Anacortes Siding Why Decks in Ship Harbor Take More Abuse Than Decks Inland
Ship Harbor sits close enough to the water that every deck out here deals with a combination most inland Skagit County homes never see: salt-laden air off the strait, driving rain that comes in sideways during winter storms, and a moss season that can stretch from October well into April. Any one of those is manageable on its own. Together, they shorten the life of a poorly built deck fast and they punish shortcuts that would go unnoticed somewhere drier.
Salt air corrodes fasteners and hardware years before it would inland. Driving rain finds every gap in flashing and every board laid too tight. And moss doesn't just look bad — it holds moisture against the deck surface and substructure, which is exactly what accelerates rot in wood framing and fastener failure in metal connectors. A deck built without those three factors in mind will show problems within a few seasons, not decades.
What This Means for Material Choice
This is part of why composite decking has become the default recommendation for homes in this stretch of Anacortes. It doesn't absorb water the way wood does, it doesn't need annual staining, and it resists the surface mildew and moss staining that wood decks fight constantly in a marine climate. That said, composite is not maintenance-free, and it's not immune to bad installation — the board itself is only part of what makes a deck last here.
What "Composite Decking" Actually Covers
Composite decking isn't one product — it's a category, and the differences matter more in a coastal climate than they do elsewhere.
Capped Composite
Most composite decking sold today is capped: a wood-plastic composite core wrapped in a polymer shell. The cap is what gives it stain, fade, and moisture resistance. Uncapped or lower-grade composite boards absorb more moisture at cut ends and exposed edges, which is a real liability in a climate with this much rain.
PVC / Cellular Decking
Fully synthetic PVC decking has no wood fiber at all. It handles constant moisture exposure well and won't take on water at cut ends, but it has its own trade-offs — different expansion and contraction behavior with temperature swings, a different look and feel underfoot, and typically a higher price point.
Our standard is to spec capped composite for most Ship Harbor decks unless a homeowner has a specific reason to go with PVC — proximity to standing water, a covered deck with limited airflow, or a preference for a particular finish. We'll walk through the honest trade-offs for your specific site rather than defaulting to whatever's easiest to install.
What a Correct Installation Looks Like Here
The board is maybe a third of what determines how long a composite deck lasts in this climate. The framing, flashing, and fastening decisions underneath it matter just as much, and they're where corners get cut most often.
Ledger Flashing
Where the deck attaches to the house, the ledger board connection is the single most common source of hidden water damage on any deck, composite or wood. Proper flashing — installed so water sheds down and away from the house framing, not just tucked in behind the siding — is non-negotiable given how much driving rain this area gets in the winter months.
Joist Protection
Even under composite decking, the substructure is typically pressure-treated lumber, and pressure-treated wood still rots if water sits on it. We run joist tape over the tops of joists and beams to keep fasteners from creating a wicking point and to keep standing moisture off the wood itself. Skipping this step is one of the most common shortcuts we see on decks that failed early.
Hardware and Fasteners
This is where salt air does the most damage if it's ignored. Standard galvanized hardware corrodes faster this close to the water. We use stainless steel or coated fasteners rated for coastal exposure, along with structural connectors rated for the same environment. It costs a little more up front and it's the difference between hardware that's still solid in fifteen years and hardware that's rusting through in five.
Board Spacing and Drainage
Composite boards need consistent gapping — both between boards and at the perimeter — to let water drain and air move underneath. Too tight, and you trap moisture against the board and the substructure below; that trapped moisture is exactly what feeds moss and mildew growth on the surface and framing rot underneath.
Moss and the Long Wet Season
Moss doesn't grow on composite decking the way it grows on wood, but it absolutely will grow ON TOP of a composite deck surface if moisture sits there and airflow underneath is poor. In a location with a moss season this long, that's a real consideration, not a hypothetical.
Where Moss Actually Takes Hold
The usual spots are shaded corners, areas under overhangs where boards don't get sun exposure, and decks built low to the ground with limited clearance for air to circulate underneath. None of these are reasons to avoid composite decking — they're reasons to get the framing height, drainage slope, and board spacing right during installation.
