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Orange County Architectural Renovations Smith Sinnett / 2023036 <br />Hillsborough, NC Orange County Asset Management Services <br />SHEET METAL FLASHING AND TRIM 07 62 00 - 3 <br />1. Do not use lapped or bayonet-type (nested) joints for sheet metal fabrications. <br />2. Fabricate concealed splice plates of specific size and profile to maintain lines and form of <br />fabricated work. <br />3. Provide a 1/8" gap between fabricated units at butt joints. <br />G. Separate metal from noncompatible metal or corrosive substrates by coating concealed surfaces at <br />locations of contact with asphalt mastic or other permanent separation as recommended by manufacturer. <br />H. Conceal fasteners and expansion provisions where possible. Exposed fasteners are not allowed on faces <br />of sheet metal exposed to public view. <br />I. Size: As recommended by SMACNA manual or sheet metal manufacturer for application but never less <br />than thickness of metal being secured. <br />2.4 SHEET METAL FABRICATIONS <br />A. General: Fabricate sheet metal items in thickness or weight needed to comply with performance <br />requirements but not less than that listed below for each application and metal. <br />B. Base Flashing: Fabricate from the following material: <br />1. .040, Aluminum Sheet <br />C. Counterflashing: Fabricate from the following material: <br />1. .040, Aluminum Sheet <br />PART 3 - EXECUTION <br />3.1 EXAMINATION <br />A. Examine substrates and conditions under which sheet metal flashing and trim are to be installed and <br />verify that Work may properly commence. Do not proceed with installation until unsatisfactory <br />conditions have been corrected. <br />3.2 INSTALLATION <br />A. General: Unless otherwise indicated, install sheet metal flashing and trim to comply with performance <br />requirements, manufacturer’s installation instructions, and SMACNA’s "Architectural Sheet Metal <br />Manual." Anchor units of Work securely in place by methods indicated, providing for thermal expansion <br />of metal units; conceal fasteners where possible, and set units true to line and level as indicated. Install <br />Work with laps, joints, and seams that will be permanently watertight and weatherproof. <br />B. Install exposed sheet metal Work that is without excessive oil canning, buckling, and tool marks and that <br />is true to line and levels indicated, with exposed edges folded back to form hems. Install sheet metal <br />flashing and trim to fit substrates and to result in waterproof and weather-resistant performance. Verify <br />shapes and dimensions of surfaces to be covered before fabricating sheet metal. <br />C. Sealed Joints: Form nonexpansion, but movable, joints in metal to accommodate elastomeric sealant to <br />comply with SMACNA standards and as follows: <br />1. Fabricate sealed joints in prefinished sheet metal with butt joints and concealed splice plates. <br />Install silicone elastomeric sealant between exposed metal work and splice plates, and rivet one <br />side of fabricated unit to splice plate for strength. <br />a. Do not use lapped or bayonet-type (nested) joints for sheet metal fabrications. <br />2. Fabricate concealed splice plates of specific size and profile to maintain lines and form of <br />fabricated work. <br />3. Provide a 1/8" gap between fabricated units at butt joints. <br />D. Separations: Separate metal from non-compatible metal or corrosive substrates by coating concealed <br />surfaces, at locations of contact, with asphalt mastic or other permanent separation as recommended by <br />manufacturer. <br />Docusign Envelope ID: 52FACC74-DA96-491B-B0B8-04AC3961737D