A woven valley shingle installation is one where the shingles from both sides of the roof valley extend over the valley and weave together overlapping courses alternately. All of the shingle rows will need to be lined up correctly.
Pros of Woven Valley Shingle Installations
Water has a small chance of even getting up under the woven valley shingles even though it flows in either direction. The woven valley shingles can be used on different types of roof shapes. These shingles also work best in regions where there is high winds since the tabs interlock to shield the valley. Woven valley shingles not only look better than open valley shingles, but they work better too. They can withstand the buildup of ice and snow as long as they have an ice and water shield installed under the valleys and eaves.
Cons of Woven Valley Shingle Installations
The woven valley shingles take longer to install since both sides of the valley need to be ran at the same time. The woven valley shingles are also difficult to repair. If the shingles are too thick, they are unable to be woven. Woven valley shingles have a tendency to sometimes trap leaves, granules and dirt in the valley. Woven valley shingles are a better choice for lower slopes.