Should I repair my roof or just replace it?
A decision framework for Eugene homeowners weighing repair vs replacement, with the 30% rule, the math on continued patching, and when each call makes sense.
The 30% rule (and where it breaks down)
The general industry threshold is 30 percent of the total roof surface. If damage affects less than 30 percent and the surrounding shingles are in good condition with 8-plus years of remaining life, targeted repair is the better financial call. Above 30 percent, or if the surrounding roof is showing systemic deterioration, replacement delivers better value than patching. The rule breaks down in Eugene because of moss: a roof that looks 20 percent damaged from the ground might be 60 percent compromised once moss is removed and the underlying shingles inspected.
What repair makes sense for
Three scenarios clearly favor repair over replacement. First, a discrete recent event, a wind-lifted shingle, a fallen branch, a hail strike, on an otherwise sound 5-15 year-old roof. The damage is bounded and the rest of the roof has years of life left. Second, a known specific failure point, deteriorated flashing at a chimney or skylight, valley flashing nearing end of life, a cracked pipe boot, on a roof in the 8-15 year age window. Targeted repair restores the failed component without touching the sound roof. Third, an insurance claim where the carrier is paying repair cost and the damage is bounded.
What replacement makes sense for
Replacement wins when the math of continued patching gets worse than starting fresh. Four signals: roof age 20-plus years and visible widespread deterioration; multiple leaks in different locations during a single wet season; granule loss across multiple slopes (not just one); and any sign of structural deck issues (sagging, soft spots in the attic). At year 22 on an asphalt roof in canopied Eugene, even successful repair just pushes the inevitable replacement out a year or two, and during that interval the deck is taking moisture damage that adds cost to the eventual replacement.
The cost math
A typical Eugene flashing repair runs $400-$1,200. Shingle replacement in one bounded area runs $250-$800. Across a 22-year roof life, two or three repairs at those numbers is reasonable maintenance. The trap is when repairs start stacking: $400 in year 16, $700 in year 18, $900 in year 20, $1,200 in year 21. At $3,200 in cumulative repair over five years, you've spent a quarter of a replacement budget on a roof that's still going to need replacement at year 22-23 anyway. That's the point where replacement becomes the better economic call.
Ask the contractor to walk you through both options
A trustworthy Eugene contractor gives you the honest read on both paths with the reasoning. Be skeptical of any contractor whose first response is 'you need a full replacement' without showing you the deck condition, the shingle condition, and the specific failure points. Be equally skeptical of any contractor who promises endless cheap repairs without addressing the underlying roof age. The right answer is usually obvious once both options are documented in writing, the wrong contractors talk you into whichever job they prefer to sell.