2-Minute Read
06/08/2023
Expert Insight
Why Dry Rot Is a Major Risk in the Pacific Northwest
Living in the Pacific Northwest comes with plenty of perks—lush landscapes, fresh air, and mild seasons. But our wet climate also creates the perfect storm for a hidden homeowner menace: dry rot. According to climate data, cities like Portland and Seattle average over 150 days of rain per year. That moisture seeps into siding, trim, and framing—especially in homes built before modern waterproofing standards.
Dry rot is a fungus that silently destroys wood by feeding on its cellulose, and it thrives in damp, poorly ventilated spaces. Left unchecked, dry rot can quietly eat away at your home’s structural integrity, causing serious (and expensive) damage that isn’t always covered by insurance. Recognizing the signs of dry rot in your home early can save you from major repairs.
Here at SFW Construction, we’ve seen it all. With over two decades of experience repairing siding, framing, and trim compromised by moisture, we know exactly what to look for—and what to fix before it spreads. If you own a home in Portland, Seattle, or anywhere in between, here are five signs of dry rot in your home that might already be working their way through your walls.
1. Soft of Spongy Wood Near Windows and Doors
Give your window trim or door frames a gentle push. Do they feel soft, spongy, or even crumble a bit under pressure? That’s a red flag. Moisture can seep in through tiny cracks, slowly feeding fungi that break down the wood fibers from the inside out. These are classic signs of dry rot in your home.
Why this matters: Once the wood loses its structural integrity, it can no longer hold nails, seal out moisture, or support weight. Soft wood in key structural areas like sills or headers could mean deeper internal rot.
What not to do: Don’t just repaint or re-caulk over soft spots—this can trap moisture and make things worse. Always investigate further.
2. Peeling Paint or Cracked Caulking
Paint protects your siding, but when it starts to bubble, peel, or flake, it’s often a symptom of trapped moisture. Likewise, cracked or missing caulking around joints and seams is an invitation for rain to sneak in and create the perfect environment for rot.
Why this matters: In our rainy climate, even a hairline crack can allow enough water inside to kickstart rot. Over time, those tiny leaks cause significant damage.
What not to do: Avoid doing patch paint jobs without identifying the underlying cause. If the paint is failing repeatedly in the same area, it’s likely a deeper issue.
3. Musty Odors or Recurring Mold Inside
Dry rot often starts where you can’t see it—behind walls, under siding, or around window frames. But you might smell it. A persistent musty odor or recurring indoor mold near exterior walls could mean there’s wood decay happening just out of sight.
Why this matters: Musty smells and mold aren’t just aesthetic problems—they signal persistent moisture that could lead to or already indicate wood rot. If mold keeps returning even after cleaning, it’s time for a professional inspection.
4. Visible Fungal Growth or Mushroom-like Blobs
It sounds dramatic, but it happens. In advanced cases, dry rot can lead to visible fungal growth on wood surfaces. If you see unusual discoloration, stringy textures, or mushroom-like structures, don’t wait—call a professional right away.
Why this matters: This means the fungus has matured and is releasing spores—potentially spreading the decay across your home’s structure.
What not to do: Avoid removing fungal growths without protective gear. You could spread spores or make exposure worse.
5. Warped or Sagging Siding and Trim
If your siding looks uneven or sections of trim seem to be pulling away from the house, that could be rot weakening the structural materials underneath. It may start small, but it doesn’t stay that way.
Why this matters: Once wood loses its rigidity, it can warp or collapse, impacting both the exterior look and the weatherproofing of your home.
What not to do: Don’t nail warped siding back into place without checking underneath. You might be covering up the real issue.
How Dry Rot Starts: A Quick Guide
Dry rot fungi need four things to thrive: wood, oxygen, warmth, and moisture. That last ingredient is why homes in the PNW are at particular risk. Once spores land on damp wood, they germinate and send out thin strands (hyphae) that break down cellulose. This process can travel through plaster and masonry, meaning the rot can move well beyond the original leak site.
Older homes without modern flashing or weather barriers are even more vulnerable. Leaky gutters, poor drainage, and unsealed joints are common contributors we encounter.
Why Acting Fast Saves Time and Money
The longer dry rot goes untreated, the more extensive (and expensive) the repairs. In early stages, spot repairs and targeted treatment may be enough. Left alone, it can mean tearing out large sections of siding, sheathing, or even structural framing.
Typical dry rot repair costs:
- Minor repairs: $1500 – $3000 (patch and treat)
- Moderate damage: $3500 –$7500 (section replacement)
- Severe cases: $7,500+ (structural rebuilds)
And don’t forget—dry rot can affect home resale value, and many buyers request full remediation before closing.
Know the Signs of Dry Rot in Your Home
- Inspect key areas monthly: especially near windows, doors, decks, and anywhere wood meets masonry.
- Maintain gutters and downspouts to prevent water pooling near your foundation.
- Use a screwdriver to test wood firmness in suspect areas.
- Document signs (photos, notes) in case you need to file a repair claim or consult a pro.
Still unsure? That’s where we come in.
Recognizing the signs of dry rot in your home early is key to minimizing cost and disruption. The sooner you act, the easier it is to isolate and fix the damage.
Why Homeowners Trust SFW Construction to Repair Dry Rot
With nearly two decades of experience, SFW Construction is the Pacific Northwest’s go-to expert for dry rot repair. We’re certified in James Hardie siding installation, DuPont Tyvek weather barriers, and lead-safe practices—so you know the job is done right and done safely.
Our teams are local, responsive, and specialize in the unique moisture challenges of homes in Portland, Seattle, Eugene, Bend, and along the Oregon Coast.
Frequently Asked Questions: Dry Rot
It is very difficult to estimate how long dry rot repairs might take. Minor cases can be completed in 1-2 days. More extensive rot or structural damage may require 3-5 days depending on the severity of the damage.
Don’t Wait Until It’s Too Late to Repair Dry Rot
Dry rot repair is far more affordable (and far less invasive) when caught early. If you notice any of these signs, schedule a free inspection with SFW Construction. Our licensed, lead-safe certified crews serve homeowners across Oregon and Washington, with specialized experience in high-moisture environments.
Protect your biggest investment. Schedule your free estimate today →