Burlington Guemes Island Is a Different Siding Job Than the Mainland
Guemes Island sits just off Anacortes in Skagit County, a short ferry ride from Burlington, and it takes weather most mainland homes never see in the same combination. Salt-laden air off Guemes Channel and Rosario Strait, driving rain that comes in sideways off the water, and a long, damp moss season that can run from fall through spring all work on a home's exterior at the same time. A siding installation here has to account for all three, not just one. General siding advice written for a subdivision twenty miles inland doesn't fully apply once you're on an island with saltwater on multiple sides and tree cover holding moisture against the house.
This page is about one job, done right, in one place: siding installation for Guemes Island homes. Not a general overview of siding, and not a sales pitch for every product on the market — just what island conditions actually demand, what a correct installation looks like, and why the work benefits from a crew that already understands the ferry schedule, the moisture load, and the way salt air ages materials differently than it does a few miles inland.
What Salt Air, Driving Rain, and Moss Season Actually Do to Siding
Salt Air
Airborne salt is corrosive to metal fasteners, flashing, and trim, and it accelerates the breakdown of finishes that aren't formulated to resist it. On an island, salt exposure isn't occasional — it's constant, riding in on wind off the water even on a clear day. Siding, fasteners, and flashing that would perform fine forty minutes inland can show premature corrosion or finish failure on Guemes Island if they weren't chosen with that exposure in mind.
Driving Rain
Rain that comes in nearly horizontal during a Skagit County storm doesn't just wet the siding surface — it tests every seam, joint, and penetration in the wall assembly. Water-resistive barriers, flashing details, and the way siding courses lap over one another all matter more here than they would in a climate with gentler, more vertical rainfall. A siding job that looks fine on a calm day can fail during the first real wind-driven storm if the water management behind the siding wasn't done correctly.
Moss Season
Shade, humidity, and tree cover on Guemes Island create long stretches where siding surfaces stay damp. Moss and algae don't just look bad — sustained dampness against a wall surface is what eventually leads to rot in wood-based products and finish breakdown in less durable materials. A siding choice and installation detail that sheds water quickly and dries fast matters more here than in a drier part of the county.
What a Correct Siding Installation Actually Involves
Siding is a system, not a single layer. Getting the visible surface right means nothing if the layers behind it are wrong. On an island property exposed to salt, wind-driven rain, and prolonged dampness, every step below carries more weight than it would in a milder setting.
- Water-resistive barrier: a continuous, properly lapped weather barrier behind the siding, installed so water is always directed outward and down, never trapped.
- Flashing at every penetration: windows, doors, vents, and hose bibs all need flashing detailed to shed water into the barrier system, not behind it.
- Proper starter course and clearances: siding started level and square, with correct clearance from grade, decks, and roof lines so water doesn't wick into the bottom edge.
- Correct fastener type and placement: fasteners rated for the siding material and for the corrosive coastal air, driven to the manufacturer's depth and spacing, not just "snug."
- Caulking and sealant only where specified: over-caulking a joint that's supposed to breathe traps moisture instead of releasing it.
- Field-cut edges sealed and painted: any cut edge on a fiber cement board needs to be sealed before it's exposed to island weather, not left raw.
Skipping or rushing any one of these doesn't usually show up right away. It shows up two or three winters later, as a stain, a soft spot, or a section that's failing while the rest of the wall looks fine.
Comparing Siding Materials Under Island Conditions
Homeowners on Guemes Island often ask what actually holds up out here versus what holds up "on paper." The table below reflects how common siding materials tend to behave specifically under salt exposure, wind-driven rain, and extended damp/shade conditions — not their general reputation.
| Material | Salt Air Behavior | Wind-Driven Rain Behavior | Moss/Damp Behavior |
|---|---|---|---|
| Vinyl | Can fade and become brittle faster under salt and UV combined | Panels can warp or loosen; seams rely on lap fit | Doesn't rot, but moss/algae grow on the surface and need cleaning |
| Cedar | Attractive but needs regular refinishing to resist salt-driven weathering | Prone to cupping and checking if finish fails | Susceptible to rot and moss staining without diligent upkeep |
| Primed spruce/wood composite | Prone to accelerated finish and edge failure in salt air | Swelling at edges and joints if water gets past the primer | Higher rot risk if damp conditions persist |
| LP SmartSide (engineered wood) | Holds up reasonably but edges and cuts need diligent sealing | Performs well when installed to spec; edge swelling is the main risk | Manageable, but any coating gap invites moisture into the wood strand core |
| James Hardie fiber cement | Non-combustible cement composition resists salt-driven finish breakdown; ColorPlus finish engineered for coastal UV/salt exposure | Dense board and correct lap/flashing detail manage wind-driven rain well | Doesn't feed rot the way wood-based products can; surface can still host moss and needs the same periodic cleaning as any siding |
This is why we install James Hardie fiber cement exclusively. It isn't that other products are junk — cedar has genuine appeal, LP SmartSide performs adequately when installed correctly, and vinyl is inexpensive and low-maintenance in mild climates. But on a Skagit County island with constant salt exposure, wind-driven rain, and long damp seasons, we've standardized on the one product line engineered specifically for climates like this, with a factory-applied finish and a transferable warranty that backs it up. We'd rather install one product well than install several products with trade-offs we'd have to explain away later.
