Specifications include, but are not limited to: Flashing – Install flashings to seal against leakage at all intersections of different roof planes, all abutments of the roof against adjoining walls, and all projections through the roof surface such as chimneys and vent pipes. All eave, rake, step and counter flashing shall be copper. Chimney flashing shall extend up the chimney to a height not less than 3”, up the roof slope to a point equal in height to the flashing on the chimney but never less than 1 1/2 times the Certi-label shake/shingle exposure. Manufactured step-flashing: 5" x 7" shingle = 2 1/2" wall, 2 1/2" roof 8" x 12" shakes = 4" wall, 4" roof. Valley flashing – Metal valleys should be center-crimped copper and should extend not less than 11" on each side of the valley centerline. Shingles should not be applied with their grain parallel to the valley centerline and those extending into the valley should be cut at the correct angle