Specification:Mechanical repair of metal roofing

__NUMBEREDHEADINGS__ =GENERAL=

DESCRIPTION
 This specification provides guidance for appropriate mechanical repair of metal roofing. This specification has been developed for use on historic properties (defined as any district, site, building, structure, or object that is listed in or eligible for listing in the National Register of Historic Places) and provides an overview of accepted practices. All work described herein and related work must conform to the Secretary of Interior’s Standards for the Treatment of Historic Properties. The Contractor shall provide all labor, materials, equipment, and operations required to complete the rehabilitation work indicated herein. All work described herein and related work must have the approval of a Cultural Resources Manager, Conservator, Historic Architect, or other professional who meets the standards outlined in the Secretary of the Interior’s Standards – Professional Qualifications Standards pursuant to 36 CFR 61. Such person is referred to in this document as the Architect. The Architect will provide site-specific specifications, when appropriate.  

SECTION INCLUDES
 Seam and Hole Repairs of Existing Metal Roofing</li> Reattachment of Loose Metal</li> </ol>

RELATED SECTIONS
<ol type="A"> Section 05010 – Historic Metals</li> Section 07631 – Flashing, Gutters and Drains</li> </ol>

SUBMITTALS
<ol type="A"> Schedule of Repair:  The Contractor shall submit annotated drawings and/or photographs showing areas of sheet metal roofing to be repaired, keyed to indicate the types of repairs to be performed. This document shall be reviewed and approved with the Architect at the site prior to beginning operations.</li> The initial field survey shall include photographs. The contractor shall be prepared to submit photo documentation before, during, and after the work.</li> </ol> </li> Product Literature:  Submit manufacturer's product data for roofing metal. Product data shall indicate material composition, gauge and finish. Fabrication and installation details shall be included. </li> Material Samples: Submit 12 inch by 12 inch samples of each type and weight of metal, rivets, nails, and fasteners.</li> </ol> </li> </ol>

QUALITY ASSURANCE
<ol type="A"> Work Experience: The Contractor shall have at least seven years experience in the fabrication and installation of copper, lead-coated copper and terne metal roofing and shall have completed at least three projects of similar size and scope of work within the previous three years.</li> Provide only products or materials of approved manufacturers. Do not change product or material suppliers during the course of the work.</li> The Contractor shall provide a standard two-year material and workmanship guarantee for roofing repairs. </li> </ol>

MOCK-UPS
<ol type="A"> Workmanship Samples: The Contractor shall submit one sample of each type of soldered sheetmetal joint required, to be prepared by the mechanic(s) proposed to work on the project. Joint samples shall be at least 12 inches long. Samples will be cut after submittal to verify that joints are fully sweated.</li> </ol>

DELIVERY, STORAGE AND HANDLING
<ol type="A"> Protect sheet metal materials from dents, bending, crimping and other mechanical damage during delivery and storage. Protect copper, terne and lead-coated metal from scratching and gouging of the surface coating during handling and installation. Damaged materials will not be acceptable.</li> </ol>

PROJECT / SITE CONDITIONS
<ol type="A"> <li>Roofing work shall not be performed in inclement weather, or when inclement weather is forecast. During field installation, all joints shall be soldered the same day they are formed to minimize the opportunity for contamination by dirt and moisture.</li> <li>The Contractor is responsible for protecting existing adjacent materials during the execution of the work. Provide all necessary protection and work procedures to avoid damage to existing material assemblies not a part of the work of this Section. At a minimum, the Contractor shall: <ol> <li>Protect adjacent woodwork during soldering operations. Maintain fire extinguishing equipment in the immediate vicinity when soldering is underway.</li> <li>Provide sturdy, weather-proof protection at all areas exposed during roof installation. Do not leave interior spaces exposed to the elements overnight. The Contractor shall maintain adequate supplies of protective materials on site at all times in the event of sudden weather changes.</li> <li>Protect adjacent membrane roof surfaces during metal roof installation. Provide sturdy, heat-resistant protection in areas adjacent to soldering operations. Any damage to roofs shall be repaired to a water-tight condition by the Contractor at no additional charge to the Owner.</li> </ol> </li> <li>Coordinate the work of this Section with the masonry restoration, window / door restoration, cornice and membrane roofing work included in the project to avoid delays.</li> <li>Provide barriers around work area to exclude and protect passers-by during overhead work.</li> </ol> =PRODUCTS=

