Wood lasts a long time in Seattle, but it does not forgive water mistakes. Our climate sits in a narrow band between gentle drizzle and sideways rain, with marine air that keeps surfaces damp for days. That mix is perfect for fungi that turn solid framing into crumb cake. Over the past decade, I’ve inspected and repaired hundreds of homes that looked fine from the street and turned out to have rot threading through window trim, sheathing, and even structural members. The patterns repeat, and so do the lessons.
What follows are real-world case studies with the messes we found, the choices we made, and how we left each home stronger than we found it. If you’re comparing siding contractors in Seattle or trying to decide between spot fixes and full siding replacement services, you’ll see how we weigh cost, risk, and long-term performance. I’ll also call out details any dry rot repair contractor should be talking about during your inspection.
How dry rot really happens here
In Seattle, rot rarely starts with dramatic failures. It sneaks in at small breaks in the water management system: a missing kickout flashing where a roof meets a wall, a hairline gap in caulking above a window, a flat threshold on a deck door, or a piece of exterior trim capped with caulk so it can’t drain. Once water gets behind siding and stays trapped for more than a few wet cycles, wood moisture content climbs past 20 percent and fungus wakes up. Add poorly vented cavities and you get sustained moisture, which fungi love. Cedar and redwood resist better than spruce or hemlock, but any wood can rot if it stays wet.
The tipping point is often invisible from the outside. Paint can look perfect while sheathing behind it turns to mulch. That’s why a proper Seattle dry rot inspection means more than tapping with a screwdriver. We probe suspect areas, use moisture meters, and open representative sections. When a customer asks for “just a trim and siding repair around the window,” we explain that the visible rot is seldom the full story. Most of our case studies start with a small clue and end with a systemic fix.
Case study 1: Craftsman bungalow with “smile” cracks over windows
The home: A 1926 Craftsman in Ravenna with original cedar shingles, two coats of paint, and classic divided-light windows. From the street, it looked well kept. The owner called about repainting and minor exterior trim repair because hairline “smile” cracks kept reappearing above several windows.
What we found: The header trim had been caulked tight to the shingles with no head flashing. Water running down the shingles hit the caulk, backed up, and slipped behind the trim. The cracks telegraphed the movement of softening material below. Probing with an awl punched through the header trim in two spots. Moisture readings ranged 18 to 26 percent at the upper corners of three windows. We opened one section and found rotted 1x trim, damp felt paper, and sheathing with “punky” fibers. The old building paper had done all it could for a century, but without metal flashing at the tops of openings, it was overmatched.
What we did: The owner wanted to preserve the look and avoid ripping off the whole facade. We staged a targeted repair. We removed the window head and side casings on the three affected openings, plus two shingles above each head to access the flashing plane. We cut back the compromised sheathing to sound wood and replaced with 1/2-inch CDX. We integrated new flashing tape to the window flanges, added a bent head flashing that kicked past the trim, and layered new felt and shingles so water shingled over, not behind, the trim. We primed all cut ends and installed new clear vertical-grain fir trim to match the period profile, leaving a small, paintable gap above the head trim so the flashing could work. After paint, the change was invisible.
Before and after: The “smile” cracks did not return. More importantly, moisture readings at six and twelve months stayed below 12 percent. The homeowner kept the original windows and the shingle field intact, and the repair cost landed in the lower middle range for house trim repair, far under what a full tear-off would have run. The trade-off was calculated risk: we accepted that the rest of the facade was old but serviceable. We marked other locations to monitor and scheduled a follow-up Seattle dry rot inspection after the winter.
Key takeaways: Historic details can be saved with surgical work if you correct the water path. The critical addition was the unseen head flashing, not the paint or caulk.
Case study 2: Newer fiber-cement siding, big hidden problem
The home: A 2009 two-story in West Seattle with fiber-cement lap siding, vinyl windows, and simple trim. The owner noticed blistering paint on a single piece of vertical trim at a second-floor corner. They requested siding repair Seattle homeowners often ask for: “just replace the bad trim and repaint.”
What we found: Corner trims should be backflashed and left with a small gap at the top for drainage. This corner had neither. The contractor had run the housewrap to the corner, stapled the trim over it, and caulked every seam tight. The roof’s lower eave terminated against that wall without a kickout flashing, so roof water hammered the wall during storms. Moisture readings at the corner were 28 to 35 percent, high enough for active rot. We pulled three courses of lap siding adjacent to the corner and found blackened OSB sheathing. When OSB decays, it loses its flakes and becomes a furry mass. We traced staining down to the floor line and up to the eave.
