Flashing In A Roof Valley

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.

Flashing in a roof valley.

Shingle the other side of the valley the same way. From drip edge to valley flashing. Avoid the following common errors. Closed cut valley fully replaced with new metal valley flashing.

This collection of 18 articles animations and videos identifies the critical roof flashing areas. Properly sized and installed valley flashing is key to channeling water safely off the roof. One of the details that varies between homes is the method of flashing the valley areas of the roof. Fasteners placed in the exposed center area.

To understand what makes a valley either closed or open it is important to understand how a valley is constructed. Snap a chalkline 2 to 3 inches past the valley center on the top layer of shingles. Punctures in the center of the valley. There are two common methods for completing the flashing of a valley in a shingle roof system.

Lay one and two tab shingles as you near the valley so full size shingles will run across the valley. Stop nailing 6 inches from the center. That flashing is left exposed so the roof has visible lines of metal running down the valley. Failure to extend the entire width of the metal valley flashing beyond the eave of the roof.

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. Roof one side of the valley running the shingles across it.