Lynden Siding Composite Decking for Custer Homes
Custer sits close enough to the water and far enough into Whatcom County's wet season that a deck here takes a different kind of beating than one built inland or in a drier climate. Salt-tinged air off the coast, long stretches of driving rain, and a moss season that can run from fall through spring all work against a deck surface year-round. Composite decking was designed for exactly this kind of exposure, and for homeowners around Custer and the greater Lynden area, it has become the practical choice for anyone who wants a deck that still looks good five, ten, or twenty years out.
This page focuses specifically on composite decking as a local service in Custer — what the climate demands, what a correctly built deck actually involves, and how we approach the work when we're on site in your neighborhood.
What Custer's Climate Does to a Deck
Three things drive most of the deck problems we see out this way.
Salt Air
Homes closer to the water deal with a fine salt residue that settles on every exterior surface over time. On wood decking, that salt accelerates weathering and pulls moisture into the grain. On fasteners and hardware, it speeds up corrosion. Composite boards don't absorb salt the way wood fibers do, and when we spec hardware for a Custer job, we account for that exposure rather than treating it like an inland build.
Driving Rain
Whatcom County doesn't just get rain — it gets sideways rain, the kind that finds gaps in flashing, works its way behind fascia boards, and pools wherever drainage wasn't planned for. A deck surface that's rated for moisture is only half the equation. The structure underneath — ledger board attachment, joist protection, and drainage paths — has to be built assuming water will hit it directly and often.
Moss Season
Moss doesn't need much: shade, moisture, and time. Custer gets all three for a good part of the year. Any horizontal surface that stays damp and doesn't get regular sun exposure is a candidate for moss and algae growth. This matters for material choice, board spacing, and how a deck is oriented and detailed at installation.
Composite vs. Wood in This Climate
We install both materials, and wood still has a place on some projects. But for a straightforward comparison of how each holds up under Custer's specific conditions, here's how they generally stack up:
| Factor | Composite Decking | Pressure-Treated Wood |
|---|---|---|
| Moisture absorption | Minimal — capped boards resist water intake | Higher — wood fibers absorb and release moisture repeatedly |
| Moss and algae resistance | Better on capped/textured products; still needs airflow and cleaning | Prone to surface growth, especially in shaded, damp spots |
| Maintenance | Periodic washing; no staining or sealing required | Annual or biannual staining/sealing to prevent checking and rot |
| Splintering / warping | Rare on quality capped composite | Common over time, especially with repeated wet-dry cycles |
| Upfront cost | Higher material cost | Lower material cost |
| Long-term cost | Lower — fewer replacement boards, no refinishing labor | Higher over 15+ years once maintenance labor is factored in |
| Fastener exposure | Hidden-fastener systems common, reducing corrosion points | Typically face-screwed, more exposed hardware |
The honest trade-off: wood costs less to install today, composite costs less to own over time. In a climate that's actively working against exposed wood grain for eight or nine months of the year, that math tends to favor composite for most homeowners who plan to stay in the house a while.
What a Correct Composite Deck Installation Involves
Framing and Joist Spacing
Composite boards flex differently than wood and most manufacturers specify tighter joist spacing than a traditional wood deck would use — often 12" on center for diagonal or angled patterns instead of the wider spacing wood tolerates. Building to the composite manufacturer's actual span tables, not just "how we've always framed it," is what keeps a deck from developing a bouncy or spongy feel a few years in.
Ledger Attachment and Flashing
Given how much driving rain this area sees, the ledger board connection to the house is one of the highest-risk points on any deck. Proper flashing — installed so water sheds away from the house rather than behind the ledger — is not optional here. This is also the area most likely to hide a problem for years before it shows up as rot in the rim joist or sheathing.
Drainage and Ventilation Underneath
A deck that traps moisture underneath is a deck that stays damp longer after every rain, which is exactly the condition moss needs. Correct grading, gaps for airflow, and keeping vegetation and debris from building up under low decks all matter more here than in a drier climate.