TERNE COATED STAINLESS ROOFING
<ol type="A"> <li>Patching material for Terne coated stainless roofing shall be Type 304 stainless steel sheet coated with 50 percent zinc / 50 percent tin alloy to a thickness of 20 microns. Roofing material shall be 28 gauge (.015) with a mill-applied shop coat. </li> <li>Solder for terne-coated metal shall be 100 percent tin complying with ASTM B 32-96.</li> <li>Flux shall be zinc chloride.</li> <li>Cleats shall be two inches wide pre-formed cleats or field-fabricated from stainless steel flat stock coated with 50 percent zinc / 50 percent tin alloy to a thickness of 20 microns to match the roofing to be fastened.</li> <li>Fasteners for cleats shall be stainless steel nails. Nails shall be 0.109 inch gauge minimum, large head ring shank or annular ring, and of sufficient length to penetrate wood roof deck not less than one inch. </li> </ol>

LEAD-COATED COPPER ROOFING MATERIALS
<ol type="A"> <li>Patching material for lead-coated copper roofing shall be lead-coated copper meeting ASTM B101-96, Type I, Class A. Copper sheets shall be cold-rolled, 16 ounces per square foot, with 15 pound lead coating. </li> <li>Solder for lead-coated copper: 60 percent tin, 40 percent pig lead complying with ASTM B32-96.</li> <li>Flux for lead-coated copper shall be FS-O-F-506C or manufacturer’s standard muriatic or phosphoric acid type, neutralized with zinc. </li> <li>Fasteners: Stainless steel or copper nails.</li> <li>Sealant: One-part polysulfide or silicone sealant  to be approved by the Architect.</li> <li>Bituminous Plastic Cement: FS SS-C-153C, Type II.</li> </ol>

COPPER ROOFING
<ol type="A"> <li>Patching material for copper roofing shall be copper, ASTM B 370, Grade H00 (cold rolled), 24 ounce (0.0323inch). Gutter pans to be 8 ft. lengths minimum. </li> <li>Solder: 50 percent tin, 50 percent pig lead complying with ASTM B32 for copper and galvanized sheet metal.</li> <li>Flux: Muriatic acid neutralized with zinc, or approved commercial brand of flux for copper. Note: thoroughly wash off all flux after soldering.</li> <li>Slip sheet: Rosin-surfaced building paper, minimum five pounds per 100 square ft.</li> <li>Cleats shall be same metal and weight as metal being cleated, unless otherwise indicated on the Drawings. Cleats shall be two inches wide by three inches long.</li> <li>Nails for copper cleats shall be copper, 0.109 inch gauge minimum, large head ring shank or annular ring, and of sufficient length to penetrate wood roof deck not less than one inch. </li> <li>Rivets: Shall be &quot;Pop&quot; type, stainless steel rivets with stainless steel mandrels, 1/8 inch diameter by 1/4 inch long. </li> <li>Liquid metal for sealing of rivet shall be approved by Architect. </li> </ol> =EXECUTION=

GENERAL
<ol type="A"> <li>Inspect the roof surface with the Architect prior to beginning work. Mark locations of all seam and hole repairs. Inspect the roof for conditions that may prevent completion of the repairs in an appropriate manner. Notify the Architect immediately of any unsuitable conditions.</li> </ol>

REPAIRING DAMAGED SEAMS
<ol type="A"> <li>Clean seam to be repaired of all dirt, debris, dust, grease, and other contaminants. Clean all existing roofing mastic from seam and adjacent roof surfaces. Ensure seam is clean and dry. </li> <li>Clean surrounding metal to bright by removing all paint and other possible contaminants and brushing with non-metallic scouring pads.</li> <li>Fashion TCS patch two to three inches wide by slightly longer than length of open seam with rounded corners, or as required to extend patch one inch beyond open seam. Shape patch with 3/4 inch wide flange around full perimeter. Rivet and solder to existing roofing. Seal rivets with specified sealant.</li> </ol>

REPAIRING HOLES IN METAL ROOFING
<ol type="A"> <li>Identify the metal that the roof is made of and fashion a piece of the same metal to make a patch. Cut a patch at least two inches larger than the damaged area on all sides. Round all corners. Fold the edges under approximately 1/2 inch. Sand the folded edges to bright metal. </li> <li>Clean the damaged area with all-purpose cleaner and let dry, wire brush with a non-ferrous brush to remove debris. Put flux both on the surface to be patched and along the folded edges of the patch. </li> <li>Heat patch thoroughly with soldering iron. Hold solder to the seam, and use a soldering iron to heat solder until it melts and runs under the patch. Follow the patch all the way around with the solder and soldering iron. </li> </ol>

FINAL REPORT
<ol type="A"> <li>The Contractor shall submit a final report of the roof work including all approved submittals, as-built drawings and photographs taken before, during and after the repairs. </li> </ol>