Why We Don't Install Vinyl, LP SmartSide, Cedar, or Primed Spruce Here
Vinyl's biggest weakness on an island is UV and salt working together on the finish over time, plus panels that can loosen or oil-can in strong, gusty wind off the water. Wood-based products — cedar, primed spruce, engineered wood — all share the same underlying vulnerability: if water gets past the finish and into the wood or wood-strand core, rot follows, and salt air combined with a long moss season makes that finish work harder than it does inland. None of these are bad products in the right setting. They're just not the products we've chosen to stand behind for homes exposed to this specific combination of salt, rain, and dampness.
Our Process for a Guemes Island Siding Project
Working on an island adds logistics that a mainland job doesn't have, and we plan around them rather than treating them as surprises.
- On-site assessment: we look at the specific exposure of the home — how much direct salt wind it takes, how much shade and moisture it holds, and the condition of the existing wall assembly underneath the current siding.
- Material and color selection: we walk through the relevant Hardie product line and ColorPlus finish options suited to the home's exposure and the owner's preference.
- Scheduling around the ferry: materials, crew, and equipment moves are planned around the Guemes Island ferry schedule so the job runs on a predictable timeline instead of losing days to logistics.
- Tear-off and inspection: when old siding comes off, we check the sheathing and water-resistive barrier underneath for hidden moisture damage before anything new goes up.
- Installation to manufacturer spec: correct flashing, fastening, clearances, and sealed cut edges, installed to James Hardie's published installation requirements — which is also what keeps the manufacturer's warranty intact.
- Final walkthrough: we go over the completed work with the homeowner, including what maintenance to expect given the island's specific conditions.
What Guemes Island Homeowners Should Expect for Upkeep
Correctly installed Hardie siding is low-maintenance, but "low-maintenance" isn't "no-maintenance," especially in this environment. A short seasonal routine keeps a good installation performing the way it's supposed to.
- Rinse salt residue and moss/algae buildup off siding surfaces periodically, especially on shaded or north-facing walls.
- Keep gutters clear so water isn't overflowing and running down the siding face during heavy rain.
- Trim back vegetation that's holding shade and moisture directly against the wall.
- Check caulking at trim and penetrations annually and have any gaps resealed before winter storms.
- Address any impact damage or exposed cut edges promptly rather than letting them sit through a wet season.
Cost Factors for Guemes Island Siding Projects
Every home is different, but the following factors typically move the price of a siding installation on the island more than they would on a comparable mainland job.
| Factor | Why It Matters on Guemes Island |
|---|---|
| Ferry and logistics scheduling | Material deliveries and crew transport are planned around ferry sailings, which affects project timeline more than cost directly, but poor planning adds delays |
| Existing sheathing condition | Homes with long-term moisture exposure sometimes need sheathing repair before new siding goes on |
| Wall exposure and complexity | Homes facing open water or exposed ridgelines need more attention to flashing and fastening detail |
| Trim and detail work | Corner boards, window trim, and fascia detailing add labor regardless of location |
| Product line and finish selection | Different Hardie product lines and ColorPlus finish options carry different material costs |
We provide a specific, itemized estimate after seeing the home — broad ranges without an on-site look aren't useful to an island homeowner trying to plan a real budget.
Why It Matters That We Already Work on Guemes Island
A crew that's worked Guemes Island before already understands the ferry schedule and builds it into the project timeline instead of discovering it mid-job. They know what salt exposure and long moss seasons do to a wall assembly over years, not just what a spec sheet says. And they've already made the material decision — James Hardie fiber cement, installed to spec — based on watching how different products actually age out here, rather than defaulting to whatever's cheapest to truck over. That local track record is part of what a homeowner is paying for when they hire a crew that already knows the island, not just the mainland side of Skagit County.
If you're planning a siding project on Guemes Island, we're happy to take a look at your home and put together a straightforward, no-pressure estimate — just fill out the form below.