When you live and work in Seattle, wood rot is not an abstract concept. It shows up as spongy trim at a hose bib, paint that bubbles at the bottom of a corner, a carpenter ant trail under a leaky gutter. I have rebuilt enough rot-damaged corner boards on Craftsman bungalows in Ballard and contemporary townhomes in West Seattle to know what causes it, how to stop it, and where people waste money trying to fix the wrong thing. If your house needs trim and siding repair, start with the corners. They are the canaries in the coal mine, the first place water reveals a problem with the building’s armor.
Why Seattle’s corners rot first
Our rain is persistent rather than dramatic. It falls at an angle for months, rides wind across wall faces, and wicks into tiny gaps where two surfaces meet. A corner board is three vulnerabilities meeting at once: an outside miter, an end grain at the bottom, and the interface with two siding runs. Add a clogged downspout that overflows, a missing kick-out flashing at a roof-to-wall junction, or a poorly sealed window trim joint above, and the corner becomes a sponge. Even newer fiber-cement siding can be undermined by a pine corner that was primed poorly or installed tight to the concrete walkway.
I often see three predictable failure patterns in Seattle trim repair. First, bottom rot within the lowest 6 to 12 inches, where splashback and capillary action saturate the end grain. Second, hidden decay behind paint at the mid-height nail lines, usually a sign the housewrap was punctured or the siding seam was never flashed. Third, systemic degradation running the full height of the board, often tied to a missing drainage gap behind the siding or an unflashed ledger attached for a deck or canopy.
Triage before you touch a saw
The fastest way to waste money on exterior trim repair is to replace the obvious soft corner without finding the leak that fed it. A systematic dry rot inspection is not complicated, but it does need discipline.
I start with a moisture meter and a sharp awl. Probe the lower 18 inches, then the top and bottom of each trim joint, then the first course of siding adjacent to the corner. Look for a reading above 16 percent, or wood that gives under firm pressure. Scan uphill until you find a plausible source: a downspout discharge that hits the wall, a mitered crown with open seams, a light fixture without a gasket, a missing z-flashing where horizontal trim intersects the corner, or a roof step flashing that terminates behind siding without a kick-out. On modern assemblies, I’ll also pop a few siding nails and pull a small section to confirm there is a drainage plane and intact housewrap. If we find systemic moisture, we are talking about siding repair Seattle homeowners should do sooner rather than later, not just a cosmetic fix.
Good siding contractors in Seattle will also check grade. Soil or mulch built up against the trim is a reliable rot accelerator. You need 6 to 8 inches of clearance to the dirt and 1 to 2 inches above hardscape. I have seen perfect prime and paint fail because the bottom of the corner was set directly on a paver where winter puddles never fully evaporate.
Choosing materials that survive our climate
You can rebuild a corner board from several materials, each with trade-offs. Your budget, the look of the house, and how much maintenance you accept will guide the choice.
Primed finger-jointed pine is common on spec homes. It installs cleanly and paints well, but it needs a meticulous prime on all cuts, a drip detail at the bottom, and generous caulk at critical joints. In neighborhoods with heavy wind-driven rain, it will still outlast the original if installed correctly, but it is the least forgiving option.
Clear cedar behaves better in wet climates, especially vertical grain. It has natural resistance to decay, holds paint if properly primed with an oil-based or high-quality bonding primer, and can be milled to match older details on a Craftsman or Tudor. The cost is higher, and fasteners must be stainless or high-grade coated to avoid staining.
Engineered wood trim, like LP SmartSide, offers consistency and good impact resistance. It demands adherence to the manufacturer’s clearances, end sealing, and gapping requirements. It can be a smart middle ground when paired with a water-managed wall assembly.
Cellular PVC trim, like Azek, does not rot. It cuts like wood, takes paint, and is a strong choice on highly exposed walls. It moves more with temperature than wood does, so you must allow for expansion with proper joints and adhesives. Where the home’s architecture leans traditional, PVC can look too crisp unless you ease edges and match profiles. If I’m replacing only the lower 18 inches of a wood corner, I avoid mixing PVC with wood in the same run because of differing movement.
