Closed Valley Roof
Ultimately laying any shingle in a valley can restrict proper water and debris flow unlike the metal flashing used in an open valley.
Closed valley roof. The open valley looks like each plane of the roof was cut in separate and the eye is drawn to the separation. For a closed valley shingles are installed across the joint where planes intersect. 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. When finished the valley and its underlayment will be completely covered with asphalt shingles.
Before the installation of a shingle roof assembly the roofing contractor installs an underlayment over the entire roof deck. Closed cut valleys are notorious for their ugly looks. With each new course roofing shingles continue up the valley. Indeed the overlapping shingles make the roof look very unsightly.
The self adhering section acts as the lining for the valley. The closed variation is a flashing that has been completely covered with shingles while in the open variation will have the flashing completely exposed to the elements. If you have a shingled roof as most torontonians with a sloped roof tend to have then you will have one of two kinds of valleys on your home. Further they wear out faster than a metal valley.
If you are installing a closed valley the roofer will install shingles to the roof deck and extend the shingles through the valley so that it covers the entire valley area. California cut valleys make for a great closed cut valley however we have an installation trick to improve performance in areas of high winds snow or rain. These disadvantages are neutralized by their simplicity of installation. Incorporated into the underlayment may be a self adhering ice and water shield or another type of underlayment that is a heavier gauge than the underlayment that covers the remainder of the.
This might lead to annoying leaks in heavy rains or at the very least a damaged roof underlayment. One variant of the closed cut valley is the california valley also called long island valley and new jersey valley. This roof is on a small cabin in the back of beyond and the only valleys will be on 3 small dormers with about 6 feet of valley per side so i m not sure the water will wear out the valley shingles argument will work. What is a closed valley roof.
Pros and cons of a closed valley roof architects often prefer closed valleys to open valleys as they feel that it gives a home better architectural appeal.