What You Need to Know About Valleys
A proper open valley application:
A W or V shaped piece of metal is installed on top of the ice and water shield.
Shingles are cut along the line created by the 2nd row of the ice and water and the metal remains “open” to carry the water off the roof.
Two common metal valley designs include:
W- where a bump is bent into the center to prohibit water from entering under the shingles
You can also have valleys without metal and ice and water with still having correct installation. These are called closed valleys.
Two common closed valley styles include:
Woven style - Where shingles are overlapped across the valley on the opposite slopes
Closed Cut - This is where the shingles look like the roof is coming together and forming a straight line down the middle
Most installation errors are where we see the valley installed backwards. The shingles are going against the water flow which is forcing the water to go downwards into the attic space instead of flowing through the valley into your gutter system.When this happens we are forced to take out the whole valley, install an ice and water shield, and then replace the shingles with matching roof material presented on the roof.
If you have anymore questions on proper valley replacement or you are concerned about your valleys. Please feel free to contact us here.