0053 Roof Valleys Open and Closed - Roofing - Steep Roof Flashings - Valley Flashings -

Image Text: Open valley: with a metal flashing > the valley should be 4-6 inches wide at the top and should widen out 1/8 inch per foot as you move down the valley > Closed valley: still requires roll roofing or felt underneath > this is a closed cut valley > see following illustrations for installation details