What indicates that a roof is nearing the end of its useful life?

Extensive curling or buckling of the shingles is a critical indicator that a roof is nearing the end of its useful life. This physical deterioration suggests that the shingles are losing their structural integrity, which can lead to leaks and further damage to the underlying roof structure. Curling indicates that the shingles are separating from the roof surface, which happens due to prolonged exposure to elements, improper installation, or age.

In contrast, faded color or minor discoloration may be cosmetic issues and do not necessarily signify that the roof is failing. Loose gutters can affect water drainage and are a maintenance issue rather than an indication of the roof's overall condition. Therefore, extensive curling or buckling directly reflects the advanced wear and tear of the roofing material, making it the most telling sign of a roof nearing its end of life.