Granule loss
When the protective mineral coating wears off asphalt shingles, signaling age.
Asphalt shingles are coated with tiny mineral granules that block UV rays and protect the asphalt underneath. As a roof ages, those granules wear off — you'll see dark, bald patches on the shingles and a coffee-ground-like grit collecting in your gutters and at the bottom of downspouts. A little granule loss is normal, especially on a new roof, but a steady, growing amount means the shingles are aging and losing their sun protection, which accelerates the rest of their decline. Granules in the gutter are one of the clearest ground-level signs your roof is nearing the end of its life — see [how to maintain your roof from the ground](/guides/how-to-maintain-your-roof-without-getting-on-it).