Lynden Window Composite Decking Built for Ferndale's Coastal Whatcom County Climate
Ferndale sits close enough to the water and to the open, low-lying farmland of the Nooksack lowlands that its homes take on a specific mix of exterior stress: salt-tinged marine air, rain that arrives sideways more often than it falls straight down, and a moss season that can run most of the year on shaded ground. A deck feels that mix more directly than almost anything else attached to the house. It has no roofline or wall assembly protecting it — it sits outside, flat to the sky, absorbing whatever the weather does all year long.
Composite decking is built to handle that kind of exposure better than wood, but "composite" isn't one product. Quality, construction, and how well a given board actually resists Ferndale's specific conditions vary a lot between manufacturers. This page covers what a Ferndale deck actually needs from composite decking, what a correct installation involves here, and why it matters to hire a crew that already works this part of Whatcom County.
What Ferndale's Climate Actually Does to a Deck
Salt Air and Fastener Corrosion
Even homes set back from the immediate shoreline get a steady dose of salt-laden air moving through this part of the county, and a deck sits directly in it with nothing shielding the surface or the hardware underneath. Salt accelerates corrosion in exposed metal — fasteners, brackets, post hardware, railing connectors — and a fastener that's begun corroding loses holding strength well before it looks obviously bad. That matters more on a deck than on most exterior surfaces, since it's a structure people actually stand and walk on.
Wind-Driven Rain
Rain in this part of Whatcom County rarely falls straight down. Wind pushes it sideways, driving it up under railings, into ledger connections, and between deck boards that aren't gapped correctly for drainage. A decking surface that would shed water fine on a calm, dry day can still trap moisture the moment wind gets involved, and around Ferndale's more open, lower-lying terrain, that wind exposure tends to be a bigger factor than it is on more sheltered lots further inland.
A Moss Season That Runs Most of the Year
Mild temperatures and near-constant moisture give moss and mildew a long growing season across Whatcom County, and a horizontal deck surface is one of the first places it takes hold — it holds water longer than a vertical wall and stays damp between rain events. Shaded decks and north-facing surfaces usually show it first. Any decking material with even slight surface porosity gives moss something to grip onto over time.
What "Composite Decking" Actually Means
Composite decking is generally made from a blend of wood fiber and plastic, though the ratio, the plastic type, and how the board is finished vary significantly between product lines. Two distinctions matter most for a Ferndale installation.
Capped vs. Uncapped Composite
Capped composite boards have a protective plastic shell wrapped around a wood-plastic composite core, which resists moisture absorption, staining, and UV fade far better than the core material would on its own. Uncapped composite is the older style of the product — the wood-plastic blend is exposed on all sides, so it can absorb moisture and is more prone to mold growth, fading, and surface wear over time. In a climate with this much sustained dampness, that difference shows up faster than it would somewhere drier, which is why we standardize on capped composite for Ferndale installs.
Composite vs. Cellular PVC
Some manufacturers also offer fully cellular PVC decking, which contains no wood fiber at all. PVC resists moisture absorption completely and some lines run cooler and stay lighter-looking longer, but it can flex more under heavy point loads and generally costs more upfront than capped composite. We'll talk through whether capped composite or PVC makes more sense for a specific deck based on shade, budget, and how the space will actually get used — there isn't one right answer for every property.
What a Correct Composite Deck Installation Involves Here
The decking boards get most of the attention, but the framing, fasteners, and drainage details underneath are what actually determine whether a Ferndale deck lasts. A build done right for this climate includes:
- Framing material rated for sustained moisture exposure — pressure-treated lumber sized correctly for the span and load, not a generic lumber-yard spec
- Stainless steel or coated coastal-grade fasteners throughout, not standard hardware that starts corroding in salt-laden air within a few seasons
- Hidden fastener systems on the surface where the product allows, reducing exposed metal and giving a cleaner walking surface
- Correct board gapping for drainage and thermal movement, since composite expands and contracts with temperature differently than wood does
- Proper ledger board flashing where the deck ties into the house, since that connection point is one of the most common places moisture works its way in
- Joist spacing matched to the specific composite product's span rating rather than a standard wood-framing layout
- Railing and post attachment sized for the site's actual wind exposure, especially on elevated decks or more open lots
- Ventilation and drainage beneath the deck so moisture doesn't sit against the framing between storms
Skipping any one of these rarely causes a visible problem on day one. It shows up a few winters later as a soft joist, a loosening railing post, or corroding fasteners staining the boards around them.
