recommended that the air terminal base plates and conductorconnectors be mechanically attached with #12 screwsthat have minimum 1¼-inch embedment into the inside face ofthe parapet nailer and are properly sealed for watertight protection.Instead of conductor connectors that have prongs, it isrecommended that mechanically attached looped connectors beinstalled (see Figure 3-97).Figure 3-97: Thisconductor was attached tothe coping with a loopedconnector. HurricaneKatrina (Mississippi, 2005)Attachment to built-up, modified bitumen, and single-ply membranes:For built-up and modified bitumen membranes, attach the airterminal base plates with asphalt roof cement. For single-ply membranes,attach the air terminal base plates with pourable sealer (ofthe type recommended by the membrane manufacturer).In lieu of attaching conductors with conductor connectors, it isrecommended that conductors be attached with strips of membraneinstalled by the roofing contractor. For built-up andmodified bitumen membranes, use strips of modified bitumencap sheet, approximately 9 inches wide at a minimum. If strips10. Discussion is based on Rooftop Attachment of Lightning Protection Systems in High-Wind Regions—Hurricane Katrina Recover Advisory(May 2006, Revised July 2006).MAKING CRITICAL FACILITIES SAFE FROM High Wind3-117