Flashing In A Roof Valley

Stop nailing 6 inches from the center.

Flashing in a roof valley.

One of the details that varies between homes is the method of flashing the valley areas of the roof. From drip edge to valley flashing. Roof one side of the valley running the shingles across it. Snap a chalkline 2 to 3 inches past the valley center on the top layer of shingles.

Lay one and two tab shingles as you near the valley so full size shingles will run across the valley. Closed valleys or open valleys. Properly sized and installed valley flashing is key to channeling water safely off the roof. Punctures in the center of the valley.

Fasteners placed in the exposed center area. Closed cut valley fully replaced with new metal valley flashing. To understand what makes a valley either closed or open it is important to understand how a valley is constructed. 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.

Shingle the other side of the valley the same way. Roof mastic applied along sides of valley flashing. That flashing is left exposed so the roof has visible lines of metal running down the valley. 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. There are two common methods for completing the flashing of a valley in a shingle roof system.