Glenhaven Siding Why Composite Decking Fits Deming's Climate
Deming sits in a stretch of Whatcom County where the weather doesn't do decks any favors. Driving rain comes through for months at a time, humidity lingers under tree cover and along the river valley, and moss finds a foothold on almost anything that stays damp and shaded long enough. Add in the salt air that reaches inland on a windy day, and you've got a combination that's hard on wood fibers, hard on fasteners, and hard on finishes.
Composite decking was built for exactly this kind of punishment. It doesn't absorb water the way wood does, so it isn't feeding the moss and mildew the way a damp cedar or fir board will. It won't warp, cup, or split from repeated wet-dry cycles the way natural wood can after a few Whatcom County winters. That doesn't mean composite is maintenance-free, or that every composite deck installed around here holds up the same way — it comes down to the board you choose and how the deck underneath it is built.
Composite vs. Wood: An Honest Comparison for This Climate
We install both wood and composite decking, and we'll tell homeowners honestly which one fits their situation. For a lot of Deming properties — shaded lots, sites close to the river, decks that catch heavy runoff off a roofline — composite is the lower-maintenance, longer-term choice. Here's how the two compare on the factors that actually matter in this climate:
| Factor | Pressure-Treated Wood | Composite Decking |
|---|---|---|
| Moisture absorption | Absorbs water, swells and shrinks seasonally | Minimal absorption; capped boards shed water |
| Moss and algae growth | Common in shaded, damp spots without upkeep | Slower to take hold; still needs occasional cleaning |
| Refinishing needs | Sealing or staining every 1-3 years | None required |
| Splintering or splitting | Increases with age and weather cycling | Doesn't splinter |
| Upfront material cost | Lower | Higher |
| Typical service life here | Shorter without consistent upkeep | Longer with minimal upkeep |
Wood still has a place. It's less expensive up front, and some homeowners like the look and don't mind the maintenance schedule that comes with it. We won't talk anyone out of a wood deck if that's what fits their budget or style. But for anyone tired of re-sealing a deck every couple of springs or scrubbing moss off it every fall, composite is the more honest long-term answer for a wet climate like ours.
What a Correct Composite Deck Installation Involves
Composite boards are only as good as what's underneath them. Most of the deck failures we get called to inspect aren't actually a problem with the decking material itself — they're a framing, fastening, or drainage mistake made during the original build.
Substructure and Framing
Composite is heavier than wood and behaves differently under load and temperature swings, so joist spacing needs to match the manufacturer's span tables for composite specifically, not just whatever spacing worked fine for a wood deck. We also run joist tape or an equivalent barrier along the top of the framing lumber, since trapped moisture between a joist and a fastener is one of the more common causes of hidden rot on decks in wet climates like this one.
Fasteners, Flashing, and Ledger Boards
The ledger board — where the deck attaches to the house — is the single most important detail on any deck, wood or composite. It needs proper flashing to keep water from working its way behind the siding and into the wall framing. We see this done wrong more than any other single item on decks we're asked to repair or rebuild. Fasteners matter too: composite decking requires corrosion-resistant, manufacturer-approved screws or a hidden fastener system rated for composite, not whatever deck screws happen to be sitting in the truck.
Airflow and Drainage Underneath
A deck built low to the ground, or set against a shaded slope, needs a way for air to move underneath it and for water to drain away instead of pooling. Without that, you get a damp microclimate under the deck that stays wet long after a storm has passed — exactly the kind of spot where moss, mildew, and rot get started, even under boards that themselves resist moisture.
Our Process, Start to Finish
Site Visit and Assessment
We start by looking at the site itself — sun exposure, shade from trees, drainage patterns, how close the deck sits to grade, and the condition of anything already there. That tells us what the deck actually needs, not just what was originally asked for over the phone.
Permits and Local Code
Many deck projects — especially ones attached to the house or built above a certain height — need a building permit through the county before work starts. We handle that process as part of the job so homeowners don't have to track it down themselves, and so the finished deck is built to code, not just to look.
