Open Valley On A Roof

Pros of open valley shingle installation.

Open valley on a roof.

With a clean valley you can lay down some peel and stick roofing membrane. Stop nailing 6 inches from the center. Roof one side of the valley running the shingles across it. Lay one and two tab shingles as you near the valley so full size shingles will run across the valley.

Open roof valley this is almost the same as the closed roof valley method except a pre bent metal valley lining is installed instead of a secondary roof underlayment. An open valley relies on metal flashing for protection. For an open valley a sheet of metal usually steel sometimes copper is fastened to the roof deck. Once the shingles are installed they don t run through the valley area.

First clean the debris out of the valley including sawdust nails and whatever else is in there. Shingle the other side of the valley the same way. The metal is usually pre painted to best complement the shingles color blend. Valleys are typically found where gable dormer roofs meet the main roof or when a house has angled wings or additions where two roof sections in different planes meet.

That flashing is left exposed so the roof has visible lines of metal running down the valley. Fold the top over the roof ridge and cut the bottom along the drip edge metal. Open valley shingle installation makes use of the metal flashing sheets that need to be installed so that they overlap each other by few inches with the upper piece of sheet is resting over the bottom piece. This allows water to fall from the higher slope to the lower slope and prevents it from going under the shingles to the roof deck.

During its installation process the open valley shingle utilizes the w metal flashing which helps in preventing the water from rushing down. This leaves a metal strip or line on the surface of the roof that serves as the valley line. Install synthetic roofing underlayment or felt paper according to manufacturer specifications and then install the first piece of valley flashing. The valley area of a roof the straight lines formed when two different planes of the roof meet is a critical area that handles a tremendous amount of water run off.

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.