Open Valley Roof

With a clean valley you can lay down some peel and stick roofing membrane.

Open valley roof.

There are three ways to roof valleys. Open valleys may be susceptible to water backup if the cut off shingles are not properly trimmed potentially causing roof leaks. Regardless of the method you choose do not drive nails within 6 inches or so of the valley center or you will provide an unwanted pathway for water. The metal is usually pre painted to best complement the shingles color blend.

For an open valley a sheet of metal usually steel sometimes copper is fastened to the roof deck. And either an organic or modified underlayment depending on whether tiles or shingles are being installed. After the self adhering underlayment is installed across the valley a pre bent metal valley lining is installed. An open valley has a gap usually about 6 inches between the tile or shingles at the valley area.

First clean the debris out of the valley including sawdust nails and whatever else is in there. However it is said that provided the rest of the roofing shingles were properly installed and are performing properly open valleys will perform better over time than closed valleys. The valley lining whether asphalt or metal should have 6 inches open at the top 3 inches on either side of the valley centerline and increase by 1 8 inch for each foot of valley length to accommodate the greater flow further down the valley. Roofing shingles are installed then cut and sealed where they overlap the metal channel.

Fold the top over the. Open valleys a roof using the open valley style involves placing a v or w shaped piece of metal usually galvanized or sometimes copper in the seam of the valley and then covered with a base sheet such as 30lb. All three work well but check which is preferred by your local building department. Fold the top over the roof ridge and cut the bottom along the drip edge metal.

Open metal closed cut and woven. With a clean valley you can lay down some peel and stick roofing membrane. What is an open valley roof.