Snap a chalkline 2 to 3 inches past the valley center on the top layer of shingles.
Flashing in a roof valley.
Closed valleys or open valleys.
Avoid the following common errors.
One of the details that varies between homes is the method of flashing the valley areas of the roof.
December 25 2018 drip edge metal valley flashing dormer chimney and kick out flashing shed water away from the connections between roofs walls chimneys and other building assemblies.
Roof mastic applied along sides of valley flashing.
Fasteners placed in the exposed center area.
Valley flashing is metal or sometimes peel and stick material that protects an important area on the roof where two slopes come together to form a valley.
Stop nailing 6 inches from the center.
There are two common methods for completing the flashing of a valley in a shingle roof system.
Properly sized and installed valley flashing is key to channeling water safely off the roof.
From drip edge to valley flashing.
Punctures in the center of the valley.
Closed cut valley fully replaced with new metal valley flashing.
Failure to extend the entire width of the metal valley flashing beyond the eave of the roof.
Shingle the other side of the valley the same way.
Roof one side of the valley running the shingles across it.
Some homeowners do not like the look of open valleys while others feel the metal accentuates the roof s shape particularly if copper or painted flashing is used.
This collection of 18 articles animations and videos identifies the critical roof flashing areas.