Roof Rot Repair Across the Willamette Valley
Rotted sheathing, decking, fascia, and rafter repair — plus the flashing and ventilation fixes that stop the moisture from coming back.
Why Oregon Roofs Rot — and How We Fix It
Rain or Shine Roofing provides roof rot repair for homeowners and businesses across the Willamette Valley and Oregon Coast — decking, sheathing, fascia, soffits, and rafter work. Oregon’s 40+ inches of annual rainfall (and 70+ inches on the coast), year-round humidity, and long wet winters make rot a near-constant threat to any roof that isn’t ventilated, flashed, and drained correctly. Targeted rot repair typically runs $500 to $3,500, depending on how much wood needs replacement and whether the moisture source also needs correction.
What does “fixing the source” mean?
Cutting out rotted wood and nailing in new sheathing only delays the problem if the original cause is still there. We trace moisture back to its source — failed step flashing, blocked drainage, inadequate ventilation, or an ice dam pattern — and fix that first. Otherwise the new wood rots within a few years and you’re paying for the same repair twice.
Where Rot Shows Up First
Rot doesn’t usually start where you can see it. By the time a homeowner notices a sagging fascia board or a soft spot when they walk the roof, moisture has been working for years in places you can’t easily inspect.
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Eaves and Fascia
Ice dams and blocked drainage push water under the drip edge. Fascia boards and the first row of sheathing take the damage.
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Valleys and Wall Intersections
Concentrated water flow plus any flashing imperfection equals rot. Valleys are the single most common rot location on Oregon roofs.
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Around Chimneys and Skylights
Counter flashing and step flashing are tricky details. When they fail, water runs down into the rafters and rots framing members.
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Under Moss-Covered Areas
Moss holds moisture against shingles 24/7. Granules break down, shingles curl, water gets to the underlayment, and the decking rots silently underneath.
Examples From Recent Willamette Valley Jobs
Every one of these roofs looked fine from the ground — until we pulled the shingles back and found what was underneath.
How Roof Rot Repair Works
Four steps from inspection to finished fix.
Inspection & Source
Locate the rot, trace the moisture source, and document with photos. No guesswork — we show you the damage.
Cut Back to Solid Wood
Remove damaged sheathing, fascia, rafters, or soffit. Cut back until every piece of remaining wood is sound and dry.
Replace & Waterproof
New framing and ½″ CDX plywood sheathing installed, then proper ice and water shield, flashing, and underlayment before roofing goes back on.
Fix the Root Cause
Correct the ventilation, flashing, or drainage issue that caused the rot — so the repair actually lasts.
Roof Rot FAQs
What causes roof rot in Oregon?
How much does roof rot repair cost?
Can roof rot be repaired without replacing the whole roof?
Last Updated: May 2026
Spotted Soft Decking or a Sagging Fascia?
Call today and a professional roofer will get back to you right away — free rot inspection, moisture source traced, and a detailed written proposal for a targeted repair. No pressure, no upsell.
(541) 606-3306