Tear-Off or New Build
If we're replacing an existing deck, we pull the old decking and inspect the framing before deciding what stays and what gets rebuilt. We won't cover rotted joists or a bad ledger connection with new composite boards — that just hides a problem under a more expensive material.
Installation and Final Walkthrough
Framing gets corrected or built to span table, ledger flashing goes in properly, joist tape goes down, and composite boards get installed with the fastening system that manufacturer specifies. We keep gap spacing consistent for drainage and expansion, since composite still moves with temperature even though it doesn't absorb water like wood does. Before we call the job done, we walk the deck with the homeowner, check fastener lines, railing attachment points, and stair details, and go over basic care so the deck holds up the way it's supposed to.
Common Problems We Find on Existing Decks Around Deming
Because we work regularly in Deming and the surrounding parts of Glenhaven, we see the same handful of issues repeatedly when we're called out to look at an older deck:
- Ledger boards flashed poorly or not at all, letting water into the rim joist and wall framing
- Joists installed at wood-deck spacing under composite boards, causing bounce or sag over time
- No gap or airflow between the deck and the ground on shaded, low-clearance builds
- Standard deck screws used instead of composite-rated fasteners, leading to staining or loosening
- Moss and organic debris packed into board gaps, holding moisture against the underside
None of these are unusual, and they're rarely the homeowner's fault — they're the result of a deck built to a generic standard instead of one built for a wet, moss-prone climate. It's a big part of why we inspect the existing structure closely before quoting a straight board replacement, rather than assuming what's underneath is sound.
Keeping Your Composite Deck Looking Good Year-Round
Composite cuts down on maintenance, it doesn't eliminate it. A little seasonal attention goes a long way given how much rain and shade a lot of Deming properties deal with over the course of a year:
- Sweep debris out of board gaps before fall rains set in, so leaves and needles don't hold moisture against the boards
- Rinse the deck surface a few times a year to clear pollen, dirt, and early moss growth before it takes hold
- Use a soft-bristle brush and a cleaner made for composite — pressure washing on the wrong setting can scar the surface
- Check railing posts and stair connections annually for movement, especially after a hard winter
- Trim back overhanging branches and brush that keep the deck surface shaded and damp longer than it needs to be
Choosing the Right Composite Board for Your Deck
Not all composite decking is built the same way, and the differences matter more in a climate like ours than they would somewhere dry. Fully capped composite boards — with a protective shell wrapped around the core — hold up better against moisture and staining than older-style uncapped composite, which can absorb some water at the core over time. PVC and PVC-composite hybrid boards go a step further on moisture resistance, generally at a higher price point.
We'll walk homeowners through what's actually appropriate for their specific site — a sunny, open deck doesn't need the same spec as one that sits heavily shaded near tree cover. We'd rather put someone in a mid-range board that's genuinely suited to their site than upsell a premium product they don't need, or undersell a cheap board that won't hold up under this much rain and moss pressure over the years.
Why It Matters That We Already Work in Deming
A deck crew that only shows up once doesn't learn how a specific site behaves through a full Whatcom County year — which side of the house holds shade into the afternoon, where water actually runs off after a heavy rain, how fast moss comes back on a north-facing rail. Working regularly in and around Deming and Glenhaven means we've already seen how local conditions treat decks over multiple seasons, not just on install day.
That local experience shapes real decisions on the job: where we add extra flashing even when it's not strictly required, what board gap spacing makes sense given how much rain this area gets, and where we tell a homeowner that a low-clearance design needs a drainage fix before decking goes down at all. It's the difference between a deck built to a spec sheet and one built for the actual conditions it's going to sit in, season after season.
If you're planning a new composite deck in Deming, or replacing one that hasn't held up the way it should, we're happy to take a look and give you a straight, no-pressure estimate — including an honest read on whether composite is the right call for your specific site. Use the form below to get started.