Mount Vernon Why Anacortes Siding Takes a Different Kind of Beating
Anacortes sits out on Fidalgo Island, wrapped by the Guemes Channel, Rosario Strait, and the open water toward the San Juans. That waterfront position is exactly why the town is beautiful and exactly why its siding wears out faster than siding twenty miles inland in Mount Vernon or Burlington. Homes here deal with three things at once, year-round: salt-laden air off the strait, driving rain that comes in sideways during winter storms, and long stretches of damp, low-light weather that keep north- and west-facing walls wet for days at a time.
None of that is unique to any one house in Anacortes — it's the baseline for the whole peninsula, from the neighborhoods near the ferry terminal down through the residential streets closer to March Point and out toward the water on the west side of town. Siding that's engineered for a drier, more sheltered climate simply doesn't hold up the same way out here.
What Salt Air Actually Does to a House
Salt air isn't just a coastal nuisance — it's a slow chemical process. Airborne salt is hygroscopic, meaning it pulls moisture out of the air and holds it against whatever surface it lands on. On siding, that means a thin film of salt-moisture sits on the exterior far more often than plain rainwater would, especially on walls facing the water or exposed to prevailing wind.
- Metal fasteners and trim corrode faster, which shows up first as rust streaking below nail heads or flashing edges.
- Paint and coatings break down quicker under repeated salt-moisture cycling, especially on lower-quality or field-applied finishes.
- Wood-based sidings (cedar, primed spruce, some engineered wood products) absorb that moisture into the substrate itself, which is where the real damage — swelling, delamination, rot at seams — starts.
- Caulked joints around windows and trim dry out and crack sooner than they would in a drier inland climate, opening small gaps that let moisture behind the siding.
None of this happens overnight. It's cumulative — a few years of it and a house on the water side of Anacortes can look noticeably more weathered than a similar house fifteen minutes inland, even with the same maintenance schedule.
Driving Rain and the "Wrong Side" of the House
Skagit County gets plenty of straightforward, straight-down rain. Anacortes gets that plus wind-driven rain that comes in at an angle off the water, which changes how siding needs to perform. Wind-driven rain doesn't just run down a wall — it gets pushed sideways and upward into laps, seams, and butt joints that were never designed to shed water from that direction.
This is where installation quality starts to matter as much as the material itself. Lap siding needs the right exposure and overlap to shed angled rain, butt joints need to be caulked or flashed correctly, and any siding that isn't rated for direct, sustained moisture exposure is going to show problems first on the west- and south-facing walls that catch the brunt of Anacortes storms. We see this pattern often enough on inspection calls that it's one of the first things we check — which walls are taking the weather, and whether the existing siding and flashing were ever detailed for it.
The Long Moss Season
Western Washington's moss season is long everywhere, but the combination of marine humidity, shade from mature trees, and slower drying time on north-facing walls makes Anacortes especially moss-prone. Moss doesn't just grow on roofs — it colonizes siding, too, particularly in shaded corners, under eaves, and anywhere airflow is limited.
The problem isn't cosmetic. Moss holds moisture directly against the siding surface for extended periods, which accelerates whatever moisture-related breakdown the material is already prone to. On wood-based products, that's a direct path to rot. On siding with a weak factory finish, it's a path to premature paint failure and staining that's difficult to fully clean off without damaging the surface underneath.
Where Moss Tends to Take Hold
- North- and east-facing walls that get the least direct sun
- Areas shaded by trees, fences, or neighboring structures
- Behind shrubs and landscaping planted close to the foundation
- Under eaves and around downspouts where runoff collects
- Any spot where two wall planes meet and airflow is restricted
Why We Only Install James Hardie in a Climate Like This
Mount Vernon Siding installs James Hardie fiber cement siding exclusively — we don't install vinyl, LP SmartSide, Cemplank, Allura, primed spruce, or cedar. That's not a marketing position, it's a standard we settled on after years of doing exterior work across Skagit County, including plenty of jobs right here in Anacortes where the coastal conditions expose the weak points of other materials fastest.
Fiber cement is a mineral-based composite — cement, sand, and cellulose fiber — with no wood content to absorb and hold moisture the way cedar or engineered wood products can. It doesn't corrode like some metal siding options, and it's non-combustible, which matters in a region where wildfire smoke and ember exposure have become a bigger seasonal concern than they used to be. Hardie's ColorPlus factory finish is baked on under controlled conditions rather than field-applied, which gives it more consistent adhesion and better resistance to the kind of UV and moisture cycling that breaks down site-applied paint faster near the water.
