Half the Oregon roofs we are asked to replace do not need replacing yet. The other half should have been replaced two winters ago. The job of an honest roofer is to tell you which one you have — and to be willing to walk away from a sale to do it. After seventeen years of climbing Oregon roofs, here is the framework we actually use.
The five factors that decide it
Roof replacement in the Pacific Northwest is not a single judgement call. It is the intersection of five questions, in this order: age, deck condition, shingle integrity, flashing and penetration health, and the cost of repair versus a fresh system. Skip any of these and the answer you get is somebody's quota, not your reality.
When we run a Storm Ready Inspection — that is the free roof and exterior check we offer to any homeowner in our service area — we walk through this list out loud, take photos at every step, and leave you with a written summary. If your roof has another decade in it, we will tell you. If it does not, we will tell you that too, and we will give you a number.
Factor 1: Age, but adjusted for installation quality
The shingle manufacturer's printed lifespan is a laboratory number. In the Willamette Valley, the variables that actually matter are attic ventilation, underlayment type, and whether the original installer used proper starter strips at eaves and rakes. A correctly built architectural shingle roof should last 22 to 28 years in our climate. A roof installed by the lowest bidder in 2008 with no soffit-to-ridge ventilation is often spent by year 16.
We have torn off roofs that were technically "20 years old" but had been dead for five of those. We have also looked at 30-year-old roofs that still had usable life because somebody did the original install right. Age is a clue. It is not a verdict.
Factor 2: The deck under the shingles
A roof system is shingles, underlayment, flashing, ventilation, and a wooden deck. The deck is the part you cannot see from the ground, and it is the part that decides whether a repair is even worth attempting. If the OSB or plywood is rotted, soft, or delaminating, we have to tear off to find out how much, and at that point a repair has already turned into a partial replacement.
Signs that the deck has failed: visible sagging between rafters, soft spots underfoot when we walk it, staining on the underside of the sheathing visible from the attic, and moss colonies that have lifted shingles enough to expose nail heads. Any one of those moves the conversation from repair to replacement.
Factor 3: Shingle integrity across the whole field
A few missing shingles after a windstorm is a repair. A field of shingles that have lost their granules, curled at the edges, or cracked across the tabs is a replacement waiting to happen. The test we run on every inspection: pick three shingles from three different exposures (south, west, north). If two of the three are brittle, granule-stripped, or cup-shaped, the roof is past the point where patching is honest work.
Factor 4: Flashing, valleys, and penetrations
Most leaks in Oregon homes are not shingle failures. They are flashing failures — at chimneys, valleys, wall step-flashing, plumbing boots, skylights, and dormers. If your roof is in otherwise good shape and you have one persistent leak, the answer is almost always a flashing repair. We have stopped twenty-year leaks with a $900 chimney re-flash on roofs that had eight more years of service left.
"If your roof has another decade in it, we will tell you. We would rather sell you the right $1,800 repair than the wrong $25,000 replacement."
— Gabriel Horta Blancas, Owner
Factor 5: The math, told straight
Once we know what is happening on your roof, the decision usually comes down to a ratio. If a repair will cost more than 30 percent of a full replacement and the roof has fewer than seven years of remaining life, replacement is the smarter spend. If the repair is under 15 percent of replacement cost and the roof has ten or more years left, fix what is broken and leave the rest alone.
Quick reference: repair vs replace
| Condition | Repair | Replace |
|---|---|---|
| Roof age | Under 70% of expected life | Past 80% of expected life |
| Deck condition | Solid sheathing, no rot | Soft spots, visible rot, sagging |
| Shingle field | Granules intact, isolated damage | Widespread curling, balding, cracking |
| Leak source | Single flashing or boot | Multiple unrelated leak points |
| Repair cost vs full replace | Under 15% | Over 30% with under 7 years left |
What you should not do
Do not let any contractor recommend a full replacement without showing you photos from on the roof. Do not accept an overlay (a second layer of shingles on top of the old roof) — it is legal in Oregon, it voids most manufacturer warranties, and it traps moisture against your sheathing. Do not sign anything the same day a storm-chasing crew knocks on your door. And do not chase the cheapest bid; the labor that fails fastest is the labor that was priced to win.
How we run our inspections
Every roof we inspect gets the same five-step pass: ground assessment, on-roof condition walk, attic check, flashing and penetration audit, and a written report with photos. We show up Monday through Saturday, 8 AM to 7 PM. The inspection is free. The recommendation is honest. If we say repair, we mean repair. If we say replace, we will show you exactly why.