Base-Sheet-Fastener-7-Inch.pdf

This is a technical drawing specification document for base sheet fastener placement on built-up roofing systems, applicable to state and local construction projects. The specification details the installation requirements for attaching base sheets to roof decking using approved fasteners and discs on lightweight concrete substrates with Tremco materials. Fasteners must be spaced 7 inches on center along sidelaps and in two equally staggered rows down the longitudinal center of the sheet, positioned 12 inches from each edge. The specification mandates increased fastening density at perimeter edges, requiring a 70 percent increase, and at corners, requiring a 160 percent increase, in accordance with FM Global Loss Prevention Data Sheets 1-28 and 1-29. Additional fastener rows must be added and fasteners per row increased as needed based on unit area calculations, with a minimum spacing requirement of 4 inches on center.

The drawing is designated as Drawing No. 15 and provides visual reference for base sheet width measurements and fastener placement intervals. This specification applies to hot or cold base sheet applications using specified Tremco products and fasteners with plates. No pricing terms, contract award dates, renewal options, or project timelines are included in this technical drawing document.