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WDi Project Number 240318 26-Nov-24 Public Works Service Center Re -roofing <br />2. Size: <br />a. Maximum sheet size permitted by application and job conditions. <br />b. Thickness: 60 mils <br />3. Color: White <br />2.3 ACCESSORIES <br />A. Fastener Plates: Manufacturer's standard <br />B. Induction Welding Plates: Aluminum/zinc alloy coated steel, specifically designed for induction welding applications. <br />C. Walkway Pads: Preformed resilient pads, recommended by roofing manufacturer, minimum 1/2 inch thick. <br />D. Mechanical Fasteners: Hot -dip galvanized or fluoropolymer coated steel, approved by roofing system <br />manufacturer, type and length suited to project conditions. <br />E. Other Accessories: <br />1. By manufacturer of roofing system, including adhesives, tapes, solvents, sealants, water cutoff mastic, and <br />prefabricated pipe flashings. <br />PART 3 - GENERAL <br />3.1 PREPARATION <br />A. Clean substrate of dust, debris, moisture, and other substances detrimental to roofing installation according to <br />roofing system manufacturer's written instructions. Remove sharp projections. <br />B. Prevent materials from entering and clogging roof drains and conductors and from spilling or migrating onto <br />surfaces of other construction. Remove roof -drain plugs when no work is taking place or when rain is forecast. <br />C. Complete terminations and base flashings and provide temporary seals to prevent water from entering completed <br />sections of roofing system at the end of the workday or when rain is forecast. Remove and discard temporary <br />seals before beginning work on adjoining roofing. <br />3.2 INSTALLATION <br />A. General Application: Install roofing system in accordance with roofing system manufacturer's instructions, NRCA <br />Manual, and approved Shop Drawings. <br />B. Insulation <br />1. Apply with long edges continuous and perpendicular to deck ribs. Stagger end joints in adjacent rows. Locate <br />ends over solid bearing. <br />2. Apply top layer with long edges perpendicular to those of base layer, with joints staggered in adjacent rows. <br />Offset joints from those in base layer. <br />3. Mechanically fasten to substrate in manufacturer's recommended fastening pattern. <br />4. Fit insulation to other boards at perimeter and around penetrations with maximum 1/4 inch voids. <br />C. Cover Board <br />1. Apply panels with long edges continuous and perpendicular to direction of insulation. Stagger end joints in <br />adjacent rows. Offset joints from those in insulation. <br />2. Mechanically fasten to substrate in manufacturer's recommended fastening pattern. <br />3. Fit panels to other panels and at perimeter and around penetrations with maximum 1/4 inch voids. <br />D. Roof Membrane <br />1. Position sheets without stretching; minimize wrinkles. Allow membrane to relax before proceeding, <br />2. Provide minimum 5-1/2 inch lap at joints between adjacent sheets. <br />3. Splice sheets by heat welding method. <br />4. Induction Welded Membrane: Fasten membrane using membrane Manufacturer's recommended induction <br />plates, fasteners, fastener spacing, and procedures. <br />5. Fasten membrane to perimeter nailers with fasteners spaced as recommended by roofing Manufacturer. <br />E. Daily Seal: <br />1. Ensure that water does not flow beneath completed sections of roof. <br />2. Temporarily seal loose edge of membrane with night seal when weather is threatening. <br />3. When work is resumed, pull sheet free before continuing installation. <br />Polyvinyl Chloride Roofing 6 of 7 Section 07 5419 <br />