Scope decision: This is where owners face a fork in the road. Option one, do a sectional repair: replace the corner trim, a few sheets of sheathing, and reinstall the siding with proper flashings. Option two, use this as the trigger for a larger siding replacement in that elevation, possibly the whole house. The deciding factors were the age of the siding, the absence of a rain screen, lack of kickouts at two roof-to-wall transitions, and the owner’s long-term plans. They planned to stay at least ten years and were already frustrated by peeling caulk lines.
What we did: We recommended a full elevation replacement on the affected side, not the entire home. We removed roughly 280 square feet of siding, exposed and removed compromised OSB between two studs bays wide and one story tall, and replaced with 1/2-inch CDX that tolerates incidental wetting better. We installed kickout flashings at both roof-wall intersections. Then we built a 3/8-inch rain screen gap using furring strips, rewrapped with drainable housewrap, and reinstalled new fiber-cement lap siding with proper clearances at grade and roofing. We rebuilt the corner with backflashed trim and left a capillary break at the top. We also caulked only where details call for it, not across drainage paths.
Before and after: From the street, you’d call it a color-matched patch, not a remodel. Behind the paint, the wall now dries quickly after rain, and the corner no longer soaks. Moisture readings dropped to 9 to 12 percent once the fall rains began, which is normal. The owner saved about 40 percent compared to full-house siding replacement services Seattle contractors often pitch for similar findings. We documented the work for future disclosure, a helpful detail if the home goes on the market.
Key takeaways: Fiber-cement is durable, but details around it make or break the assembly. Kickout flashings stop a surprising percentage of rot calls. If your home lacks them, expect trouble.
Case study 3: Back deck door with mushy threshold and hidden rim rot
The home: A 1980s split-level in Shoreline with a west-facing back deck. The sliding door threshold felt spongy, and ants were showing up along the baseboard in the family room. The owner suspected a door issue and asked for exterior trim repair around the opening.
What we found: The deck had been rebuilt twice over the years, each time tight to the house with ledger lag bolts through the siding and thin flashing stapled above the ledger. The sliding door sat too low, with the threshold nearly flush to the deck surface. Driving rain soaked the deck surface, ponded at the threshold, and bled water into the door pan area. The ledger flashing had small nail perforations and ended 8 inches shy of the door opening, inviting water to track behind. We opened the interior baseboard and found staining on the subfloor. From the exterior, we pulled three deck boards and discovered the rim joist behind the ledger was dark and soft across a four-foot span.
Decision points: You can cap a door, inject epoxy, or replace the unit. But with rim joist decay, you have to address structure. The owner wanted a durable fix without replacing the whole deck.
What we did: We supported the deck temporarily, removed the ledger at the affected section, and explored the rim joist. About half the joist depth was degraded. We cut back to sound wood and sistered in new pressure-treated members, tying into the next two joists to restore capacity. We demoed the sliding door and installed a new, higher-threshold unit with a proper pan flashing built from preformed flashing plus liquid-applied corners. We added a sloped sill extension that shed water over the deck, not into the wall. The ledger went back with through-bolts, stand-off spacers creating a rain gap, and a continuous, unperforated metal flashing that extended past the door edges with end dams. We also added a small diverter so water running off the wall could not track along the ledger.
Before and after: The ants left, moisture stabilized, and the room’s musty smell disappeared within a week. The new threshold sits a half inch above the deck surface with a sloped sill that sheds water. The deck feels the same underfoot, but the wall behind it now has a fighting chance. This repair cost more than a cosmetic house trim repair but far less than a deck rebuild. The owner learned a useful lesson: low thresholds and flat surfaces invite rot. If your deck design doesn’t add a drainage gap and sloped transitions, you’ll be calling a dry rot repair contractor eventually.
Key takeaways: Door pans and ledger details are workhorses in Seattle. Spend time on them, and you prevent a long chain of repairs.
Case study 4: Mid-century ranch with aluminum-capped trim
The home: A 1954 ranch in north Seattle that had been “maintenance free” retrofitted in the late 90s with aluminum coil stock over existing wood trim. The homeowners noticed wavy metal and minor bulges at corner boards but no obvious rot. They were interviewing siding contractors in Seattle for a potential update.
What we found: Metal capping keeps paint brushes away, but it also traps water if not ventilated. We removed one small piece at a window sill and found wet, blackened wood. The cap had been caulked tight at the top and sealed at the ends. Condensation and incidental rain behind the siding had nowhere to exit. We opened a corner and found the original corner board half gone. The sheathing behind was dry in some sections but dark near the lower corner. The housewrap was an older, non-drainable fabric. Inside corners had no backflashings.
Options: The owners wanted a modern look and lower maintenance. We discussed targeted trim swaps versus full siding replacement. Given the age of the assembly, lack of rain screen, and the number of windows with capping, they chose a full exterior refresh.
