06-28-08 Building Codes Appeals Board minutes

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ROOF ASSEMBLIES AND ROOFTOP STRUCTURES by an approved agency shall be required by the building official to detennine the character, quality and limitations of applica- tion of the materials. 1506.4 Product identification. Roof-covering materials shall be delivered in packages bearing the manufacturer's identify- ing marks and approved testing agency labels required in accordance with Section 1505. Bulk shipments of materials shall be accompanied with the same information issued in the form of a certificate or on a bill oflading by the manufacturer. SECTION 1507 REQUIREMENTS FOR ROOF COVERINGS 1507.1 Scope. Roof coverings shall be applied in accordance with the applicable provisions of this section and the manufac- turer's installation instructions. 1507.2 Asphalt shingles. The installation of asphalt shingles shall comply with the provisions of this section. .. 1507.2.1 Deck requirements. Asphalt shingles shall be fas- tened to solidly sheathed decks. 1507.2.2 Slope. Asphalt shingles shall only be used on roof slopes of two units vertical in 12 units horizontal (17 -per- cent slope) or greater. For roof slopes from two units vertical in 12 units horizontal (17-percent slope) up to four units ver- tical in 12 units horizontal (33-percent slope), double underlayment application is required in accordance with Section 1507.2.8. 1507.2.3 UnderIayment. Unless otherwise noted, required underlayment shall conform to ASTM D 226, Type I, ASTM D 4869, Type I, or ASTM D 6757. 1507.2.4 Self-adhering polymer modified bitumen sheet. Self-adhering polymer modified bitumen sheet shall com- ply with ASTM D 1970. ,."...-, 1507.2.5 Asphalt shingles. Asphalt shingles shall have self-seal strips or be interlocking and comply with ASTM D I 225 or ASTM D 3462. Asphalt shingle packaging shall bear labeling indicating compliance with ASTM D 3161 or a list- ing by an approved testing agency in accordance with the ~ requirements of Section 1609.5.2. {\ 1507.2.6 Fasteners. Fasteners for asphalt shingles shall be galvanized, stainless steel, aluminum or copper roofmg nails, minimum 12 gage [0.105 inch (2.67 mm)] shank with a minimum 0.375 inch-diameter (9.5 mm) head, of a length to penetrate through the roofing materials and a minimum of 0.75 inch (19.1 mm) into the roof sheathing. Where the roof sheathing is less than 0.75 inch (19.1 mm) thick, the nails shall penetrate through the sheathing. Fasteners shall com- ply with ASTM F 1667. 1507.2.7 Attachment. Asphalt shingles shall have the min- imum number of fasteners required by the manufacturer and Section 1504.1. Asphalt shingles shall be secured to the roof with not less than four fasteners per strip shingle or two fas- teners per individual shingle. Where the roof slope exceeds 20 units vertical in 12 units horizontal (166-percent slope), 266 asphalt shingles shall be installed in accordance with the manufacturer's printed installation instructions for I steep-slope roof applications. 1507.2.8 Underlayment application. For roof slopes from two units vertical in 12 units horizontal (17-percent slope) and up to four units vertical in 12 units horizontal (33-per- cent slope), underlayment shall be two layers applied in the following manner. Apply a minimum 19-inch-wide (483 mm) strip of underlayment felt parallel with and starting at the eaves, fastened sufficiently to hold in place. Starting at the eave, apply 36-inch-wide (914 mm) sheets of underlayment overlapping successive sheets 19 inches (483 mm), by fastened sufficiently to hold in place. Distortions in the underlayment shall not interfere with the ability of the shingles to seal. For roof slopes of four units vertical in 12 units horizontal (33-percent slope) or greater, underlayment shall be one layer applied in the following manner. Underlayment shall be applied shingle fashion, parallel to and starting from the eave and lapped 2 inches (51 mm), fas- tened sufficiently to hold in place. Distortions in the underlayment shall not interfere with the ability of the shin- gles to seal. 1507.2.8.1 High wind attachment. Underlayment applied in areas subject to high winds (greater than 110 mph in accordance with Figure 1609) shall be applied with corrosion- resistant fasteners in accordance with the manufacturer's instructions. Fasteners are to be applied along the overlap at a maximum spacing of 36 inches (914 mm) on center. 1507.2.8.2 Ice dam membrane. In areas where there has I been a history of ice fonning along the eaves causing a backup of water, a membrane that consists of at least two layers of underlayment cemented together or of a self-adhering polymer modified bitumen sheet shall be used in lieu of normal underlayment and extend from the eave's edge to a point at least 24 inches (610 mm) inside the exterior wall line of the building. Exception: Detached accessory structures that con- tain no conditioned floor area. 1507.2.9 Flashings. Flashing for asphalt shingles shall comply with this section. Flashing shall be applied in accor- dance with this section and the asphalt shingle manufac- turer's printed instructions. 1507.2.9.1 Base and cap flashing. Base and cap flash- ing shall be installed in accordance with the manufac- turer's instructions. Base flashing shall be of either corrosion-resistant metal of minimum nominal 0.019-inch (0.483 mm) thickness or mineral-surfaced roll roofing weighing a minimum of 77 pounds per 100 square feet (3.76 kg/m2). Cap flashing shall be corro- sion-resistant metal of minimum nominal 0.019-inch (0.483 mm) thickness. 1507.2.9.2 Valleys. Valley linings shall be installed in accordance with the manufacturer's instructions before 2006 INTERNATIONAL BUilDING CODe8