Another true confession, while I carried plenty of roof shingle bundles up ladders and onto roofs when I was young and dumb – I have never installed any other than cedar. One of our clients was requesting a “how to”, so downing my best sleuthing clothes, it was learning time for me. This article took a fair amount of research, however was fairly interesting and entertaining.
In my humble opinion, a steel roof is a better design solution due to installation ease and freedom from maintenance.
Closed-cut valleys, also called closed valleys, are installed quickly and have a cleaner, sharper look than woven valleys. From the ground, it looks as though shingles meet in a clean line in valley center. In reality, one shingle layer actually crosses the valley beneath another.
In summary, during closed-cut valley installation, first install roof plane’s shingles into the valley. It is essential to only use whole (not cut) shingles during this step. As roof shingles are installed upon the second roof plane, allow them to lap over the valley on top of the first shingles. Shingles on second layer are then cut, ideally creating a clean line down the valley center. A chalk line can be used to guide as shingles are cut.
Unlike a woven valley, a closed valley will not have hollows. However, closed valleys still rely on shingles to protect the valley, having drawbacks. Valley shingles may lose their granules, and thus their coloration and protective capability, faster than other roof portions.
Here is a short how to video: https://www.youtube.com/watch?v=TzWqSQ3G1gs
California valley is one closed-cut valley variation. For this method, last shingles on “cut” side of a cut valley are actually installed sideways, so they run up and down the valley. This saves shingle cutting time and is the fastest way to shingle a roof valley, but it does not provide adequate protection in most climates. Indeed, California valleys are prohibited in some areas. Always be sure to refer to local codes to see if they demand a particular valley installation type.