What we did: We removed all aluminum capping and the original bevel siding. We repaired sheathing in six small areas, each from 2 to 6 square feet. We replaced two corner boards and added a drainable wrap with vertical furring to create a 3/8-inch ventilation space. We installed fiber-cement lap siding with factory-primed cedar trim for warmth, and upgraded to prefinished materials to reduce site painting. Window heads received bent head flashings, and sills got slight drip kerfs beneath. At the eaves, we added kickouts at both roof-to-wall intersections. The crew carefully kept fasteners out of the flashing planes to avoid Swiss-cheesing the metal.
Before and after: The home shifted from tired aluminum to crisp lines with shadow reveals that make a mid-century facade sing. More important, the wall can now drain and dry. The owners won’t be chasing soft trim every few seasons, and Seattle trim repair should be off their to-do list for a long while.
Key takeaways: Metal capping is not a water management system. If you don’t provide a path for moisture to exit, it will find one through your wood.
Case study 5: Multifamily townhouse row with stucco panels
The buildings: A row of six attached townhomes in Ballard built in 2013 with a mix of fiber-cement and stucco-style panels. The HOA called for a Seattle dry rot inspection after seeing staining below balconies and a soft spot around one gas meter. The request came in as “siding repair Seattle” because they expected a few panel replacements.
What we found: The balcony ledger flashings were short and terminated behind trim without end dams. At two locations, stucco panels met horizontal trim with sealant only, no Z-flashing. Probes around the meters suggested elevated moisture. We opened two test sections at different homes and found familiar problems: wet OSB at horizontal trim lines, staining around meter penetrations, and a bit of fungus growth. The building had no rain screen and relied on sealants to keep water out. That works for a few years, then the sealant ages and water sneaks in.
Scope decision: HOAs need predictability, so we mapped all similar details and proposed a phased repair: correct the worst two elevations immediately and improve the rest over two seasons. We also encouraged the HOA to standardize details so any siding contractors Seattle WA might involve in the future would follow the same approach.
What we did: We replaced the rotten sections of sheathing, added Z-flashings at every horizontal break, used prefinished fiber-cement trim with back flashing, and installed end-dammed balcony flashings. We swapped a handful of stucco panels for new panels integrated with metal trims that allow drainage, and we added drainable wrap behind. We sealed penetrations with gaskets rather than relying on caulk alone. Then we re-established control joints in the panel system so expansion wouldn’t tear sealants away. The HOA opted not to do a full rain screen conversion across all walls, a cost and disruption decision, but we created tiny drainage channels wherever we opened the wall.
Before and after: Staining stopped, moisture readings dropped, and owners saw fewer hairline cracks in the stucco panels. The HOA spent less than a whole-building reclad while tackling the details most likely to cause recurrent rot. They scheduled follow-up inspections every two years, which is smart maintenance in our climate.
Key takeaways: In multifamily buildings, repeat details cause repeat failures. Fix the detail, not just the symptom at a single unit.
What a thorough Seattle dry rot inspection should include
A good inspection sets the repair up for success. If you bring in a dry rot repair contractor, ask about their methods. In our climate, a thorough assessment usually covers the following:
- Moisture mapping with a pin meter at likely failure points, including window heads, sills, inside and outside corners, deck-ledger interfaces, and roof-to-wall transitions. Targeted exploratory openings at representative problem areas instead of guessing from the surface. Verification of critical flashings: head flashings over windows and doors, Z-flashings at horizontal band boards, kickout flashings where roofs meet walls, and end dams at balcony and ledger terminations. Drainage and drying evaluation, including whether a rain screen exists, whether siding has proper clearance at grade and roofing, and whether trim detailing allows water to exit rather than trapping it. A written scope that explains assumptions, unknowns, and contingencies if hidden damage appears. This protects both owner and contractor when the first piece of siding comes off.
This is the one list we’ll keep short and useful. If your inspection lacks these elements, you’re guessing.
Choosing between spot repairs and larger scopes
There is no single correct answer every time. I’ve replaced one rotted sill on a 100-year-old house and left the rest of the wall alone because everything else was dry and the water path was corrected. I’ve also recommended full elevation replacements when three factors lined up: multiple water-entry sources, no rain screen, and significant sheathing decay.
Here’s how we think about it. First, find where water is getting in and fix that path. If you cannot correct the water path without opening a larger area, a spot repair will not last. Second, sample enough locations to understand whether you have isolated pockets or a systemic detail failure. Third, consider the age of the cladding and your timeframe in the home. If you plan to stay for a decade and the cladding is near end of life, siding replacement services Seattle WA https://www.seattletrimrepair.com/service-areas/redmond/ homeowners often invest in may be the better long-term value. If you plan to sell in a year and the damage is isolated, a targeted repair with solid documentation can be appropriate.