Hidden Fastener Systems
Hidden fastener clips give a cleaner surface with no exposed screw heads for water to sit on, and they reduce the number of penetration points into the board itself — fewer entry points for moisture, fewer corrosion-prone fasteners exposed to salt air.
Picture-Framing and Edge Detail
Cut composite board ends are more vulnerable to moisture intake than the capped face and edges. A picture-frame border, proper end-cap treatment, or manufacturer-approved edge trim protects those exposed cuts and gives the deck a finished look at the same time.
Our Process From Estimate to Finished Deck
1. On-Site Assessment
We walk the site, check the existing structure if there is one, look at drainage, sun exposure, and shading patterns that affect moss growth, and talk through how you actually plan to use the space.
2. Material and Layout Selection
We go over composite board options, colors, and board patterns based on your home, your budget, and how much direct rain and shade the deck location gets.
3. Permitting and Structural Plan
Decks over a certain height or attached to the home typically require a permit in Whatcom County jurisdictions. We handle the structural planning to match both code and the composite manufacturer's installation requirements.
4. Framing and Structural Build
This is where the flashing, joist spacing, and drainage decisions get built in — the part of the job that doesn't show once the decking is down but determines how the deck performs for the next 20 years.
5. Decking Installation
Boards go down with the fastening system specified for that product, with attention to expansion gaps, since composite material moves with temperature swings more than people expect.
6. Final Walkthrough
We go over the finished deck with you, including what maintenance it actually needs — and what it doesn't.
Choosing the Right Board for a Custer Property
Capped Composite vs. Capped Polymer
Most quality composite decking today is either capped composite (a wood-plastic core with a protective outer shell) or capped polymer (fully synthetic, no wood fiber content). Capped polymer generally handles constant moisture exposure best, since there's no wood fiber core to worry about even if the cap is ever compromised. Capped composite is often more budget-friendly and performs well for most residential applications when installed correctly.
Color and Heat Considerations
Darker board colors absorb more heat and can be uncomfortable underfoot on sunny days, but they also tend to show less visible staining from organic buildup between cleanings. Lighter and mid-tone colors run cooler but show dirt and moss shadowing more readily if the deck isn't cleaned on a regular schedule. We'll talk through this trade-off based on where your deck sits and how much sun it gets.
Grain Pattern and Board Width
Wider boards mean fewer seams, which can mean fewer places for debris to collect, while textured, low-sheen finishes tend to hide the fine surface film that develops between cleanings better than smooth, glossy finishes do.
Maintaining a Composite Deck in a Moss-Prone Climate
Composite decking is genuinely low-maintenance compared to wood, but "low-maintenance" doesn't mean "no maintenance" — especially here. A simple seasonal routine keeps a composite deck looking like new:
- Sweep debris off regularly, especially fallen leaves and needles that trap moisture against the board surface
- Wash the deck with soap and water (or a manufacturer-approved composite cleaner) at least twice a year — more often in shaded areas
- Keep gutters and downspouts near the deck clear so runoff isn't dumping directly onto the surface
- Trim back overhanging branches and vegetation to reduce shade and improve airflow
- Check and clear any debris buildup underneath the deck where drainage happens
- Address any moss or algae film as soon as it appears rather than letting it establish — it's far easier to remove early
- Avoid pressure washing at close range or high pressure, which can damage the board's protective cap
Why Hire a Crew That Already Works in Custer
A lot of deck problems around here don't come from bad materials — they come from a build that was designed for a different climate. Framing spec'd for a drier region, drainage details that work fine somewhere with less rain, or a lack of attention to how much shade a particular lot gets can all shorten a deck's life regardless of how good the decking material itself is.
Working regularly in Custer and the surrounding Lynden area means we're not guessing at how local conditions affect a build — we're accounting for salt air, rain patterns, and moss exposure as a baseline, not an afterthought. We're also familiar with the permitting expectations in Whatcom County, which keeps the project moving instead of stalling on paperwork.
Get a Free Estimate for Your Custer Deck Project
If you're planning a new composite deck or replacing an aging wood deck in Custer, we're happy to come take a look, talk through material options, and put together a straightforward estimate — no pressure, no hard sell. Use the form below to get started.