The shingles are woven together from either side of the valley. The advantage of a woven valley is that it does not leave an exposed flashing, which results in a cleaner look. The downfall is that leaves and twigs don’t get washed away as simply, which can trigger little water dams. This is very true for roofs with low pitches.
Use a tin snips to cut the drip edge to dimension. Make positive this row has a slight overhang (1/4 to three/8 in.) past the drip edge. The starter course protects the roof by filling in the spaces beneath the cutouts and joints of the next row of shingles.
The adhesive on the starter course seals the tabs of the primary full course. Install the top ridge cap so the prevailing winds blow over the overlaps rather than into them. If wind is not a difficulty, begin at both aspect, or begin at each side and finish in the center. Rip the highest half off the final ridge cap shingle, and nail through the face of it with two nails on the ends of every side. Weave the step flashing and the roof shingles together so that water can’t get underneath the shingles.
If the overhang is greater than a foot, minimize some off and use the rest elsewhere. Another means of dealing with valleys is to make use of the “weave” method, which we don’t cover on this story.
Pay careful consideration to the corner particulars. Install your subsequent … Read More