Shingles may delaminate and slide. This is caused by improper fastening. Shingles are designed to be nailed in a specific area, increasing wind resistance and ensuring that both parts of the shingle are attached to the roof. Today’s shingles are constructed in two parts. The “base” and the “dragon tooth” overlay. When fasteners do not penetrate both parts of the shingle the base can come apart, especially on high pitch roofs.