A new roof may cost up to 10% of the value of a house, but delaying repair or replacement even by a year or two can put the entire structure at risk. Obvious signs that a roof needs work include missing shingles, slates, or tiles, damaged or missing flashing, and of course, signs of water penetration inside the house. Don’t overlook secondary roofs over additions, porches, and entries—they’re often the most vulnerable. Another indicator that the roof is nearing the end of its useful life is age, which varies by roofing material.
Asphalt & Fiberglass
Most asphalt roofs have a lifespan of 20 to 40 years. Fiberglass shingles last significantly longer, up to 50 years. Warning signs that the roof needs significant repair or replacement include: • missing or loose shingles • curling, cracked, dry or
blistered shingles • exposed or loose nail heads • dark patches (moisture penetra
tion, moss, falling granules) • water damage inside
the house or attic • missing or damaged flashing • a sagging roof line
Even in the absence of warning signs, if heating and cooling bills have gotten noticeably higher, the roof may lack sufficient ventilation have invisible damage. The best solution for a failing asphalt or fiberglass roof is to replace it. Take off every roof layer before reroofing, leaving the existing deck clean and free of nails before the new roof goes on.
Wood Shingles or Shakes
Whether hand-split or machine-cut, wood shingle roofs can last up to 60 years—but 15 to 30 is more common for modern, premium wood shingles. Longevity depends on the quality of the shingles and proper installation. (See “Roof Prep: Secrets to