James Hardie also builds regional engineering into its HZ5 product line specifically for climates like the Pacific Northwest — freeze-thaw cycling, sustained moisture exposure, and humidity are all accounted for in how the boards are formulated. That's a meaningful difference from a general-purpose siding product asked to perform in a marine environment it wasn't specifically designed for.
What We're Not Saying
We're not going to tell you cedar looks bad or that vinyl always fails — that's not honest, and it's not our call to make about a product on someone else's house. What we will say is that after enough Anacortes and Skagit County jobs, we stopped installing products that ask homeowners to fight the local climate with extra maintenance, and we standardized on the one that doesn't.
How a Siding Replacement Works Out Here
1. Inspection and Moisture Check
We start by walking the exterior and checking the walls that take the worst of the weather — usually the water-facing side and any shaded, moss-prone areas. If there's any sign of moisture intrusion behind the existing siding, we check the sheathing before quoting anything, because covering a hidden moisture problem with new siding just delays a bigger repair.
2. Removal and Sheathing Repair
Old siding comes off, and we address any rot, soft sheathing, or damaged flashing before anything new goes up. This step gets skipped by rushed jobs more than any other, and it's the single biggest predictor of how long a new siding installation actually lasts.
3. Weather-Resistive Barrier and Flashing
A correctly lapped weather-resistive barrier and properly integrated window and door flashing matter more in a wind-driven-rain environment than almost anywhere else in the county. This is the layer that protects the house if any water does get past the siding surface.
4. James Hardie Installation to Spec
Hardie siding is only as good as its installation. Manufacturer specifications call for correct nailing patterns, proper clearance at the bottom of the wall, and gapped, caulked, or flashed joints depending on the detail. We install to those specs, not shortcuts.
5. Final Walkthrough
We walk the finished job with the homeowner, check trim and caulk lines, and go over basic care — mainly keeping an eye on shaded, moss-prone spots going forward.
Comparing Siding Options for a Coastal Skagit County Home
| Factor | James Hardie Fiber Cement | Cedar / Primed Wood | Vinyl |
|---|---|---|---|
| Moisture absorption | Very low — mineral-based, doesn't swell | Absorbs moisture, prone to rot near water | Doesn't absorb, but seams can trap moisture behind panels |
| Salt air resistance | Strong — factory finish holds up well | Weathers and requires more frequent refinishing | Can chalk and fade faster in marine UV exposure |
| Moss/algae resistance | Good — hard, non-porous surface | Moss and mildew take hold more easily on wood grain | Moderate — moss grows on surface but doesn't penetrate |
| Fire resistance | Non-combustible | Combustible | Melts/deforms under heat, not fire-rated the same way |
| Maintenance | Occasional wash, minimal repainting with ColorPlus | Regular refinishing, sealing, rot checks | Low maintenance but can crack in impact and fade over time |
Roofing, Windows, and Decks in the Same Climate
Siding rarely fails in isolation out here — a roof with worn flashing, single-pane or failing-seal windows, or a deck with moisture damage all point to the same underlying issue: an exterior envelope that isn't keeping up with the coastal conditions. We handle roofing, windows, and decks alongside siding for exactly that reason. If we're already up close on a siding job and notice deteriorating roof flashing or a window that's letting moisture into the wall cavity, we'll tell you, because ignoring it doesn't make it go away — it just means the new siding fails sooner than it should.
Planning a Siding Project: What Affects Cost
- House size and wall complexity — more corners, dormers, and trim details mean more labor and material cuts
- Extent of hidden damage — rot or moisture behind existing siding adds repair scope before new siding goes up
- Siding profile and color — lap width, texture, and ColorPlus color selection affect material pricing
- Trim and accessory work — window trim, corner boards, and fascia detailing add scope beyond the flat wall area
- Access and site conditions — waterfront lots, steep grades, or limited access can affect labor time
We give straightforward, itemized estimates rather than vague ballpark numbers, because coastal jobs vary more than inland ones once hidden damage gets factored in.
A Local Crew That Understands This Coastline
A crew that mostly works inland jobs can still do competent work in Anacortes, but they're less likely to catch the details that matter here — which walls need extra attention for wind-driven rain, where moss is going to come back no matter what, and how salt air changes the maintenance conversation. Mount Vernon Siding works across Skagit County regularly enough that Anacortes conditions aren't a special case for us — they're a normal part of the week.
If you're weighing a siding replacement, a roof that's showing its age, aging windows, or a deck that needs attention, we're happy to take a look and give you a straightforward, no-pressure estimate — no hard sell, just an honest read on what your house actually needs.