We also look at the cascading effect of each choice. A small fix might cost less today but lead to repainting sooner, mismatched textures, and repeated mobilizations. A larger scope spreads staging and setup costs across more work, which can be efficient. The difference often hinges on how many high-risk details you can address in one go.
Materials and details that endure in Seattle
When we rebuild, we lean on a few materials and practices that consistently outperform the rest in our conditions. Pressure-treated framing where required by code, CDX plywood over OSB in wet-risk areas, vertical-grain fir or high-quality primed wood for exposed trim, and fiber-cement siding for balanced durability and cost. For windows and doors, pan flashings matter as much as the unit. We use preformed pans or carefully built liquid-applied pans that slope to daylight. All cut wood gets primer or end-grain sealer before installation. We keep siding at least 6 inches above soil and 1 to 2 inches above roof surfaces, even if it means pushing back on aesthetics.
Ventilation behind the siding is the workhorse in our marine climate. A simple rain screen gap, even 3/8 inch, changes the physics. Walls dry faster and sealants last longer because the assembly isn’t constantly damp. That single choice reduces future calls for seattle trim repair and house trim repair across the board.
We also avoid the seductive overuse of caulk. Caulk belongs where two materials must be sealed, not across horizontal laps or as a substitute for flashing. If a detail depends on sealant alone to shed water, it will eventually fail.
Cost ranges and what drives them
Costs vary widely, but patterns emerge. A straightforward exterior trim repair around a single window might land in the lower four figures, assuming limited sheathing damage. Add sheathing replacement and head flashing work and you can double that. Sectional siding repair on a single elevation might run into the mid four figures or more, depending on access, material choice, and paint scope. A full elevation replacement with rain screen, flashing upgrades, and paint often pushes into five figures. Full-house reclads scale from there.
What drives numbers up are access challenges, rot in structural members, paint color matching that forces whole-wall repaints, and scope creep triggered by hidden conditions. What keeps costs contained is a precise scope, a contractor who explains contingencies, and decisions that solve more than one problem at a time, like adding kickouts while the wall is open.
If you solicit bids from siding contractors in Seattle, compare more than the bottom line. Look at whether they specify rain screens, real head flashings, and kickouts. Ask how they handle unexpected findings. A cheap number that plans to caulk and paint over a problem is no bargain.
Maintenance that prevents the next repair
After repairs, small habits protect your investment. Keep vegetation off walls so surfaces can dry. Clean gutters and verify downspouts discharge away from the foundation. Inspect caulk at critical flashings annually and touch up paint at cut ends before the wet season. Watch for recurring “tells” like peeling paint at lower corners, swollen trim, or ants near thresholds. When you replace a roof, insist on proper kickout flashings at roof-to-wall intersections. When you add a deck, keep the ledger off the wall and the door threshold above the deck surface.
These steps are modest but powerful. Seattle’s climate rewards assemblies that drain and breathe. It punishes those that trap water.
When to call for help, and what to ask
If a screwdriver sinks into your trim, if you see bubbling paint around window heads, if a deck door feels soft underfoot, or if your nose picks up that earthy, sweet smell in one corner of a room, it’s time to talk to a pro. When you call a dry rot repair contractor, ask for a real inspection, not a drive-by quote. Ask what the water entry path is and how the repair will interrupt it. Ask whether they will open representative areas, how they will integrate flashing with the existing wrap, and whether they recommend a rain screen. If they suggest caulking as the primary solution, keep shopping.
Homeowners sometimes frame this as “trim and siding repair” because that’s what they see. The best contractors see layers: cladding, drainage plane, flashing, sheathing, structure. You want someone who can touch each layer as needed, not just the surface.
A note on timing and weather
Seattle gives us small windows to work. Dry rot repair Seattle projects move faster and cleaner in late spring through early fall. We can work in light rain with proper protection, but we need dry surfaces to apply tapes and coatings. If you schedule work in November, build in weather delays and budget for more tenting and heat. For small urgent openings, we stabilize and return when conditions cooperate.
Even in winter, inspections make sense. You may get truer moisture readings, and active leaks are easier to spot. We sometimes stage emergency flashing patches to buy time, then return for permanent repairs.
Final thoughts from the field
I have pulled off immaculate-looking trim to find sponges where wood should be, and I have opened ugly, peeling paint only to discover perfectly dry sheathing behind it. Surface appearance misleads. Water management details tell the truth. The best outcomes come when owners and contractors slow down at the beginning, learn how the assembly got wet, and then fix the system so it can dry.
Seattle homes are worth that care. With the right details — kickouts, head flashings, rain screens, drained sills, and sensible clearances — trim and siding last far longer. Repairs become rarer. And when you do need siding repair Seattle residents trust, you’ll know which questions matter and which choices will carry you through our long, wet months.
Seattle Trim Repair 8338 20th Ave NW, Seattle, WA 98117 (425) 517-1751