The answer to 'why is my downspouts curling shingles' is that improper downspout placement or drainage can cause water to pool near the roof's edge, leading to premature shingle curling or damage. This happens when downspouts direct water too close to the home's foundation or don't allow it to flow away properly.
The pooling water can saturate the shingles, causing them to curl up at the edges. This creates gaps that allow more water to seep under the shingles, leading to leaks, mold, and further damage over time. Fixing this issue often requires adjusting the downspout position or adding extensions to direct water farther from the home.