How to Trim Roof Shingles
- 1). Place the shingle where you would like it to go. Notice where and how much it overlaps the neighboring roof features you would like to trim around to give yourself a general idea as to where the trim should occur on the shingle.
- 2). Measure the width and height of the area you would like the shingle to cover. Use a carpenter's square or protractor to determine the angle of any cut that will not be 90 degrees.
- 3). Score the backside (the side with tar) of the shingle with a razor blade at the positions and angles determined in step 2. Score the tar to the mineral, or front, surface but not all the way through the mineral surface.
- 4). Hold the shingle in your hands on either side of the score, and evenly bend the shingle to snap it into two pieces.
- 5). Repeat steps 3 and 4 if multiple trims are required.
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