Roofing Valley Closed Cut

I think i first learned of the system reading a bundle of tamko shingles about 22 years ago and have used it frequently since.

Roofing valley closed cut.

In general the closed cut valley method implies stretching one side of the shingles beyond the valley while those on the other side are trimmed. If you are looking to install shingles you might want to consider the closed cut valley method. When it comes to your closed valley design there are a few options. Closed valleys may have a tendency if not constructed properly to channel water under the shingles laid over the bottom layer of shingles.

With each new course roofing shingles continue up the valley. It is essential to only use whole not cut shingles during this step. I begin the second side the side that will be cut by snapping a cutline 2 in. According to long time iko sales representative jeff tessaro closed valleys for residential construction have been popular since he was a roofing contractor in the late 90 s.

In summary during the installation of a closed cut valley you install the first roof plane s shingles into the valley. However open valleys may be susceptible to water back up along the top of the cut off shingles in the valley if not properly trimmed potentially causing roof leaks. For a closed valley shingles are installed across the joint where planes intersect. 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.

With a closed cut valley there s no need to shingle the two roof planes at the same time. In that case it wouldn t be a truly no cut valley but it would be faster than diagonally cutting each shingle. It is popular because the two roof planes do not need to be shingled at the same time. Shingles are overlapped across the valley on alternative slopes.

Tamko is the only shingle manufacturer that shows the no cut shingle valley process in their installation instructions. Plus cutting the closed cut valley shingles can happen after the rest of the roof is shingled. As you install roof shingles on the second roof plane you allow them to lap over the valley on top of the first shingles.