The answer to 'architectural shingles sagging' is that sagging shingles are typically caused by improper installation, underlying structural issues, or aging roofing materials. Symptoms include a wavy or uneven appearance on the roof surface, and the shingles may start to pull away from the roof deck. Solutions can range from repairing or replacing the affected shingles to addressing more significant structural problems.
Homeowners should first inspect the roof to identify the root cause. Minor sagging from improper installation may be a DIY fix, but significant sagging or structural issues require a professional roofing contractor to properly diagnose and repair the problem.