Fiber-cement trim is durable but brittle. At corners, its weight and fastener requirements can complicate small repairs, yet for full-height rebuilds it holds up well in Seattle weather. You need diamond blades, specific nails, and dust control.
I talk clients through these options with examples from houses we maintain. On a 1913 Queen Anne with delicate shadow lines, we used clear cedar, scarfed joints, and a traditional drip. On a Beacon Hill contemporary with flush detailing and exposed weather, we used PVC with glued scarf joints and backer blocks for rigidity.
Rebuild philosophy: fix the cause, not just the symptom
A rot repair contractor who treats the corner in isolation sets you up for a repeat visit. When I bid seattle dry rot repair, I include source correction. If a roof-to-wall transition lacks a kick-out flashing, we install one. If a downspout dumps against the siding, we reroute it. If the house lacks a drainage plane, we have an honest conversation: spot repairs can buy you time, but siding replacement services Seattle WA homeowners consider every 20 to 30 years become cost-effective once failures are systemic.
Budget matters. I often split work into phases. Phase one handles safety and active leaks: rebuild the worst corner, add kick-outs, fix downspouts, restore clearances. Phase two addresses remaining failed trim and any suspect siding panels. Phase three looks at paint and maintenance. This pragmatic sequencing lets you stop water now while planning for larger siding contractors in Seattle scope later.
How we execute a corner board rebuild
No two houses are the same, but a well-executed corner rebuild follows a rhythm. This is the spot where DIY often goes sideways due to skipped steps or rushed weatherproofing. Below is a compact field checklist my crew uses to keep the work tight and predictable.
- Protect surroundings: set plastic to catch paint chips, lay down tarps, move landscaping as needed, and confirm utilities and wires are clear of fastener paths. Map moisture and source: probe, meter, and mark soft zones; identify and plan fixes for upstream water paths like missing flashings or unsealed penetrations. Deconstruct carefully: score caulk lines, pull fasteners, remove the corner board without shredding nearby siding, and open enough wall to see the sheathing and any damaged framing. Repair the substrate: cut back to sound wood, sister or replace studs and sheathing as needed, and treat marginally stained areas with a borate preservative before rewrapping. Rebuild and seal: install new flashing as required, integrate housewrap with proper shingle laps, set the new corner with correct clearances and back-primed cuts, fasten properly, gap and seal joints, and create a durable bottom drip detail.
That last item is where the battle is won. The housewrap and flashing integration must be correct. A corner is not just trim, it is a termination, and the layers behind it need to shed water, not trap it.
Housewrap, flashing, and the physics of drainage
Let’s talk about the layers. Behind the siding, you should have a water-resistive barrier, usually a housewrap, with a vertical drainage path. That path can be a rainscreen gap created by furring strips or a textured wrap. Seattle’s wetting and drying cycles benefit noticeably from a small air space. If I open a wall and find the siding flattened directly onto sheathing, I at least create a micro-gap with a rainscreen mat in the area I’m rebuilding. It is not a perfect substitute for a full rainscreen, but it is better than reinstalling a water trap.
At roof-to-wall intersections, the step flashing should turn out over the housewrap, not behind it. Where the roof ends at a wall, a kick-out flashing throws water into the gutter instead of letting it wash the siding at the corner. I have rebuilt countless rot-damaged corners that existed purely because someone forgot or dismissed a kick-out. It is a small piece of metal with an outsize effect.
Horizontal trim that meets a corner needs a z-flashing. That flashing should sit behind the upper wrap and out over the lower, with the trim lapped so water cannot get behind the corner. When you reinstall the corner board, you set it off the deck or walkway by 1 inch to avoid wicking, and off soil by at least 6 inches. End grain at the bottom gets sealed with primer, then a high-solids topcoat, before it ever sees daylight.
