Valley linings shall be installed in accordance with the manufacturer's instructions before applying shingles. Valley linings of the following types shall be permitted:
- For open valleys (valley lining exposed) lined with metal, the valley lining shall be not less than 24 inches (610 mm) wide and of any of the corrosion-resistant metals in Table 1507.2.8.2.
- For open valleys, valley lining of two plies of mineral-surfaced roll roofing complying with ASTM D3909 or ASTM D6380 shall be permitted. The bottom layer shall be 18 inches (457 mm) and the top layer not less than 36 inches (914 mm) wide.
- For closed valleys (valleys covered with shingles), valley lining of one ply of smooth roll roofing complying with ASTM D6380, and not less than 36 inches (914 mm) wide or types as described in Item 1 or 2 above shall be permitted. Self-adhering polymer modified bitumen underlayment bearing a label indicating compliance with ASTM D1970 shall be permitted in lieu of the lining material.
VALLEY LINING MATERIAL
|Cold-rolled copper||0.0216 in.||—||ASTM B370, 16 oz. per square ft.|
|Galvanized steel||0.0179 in.||26 (zinc-coated G90)||—|
|High-yield copper||0.0162 in.||—||ASTM B370, 12 oz. per square ft.|
|Lead-coated copper||0.0216 in.||—||ASTM B101, 16 oz. per square ft.|
|Lead-coated high-yield copper||0.0162 in.||—||ASTM B101, 12 oz. per square ft.|
|Painted terne||—||—||20 pounds|
|Zinc alloy||0.027 in.||—||—|
For SI: 1 inch = 25.4 mm, 1 pound = 0.454 kg, 1 ounce = 28.35 g, 1 square foot = 0.0929 m2.