How To Flash A Roof Valley

Make sure to cover the gap at the bottom of the raised ridge.

How to flash a roof valley.

Roof one side of the valley running the shingles across it. Use 1 inch galvanized roofing nails. Protect the eave from ice dams and sideways rain step one in steep slope roofing is the edge flashing. Stop nailing 6 inches from the center.

Details concrete masonry roofing wrb flashing. Two ways to flash roof edges. One common method is to lay the edge metal under the eaves membrane and over the rake. Step 6 install the flashing.

Fold the top of the flashing over the ridge. Attach the flashing panel in place at the bottom. Lay one and two tab shingles as you near the valley so full size shingles will run across the valley. 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. Snap a chalkline 2 to 3 inches past the valley center on the top layer of shingles. Remember to caulk the underside of the flashing with a sealant. 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.

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