Fasteners, joints, and sealants that actually last
The best material installed with the wrong fastener will fail early. In Seattle, stainless steel earns its keep. Galvanized nails are acceptable for many trims, but they still can stain cedar and lose coating in salt air near Puget Sound. We use ring-shank stainless siding nails sized so they penetrate the studs by at least an inch, and we avoid overdriving which crushes wood fibers and invites cracking.
On long runs, scarf joints beat butt joints for shedding water, but only if oriented so the lap directs water outward. Every cut face gets primer on all sides. On PVC, we use the manufacturer’s recommended adhesive to weld joints. For wood, a small amount of high-quality exterior wood glue in a scarf joint can help, but the primary defense remains the paint and the slope.
Caulking is not a structural element. It is a gasket, and a flexible one at that. Use a high-performance urethane or silyl-terminated polyether for longevity. Tool it to a proper hourglass shape over a backer rod where gaps are wide. Avoid smearing caulk over wet or dirty surfaces, and avoid using it as a fix for missing flashing. If you find a spot where water runs into a joint by gravity, stop and fix the geometry rather than reach for a bigger caulk gun.
Matching profiles and paint on older homes
Seattle’s older housing stock, especially pre-war houses, carries distinctive trim profiles. Replacing a rotted corner on a 1920s bungalow is not just slapping on a 3.5 inch stock board. The original likely has a quirk, a reveal, or a beaded edge. I keep sample profiles from local mills and, when needed, have a corner milled to match. The cost difference for one or two corners is modest, and the curb appeal is noticeably better. Paint matching also matters. Even when we plan a whole-house repaint next season, I spot-prime with an oil or bonding primer, then two coats of finish at the repair. If the house is overdue for paint, we discuss a broader scope because patching paint on a failing dry rot repair Seattle coating is a short-term solution.
An anecdote that sticks with me: a Wallingford foursquare with seven years on a high-quality paint job. One back corner failed at the bottom. We found mulch was piled high, and a downspout elbow had shifted. We rebuilt only the lower 24 inches, installed a cedar plinth with a sloped top and a 3/8 inch drip kerf, raised soil and bark away from the foundation, and reset the downspout. That was five years ago. The paint at that corner still looks new because the water no longer lives there.
Costs, scope, and when to stop patching
Homeowners ask for numbers early. A straightforward lower-section corner repair with pine or cedar, no framing rot, and no special access typically falls in a mid-three-figure to low-four-figure range per corner in the Seattle market. Add framing repairs, tall ladder work, PVC materials, or metal flashings at a roof tie-in, and the range widens. If two adjacent walls show elevated moisture and multiple corners are soft, we talk about broader trim and siding repair. At some point, a series of patches costs more than targeted siding replacement services Seattle WA homeowners can plan in phases.
One rule of thumb I use: if more than 25 to 30 percent of a wall face’s trim and siding requires repair, replacement becomes economically rational. This is where reputable siding contractors Seattle WA residents recommend can add value through a comprehensive plan rather than whack-a-mole fixes. A full tear-off and re-side with a proper rainscreen and modern flashings can extend maintenance intervals and make future painting cheaper.
Common mistakes I still see and how to avoid them
The repeat offenders are simple, which is why they persist. People set the new corner tight to the concrete or deck. They forget to seal end grain. They caulk the bottom closed, trapping water. They skip kick-outs, then wonder why the corner rots again. They nail only to the sheathing, leaving the board to move and crack with seasonal changes. Or they cover obvious failures with a new layer of trim, a bandage that hides decay until the repair gets twice as large.
Another misstep is cosmetic caulking over dirt and chalking paint. Sealant adheres to the chalk, not the wood, then peels. A good dry rot repair Seattle homeowners appreciate starts with surface prep: clean, dry, warm enough for products to cure. If we get a wet week, we tent the area and run heaters or reschedule. The calendar matters in our climate.
Preventive maintenance that actually works
If you want to stretch the lifespan of your trim and siding, a little attention goes far. I advise clients to walk the house twice a year. After the first fall storm and after spring pollen, look for open caulk joints, peeling paint at lower corners, and gaps at horizontal trim that meets a corner. Touch up caulk and paint before the wood shows, and keep the first 6 inches of the wall clear of Discover more soil and debris. Clean gutters and ensure downspouts discharge into drains or away from the foundation. Where sprinklers hit the house, adjust them. Irrigation can destroy a corner in one season.