Surface Texture Matters
Composite boards come in a range of surface textures, from smooth to heavily wood-grained. Heavier texture patterns can hold onto grime and organic buildup a little more than smoother finishes in a climate this wet. It's a minor factor compared to framing and drainage, but worth discussing when you're picking a board profile for a shaded Ship Harbor lot.
Composite vs. Wood vs. PVC for This Climate
| Factor | Wood | Capped Composite | PVC |
|---|---|---|---|
| Salt air / moisture resistance | Poor without constant upkeep | Good | Very good |
| Moss/mildew resistance (surface) | Poor | Good | Good |
| Maintenance | Annual staining/sealing | Occasional washing | Occasional washing |
| Typical lifespan (correctly installed) | 10-15 years | 25-30+ years | 25-30+ years |
| Upfront cost | Lowest | Moderate | Highest |
| Feel/appearance | Natural wood grain | Wood-look, wide range | Cleaner, more uniform look |
Wood remains the lowest upfront cost, and some homeowners still prefer the look and feel of real cedar. That's a legitimate choice — but it comes with an honest maintenance commitment in a climate that punishes neglected wood fast. For most Ship Harbor homeowners who want to install a deck and not think about it every summer, capped composite is the middle ground: strong moisture and salt resistance, reasonable cost, and a lifespan that justifies the price difference over wood.
Our Process for a Ship Harbor Deck Project
1. Site Visit and Assessment
We look at sun and shade exposure, existing drainage patterns, ledger connection points, and how close the deck sits to grade. All of that affects both material recommendation and framing details before we quote anything.
2. Framing and Flashing
Substructure goes in first — pressure-treated framing, joist tape, coastal-rated hardware, and ledger flashing done correctly at the house connection. This stage is not visible once the deck is finished, but it's the stage that determines whether the deck is still solid in twenty years.
3. Decking Installation
Composite boards go down with manufacturer-specified gapping and hidden or approved fastening systems, following the board manufacturer's installation requirements to keep warranty coverage intact.
4. Railings, Stairs, and Finish Details
Railing systems, stair stringers, and edge trim get installed and checked for level, secure attachment, and code compliance where applicable.
5. Walkthrough
We walk the finished deck with you, cover basic care, and answer questions about how the specific board you chose handles cleaning and seasonal upkeep.
Maintaining a Composite Deck in a Marine Climate
Composite decking cuts maintenance dramatically compared to wood, but "low maintenance" isn't "no maintenance," especially this close to the water.
- Sweep off debris, needles, and leaves regularly — trapped organic matter is what feeds moss and mildew on the surface
- Wash the deck surface with soap and water (or a manufacturer-approved cleaner) at least once or twice a year, more often in shaded areas
- Check that drainage gaps between boards stay clear of debris, especially after fall leaf drop
- Inspect railing posts and stair connections annually for any looseness
- Rinse off salt spray buildup after major storms if your deck faces the water directly
- Keep an eye on the area underneath the deck for standing water or poor drainage after heavy rain events
Why It Matters That We Already Work in Ship Harbor
A crew that's built decks throughout this specific stretch of Anacortes already knows which corners of a lot tend to hold moisture, which board manufacturers actually stand behind their coastal warranty claims, and which fastening details hold up against salt air over time versus which ones look fine on installation day and fail in year six. That's not something you get from a general contractor working here for the first time.
It also means we're not guessing about permitting requirements or typical lot conditions in the area — we've already been through it on other Ship Harbor projects. That local familiarity translates into fewer surprises during the build and a deck that's actually specified correctly for where it sits, not just built to a generic standard.
Getting Started
If you're planning a new deck or replacing one that's showing its age, we're happy to come take a look, walk the site with you, and put together a straightforward estimate — no pressure, no upsell on material you don't need. Use the form below to get in touch and we'll set up a time to visit your Ship Harbor property.