How To Flash A Roof Valley

Cut the bottom edge and fold it down over the drip edge.

How to flash a roof valley.

Roof one side of the valley running the shingles across it. Stop nailing 6 inches from the center. Details concrete masonry roofing wrb flashing. Fold the top of the flashing over the ridge.

Protect the eave from ice dams and sideways rain step one in steep slope roofing is the edge flashing. Step 6 install the flashing. Shingle the other side of the valley the same way. Two ways to flash roof edges.

Use 1 inch galvanized roofing nails. Make sure to cover the gap at the bottom of the raised ridge. Lay the flashing down in the roof valley and start at the lower end of the roof. Lay one and two tab shingles as you near the valley so full size shingles will run across the valley.

One common method is to lay the edge metal under the eaves membrane and over the rake. Snap a chalkline 2 to 3 inches past the valley center on the top layer of shingles. To splice the pieces add roofing cement to the lower piece and install the upper piece with at least a six inch. Now nail this first flashing at both its far ends.

Install valley battens on both ends of the roof valley then attach first flashing 3 4 inches over the roof flange and another 3 4 inches over the fascia if any is present.