For homes near salt air or in shaded, damp exposures, consider a semi-annual light wash to remove biofilm that holds moisture. If your house has fiber-cement siding with wood corners, the trim can become the weak link. Swapping to an engineered or PVC corner on the worst weather wall can be a smart hybrid approach.
Hiring help: what to ask and expect
Seattle has many capable siding contractors. The ones you want for seattle trim repair will talk about water management first. When you interview, ask them to describe how they will integrate housewrap, where they will add or correct flashing, and how they will handle kick-outs. Ask what fasteners they use, how they prime cuts, and what clearances they will maintain to soil and hardscape. If they cannot answer without notes, keep looking.
Good contractors will propose source correction with each repair. They will photograph hidden conditions as they open the wall, and they will not pressure you into full siding unless your home truly needs it. They will offer options: like-for-like wood repair, upgraded materials at critical exposures, or a temporary patch if you must bridge to a larger project. They should be conversant in dry rot repair practices, and if structural members are compromised, they should bring a carpenter comfortable with framing. If you need a broader scope, look for siding repair Seattle specialists who can scale from a corner to a wall without losing attention to details.
A short case study from the field
A Ballard townhouse, 15 years old, with fiber-cement lap siding and finger-jointed pine corners. The HOA called for seattle dry rot inspection after one owner noticed a soft spot at the base of a north-facing corner. We tested all eight corners across the building. Six measured between 18 and 24 percent moisture at the lower 12 inches. Two showed active decay at mid-height next to a metal awning ledger.
We opened the worst corner. Behind the trim, the housewrap had been stapled tight to the sheathing with no flashing at the awning bracket penetrations. Water had followed fasteners into the sheathing, then migrated to the corner. The fix was not just swapping the board. We removed 36 inches of siding around the corner, repaired the sheathing, rewrapped with a textured drainage wrap, added new metal flashing at the awning brackets, installed kick-out flashings at two roof tie-ins, then rebuilt corners in cellular PVC with stainless fasteners and solvent-welded scarf joints. We left a 1 inch gap at the concrete walkway and a 6 inch gap to soil. We primed and painted to match.
The HOA wanted a durable solution without re-siding the entire complex. We prioritized the wettest corners and corrected the primary water intrusion points. Three years on, moisture readings are stable under 12 percent, and paint remains intact. It was not the cheapest path per corner, but it addressed cause and effect within a manageable budget.
When a rebuild becomes a redesign
Some corners are doomed by design. Flush modern rain screens without overhangs look sharp but demand impeccable execution. Where fascia dumps water down an outside corner or where a balcony penetrates through siding at a corner, you are dealing with a chronic wetting event. In such cases, I advise architectural tweaks: extend an eave by a few inches, add a drip edge to a parapet, or install a small diverter above a corner. These are small elements that reduce the water burden on the trim and siding. The cheapest gallon of paint is the one you don’t have to apply because your walls dry quickly after every storm.
A realistic path forward for homeowners
If your corner boards are soft at the bottom, you do not need to panic, but you do need action. Start with a focused inspection. If the problem is localized and the rest of the wall is sound, a proper Seattle trim repair can last as long as new. If moisture readings and visible clues point to a broader problem, engage siding contractors in Seattle who can evaluate the wall assembly, not just the surface. Ask for a plan that balances immediate repairs with long-term resilience.
The goal is a wall system that drains, dries, and looks right for your home’s style. Done well, a rebuilt corner is invisible because it fades into the architecture. What you do notice is what you do not see: paint that stays put, ants that do not return, and corners that feel solid under a firm thumb. That is the quiet satisfaction of trim and siding repair done the Seattle way, with water in mind and details that respect our climate.
Seattle Trim Repair 8338 20th Ave NW, Seattle, WA 98117 (425) 517-1751