Open Cut Valley Roofing

When to choose a closed valley over an open valley.

Open cut valley roofing.

A basic demonstration for roofing contractors and homeowners on how to install gaf timberline shingles using the closed cut valley method. Jb wholesale roofing and building supply has 8 locations to serve everything you need for your roof whether residential or commercial. The metal is usually pre painted to best complement the shingles color blend. I m leaning towards an open metal valley but i ve had contractors disagree saying that the metal expands.

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 underlayment sheet metal liner if required and initial shingle covering into or through the valley follow the same guidelines for the standard closed cut valley and open valley construction. 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. Fold the top over the roof ridge and cut the bottom along the drip edge metal.

If homeowners are looking to have their roof last for many years an open valley is iko s recommended choice and a good up sell opportunity for the roofing professional. Open valleys may be susceptible to water backup if the cut off shingles are not properly trimmed potentially causing roof leaks. The shingles are then cut out of the valley area opening the surface of the valley lining to water run off and the environment. As another benefit to the roofing professional open valleys are sometimes used to easily bridge the gap between roof faces of vastly different pitches.

For a closed cut valley the installer should snap a chalk line 2 inches from the center line on the cut side. With a clean valley you can lay down some peel and stick roofing membrane. Roofing shingles are installed then cut and sealed where they overlap the metal channel. The closed cut valleys are cheaper and commonly done in my area but they tend to wear out sooner due to the high volume of water in the valley washing away the protective grit on the shingles there before on the rest of the roof.

Open 6 30 am to 4 30 pm mon fri check branch locations below for sat hours. For an open valley the installer should snap two chalk lines defining the cut edges of the valley on either side of the center line. With an open valley a strip of metal will be visible on the roof wherever two opposing roof planes meet.