A closed cut roof valley will have at least four layers of roof materials.
Roof hog valley.
There is usually a wall that this valley meets at the narrow end causing water to accumulate at.
The hog valley is much wider at the top than the bottom.
The open woven and closed cut methods are demonstrated.
Valleys are a prime leak area so it s important to be careful.
Closed cut shingle valleys work fine with strip shingles and laminated asphalt shingles.
In either situation the leaking roof valley can be fixed by removing affected shingles and structural elements and upgrading your roof s flashing.
Gaf mastering the roof chapter 12 this video demonstrates the proper installation technique for installing roofing valleys.
One layer each of felt underlayment mineral surfaced roll roofing and two layers of shingles.
A flashing is a transitional roofing material that connects the roof material to some other building material or to another part of the roof.