What’s Wrong with this Picture?
The “zipper” pattern is caused by installing the shingles using the vertical racking method. When shingles are installed using this faster but substandard method, the shingle seal can be damaged. This practice prevents the shingles from properly adhering to the roof. The vertical installation creates an expansion joint at the ends of the shingles. ThroughRead more about What’s Wrong with this Picture?[…]