Composite Decking Compared to the Alternatives
| Material | Handling Salt Air & Moisture | Moss Resistance | Typical Upkeep |
|---|---|---|---|
| Capped composite | Strong — cap layer resists moisture, staining, and fade | Good on most product lines | Occasional washing; no sealing or staining |
| Cellular PVC | Excellent — no wood fiber to absorb moisture at all | Strong, smooth non-porous surface | Occasional washing; no sealing or staining |
| Uncapped composite | Moderate — some moisture absorption at exposed fiber | Fair; more prone to buildup over time | Periodic cleaning to manage mold and staining |
| Cedar | Moderate — natural resistance, but needs sealing to hold up | Fair when sealed and maintained | Regular oiling or sealing |
| Pressure-treated wood | Weak against sustained salt exposure over time | Poor without regular treatment | Regular sealing or staining |
Exact costs depend on the home, the deck size, and site access, which is why we walk the property in person before quoting instead of pricing off a generic sheet.
How Our Process Works
We start with a site visit to look at what's actually there — existing structure condition if it's a replacement, drainage and grade around the deck area, sun and shade patterns through the day, and how exposed the lot is to prevailing wind and weather. From there we walk through composite product options that fit the budget and how the space will get used, whether that's a quiet spot off the back door or something built for entertaining.
Permitting in Ferndale and the rest of Whatcom County generally follows standard setback, structural, and elevation requirements, and we handle that as part of the job instead of leaving it for the homeowner to sort out. Once permitted, the build follows the sequence above — framing first, sized and fastened for the site's actual exposure, then the composite surface, railing, and any stairs or trim work. We finish with a walkthrough covering what the specific product you chose actually needs going forward, which for most composite lines is minimal, but not nothing.
What Composite Decking Still Needs From You
Composite decking is low-maintenance compared to wood, not maintenance-free. A little routine attention keeps it performing the way it's supposed to in this climate:
- Rinse or wash the surface periodically to clear salt residue, pollen, and organic buildup before it works into the cap layer
- Keep gaps between boards clear of leaves and debris so water and airflow can move through the way the design intends
- Check railing posts and hardware once a year for early corrosion or loosening, especially heading into the wet season
- Trim back overhanging branches or plants that hold moisture against the deck or block sun and airflow across the surface
- Address any soft framing or standing water underneath right away — that's structural, not cosmetic, and it doesn't improve on its own
Why It Matters That We Already Work Ferndale
A crew that mostly builds decks further inland can still install composite decking competently, but a Ferndale job has variables that don't come up as often elsewhere in the county — sustained salt exposure from the water and lowlands nearby, wind loads tied to more open terrain, and a moss season long enough that drainage and gapping details matter more here than in a drier climate. Working this area regularly means we're not guessing at those requirements on your project. We know which composite lines actually hold up against Ferndale's specific combination of salt air, wind-driven rain, and moss, and which fastener grades and framing details are worth the extra time rather than an upsell.
That familiarity also shows up in the smaller judgment calls — how to orient a deck for the wind a particular lot actually sees, and being straightforward about what a deck here realistically needs to last versus what's just an extra line item on an invoice.
Get a Free, No-Pressure Estimate
Whether you're replacing a tired wood deck, building new, or just want an honest read on what composite decking would take on your Ferndale property, we're happy to walk the site with you and lay out the options plainly. Reach out using the form below to schedule a free estimate, no pressure and no upsell script.