What is the difference between a metal open valley and a woven or closed-cut valley?
A. A woven valley is when the shingles from both sides of the valley extend across the valley and are woven together by overlapping alternate courses as they are applied. A closed-cut valley is when the shingles from one side of the valley extend across the valley while the other side is trimmed back approximately 2 inches from the centerline. DeVore Roofing recommends the open valley method which is to install a metal valley with a center rib and to then cut the shingles on both sides of the valley back from the center rib about 2 inches, exposing the valley metal. The reason for this is that the metal channel that is created will allow the water to run smoothly down to the gutter. Also, the metal valley will stay intact for the life of your shingles. The woven or closed-cut valley system will become unsightly and wear out first because all the water from your roof drains there. The life of you roof system will be shortened because of worn valley shingles.
