A. The ridge shingles should be attached with alternate overlaps, similar to the way a woven corner is detailed on a wall. The exposure should equal that of all regular courses of shingles. Note that longer nails will be necessary for the ridge shingles. Shingles on the sides of dormers need not be clipped at the top.

To keep the metal valley flashings lying flat, do not nail them directly to the roof sheathing. Instead, fasten them with clips nailed to the sheathing and locked into the rolled edge of the flashing. This allows the flashing to move with temperature changes. The shingles should not be nailed through the metal. Valley flashing should overlap 6...

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