The answer to 'why is my flat roof curling shingles' is that curling shingles on a flat roof are often caused by improper installation, moisture buildup, or aging materials. Flat roofs are more susceptible to shingle curling due to the lack of a steep slope to shed water. Common symptoms include shingles lifting at the edges or center, cracks or splits in the shingles, and a wavy or uneven roof surface.
The most common causes are poor installation where the shingles were not properly secured, exposure to excessive moisture from leaks or pooling water, and normal wear and tear over time as the shingles deteriorate. Curling shingles can lead to further roof damage and leaks if not addressed. For minor curling, a DIY repair may be possible, but significant issues likely require a professional roofing contractor to assess the roof and make the necessary repairs or replacement.