How to Trim Shingles in a Roofing Valley
- 1). Center one shingle lengthwise in the valley.
- 2). Press the shingle into the valley, causing it to fold along the angle of the roof's valley.
- 3). Hold the metal ruler across the shingle's crease
- 4). Cut the shingle along the crease using the carpenter's razor.
- 5). Mark the left half "L" and the right half "R" using the chalk. These two shingle portions will serve as templates for shingles that you need to trim.
- 6). Place the cut shingle templates over the top of any shingle requiring trimming.
- 7). Cut the shingles needing trimming with the carpenter's razor, using the template as a straight edge.
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