What's the actual difference between composite decking and PVC decking?

Composite decking is made from a blend of wood fiber and plastic, while PVC decking is fully synthetic with no wood content. Composite tends to have a more natural wood-grain look and feel underfoot, while PVC is slightly more moisture-resistant and lighter. Both hold up well against the rain and moss common in this region, so the choice usually comes down to look, feel, and budget.

What should I ask a contractor before hiring them for a composite deck in this area?

Ask how they detail ledger flashing where the deck meets the house, what joist spacing they use for composite boards, and whether they're rated or insured to work at your property, including across the border if you're in Aldergrove. Ask to see how they handle drainage and airflow under the deck, since that's where most long-term problems start. A contractor who can answer specifically, rather than generally, has usually done this work before.

Do you install specific composite decking brands, or does it vary by project?

It varies by project and budget — there are several well-established composite manufacturers with different board tiers, colors, and warranty structures. We'll go over the realistic options for your project during the estimate rather than pushing one brand regardless of fit. What matters more than the brand name is the tier of board and how the substructure underneath it is built.

Does composite decking get slippery when wet from all the rain here?

Most modern composite boards have a textured, grooved surface designed to improve grip in wet conditions, which matters given how much of the year this area sees rain. That said, any deck surface can get slippery when moss or algae builds up on top of it, which is why keeping boards clean matters as much as the material choice. Higher-traffic areas and stairs are worth extra attention when choosing board texture.

Can Lynden Siding Replacement build decks for homes in Aldergrove, BC, or only on the U.S. side?

We work with homeowners on both sides of the border given how close Aldergrove is to Lynden, but permitting for your project goes through your local municipality rather than through us. We'll talk through scheduling and material delivery logistics for a cross-border project during the site visit so there are no surprises. The climate and construction approach are similar enough on both sides that the same deck-building fundamentals apply.

Composite Decking in Aldergrove, BC & Lynden, WA

Composite Decking Built for the Aldergrove–Lynden Climate

Aldergrove, BC sits just across the line from Lynden, close enough that plenty of homeowners on the Canadian side end up comparing notes with neighbors in Whatcom County about contractors, materials, and how their outdoor living spaces are holding up. It makes sense — the two communities share the same weather system. Whether your deck footprint is in the Fraser Valley or the Nooksack lowlands south of the border, it's dealing with the same long wet season, the same moss pressure, and the same marine air moving in off the Strait of Georgia and Puget Sound.

That shared climate is exactly why composite decking has become the practical choice for a lot of homeowners in this corridor. Wood decks in this region need constant upkeep to stay ahead of rot and moss. Composite decking, installed correctly, gives you a deck that looks the same in year eight as it did in year one — provided the substructure underneath it was built to actually shed water instead of trap it.

What a Deck Has to Survive Here

Before talking about materials, it helps to be honest about what a deck in this area is up against. This isn't a dry-climate build. It's a wet-climate build with long stretches of low sun angle, and that combination is harder on decking than most homeowners expect.

Rain That Doesn't Let Up

Driving rain here isn't just a fall event — it's a season that runs from October well into spring, with plenty of gray, damp days mixed in through summer. Any decking material that can absorb moisture, or any framing detail that lets water sit instead of drain, is going to show it within a couple of seasons.

Moss That Never Really Goes Dormant

The moss season here is genuinely long. Board surfaces, joist tops, and anywhere debris collects will grow moss and algae if there isn't airflow and drainage to dry things out between rain events. On a wood deck, that moss holds moisture against the boards and accelerates rot. On composite decking, moss is mostly cosmetic and cleanable — but only if the boards were installed with proper gapping and ventilation underneath.

Salt-Laden Marine Air

Homes further inland don't think about salt air, but onshore flow off the Strait of Georgia and Puget Sound pushes moist, mineral-laden air well into the Fraser Valley and Whatcom County lowlands. Over years, that air accelerates corrosion on hardware, fasteners, and metal flashing that wasn't rated for it. It's a slower, quieter problem than moss, but it's one of the more common reasons we find corroded fasteners on decks that are otherwise in decent shape.

Composite Decking vs. Other Deck Materials

We get asked fairly often why we steer most Aldergrove and Lynden clients toward composite over pressure-treated lumber or cedar. It comes down to how each material actually behaves in a wet, moss-prone climate over the long run — not brand preference.

Material	Moisture Behavior	Moss/Algae Resistance	Ongoing Maintenance
Composite decking	Doesn't absorb water into the board itself	Surface growth cleans off; doesn't feed into the material	Occasional wash; no staining or sealing
Pressure-treated lumber	Absorbs and releases moisture seasonally, which drives warping	Growth takes hold in the wood grain and holds moisture against it	Annual cleaning and re-sealing to keep rot at bay
Cedar	More stable than PT lumber but still moisture-permeable	Similar issue to PT lumber, especially in shaded areas	Regular oiling/sealing; sanding as it grays
PVC decking	Fully moisture-resistant	Very good, similar to composite	Low; can look and feel more plastic underfoot

Composite isn't the only reasonable option in this table — PVC decking holds up just as well against moisture and is worth discussing if you want the lowest possible maintenance and don't mind the different look and feel underfoot. Where we don't recommend a product, it's usually about long-term maintenance burden or how forgiving it is to install correctly in wet conditions, not a knock on any manufacturer.

What a Correct Composite Deck Installation Actually Involves

Composite boards themselves are close to maintenance-free, but the deck as a whole is only as good as what's underneath the boards. This is where most of the long-term problems we get called out for actually started — not with the decking material, but with the framing and flashing decisions made before a single board went down.

Ledger Flashing Where the Deck Meets the House

Any deck attached to the house needs proper ledger board flashing that directs water away from the wall structure, not into it. In a climate that sees this much rain, a missed or undersized flashing detail here is one of the more common ways water ends up inside a wall cavity years later.

Joist Spacing and Airflow

Composite boards typically need tighter joist spacing than solid wood decking to prevent sagging, and manufacturers are specific about it. Just as important is leaving enough clearance underneath the joists for air to move — a low, tight crawlspace under a deck traps moisture and speeds up moss growth on the underside of the boards.

Fasteners and Hardware

Given the marine air in this area, hardware matters more here than it would in a drier inland climate. Structural screws, joist hangers, and hidden fastener clips should be rated for exterior, corrosion-prone environments — not just whatever came in the cheapest hardware pack.

Board Gapping

Composite boards need consistent gapping, both for water drainage between boards and to allow for the material's natural expansion and contraction with temperature swings. Too tight, and boards can buckle. Too loose, and you get an uneven, unfinished look.

Our Process for Aldergrove and Lynden Deck Projects

The process itself isn't complicated, but a few steps matter more here than they would somewhere drier.

Site visit and assessment — we look at drainage on the lot, sun exposure, existing framing if it's a tear-off and rebuild, and how the new deck will tie into the house.
Material and layout discussion — board tier, color, railing style, and any stairs or multi-level layout, priced honestly against your budget rather than upsold.
Framing and flashing — the substructure gets built to drain and dry, with flashing detailed at every point the deck contacts the house.
Decking installation — boards installed to spec with correct spacing, fastening, and any picture-framing or pattern work you've chosen.
Final walk-through — we go over basic care so the deck stays looking the way it did the day it was finished.

For homeowners in Aldergrove weighing a Lynden-based crew, it's a fair question to ask how the logistics work across the border — permitting is handled through your local municipality, not ours, and material delivery and scheduling need to account for the crossing. We're upfront about that during the site visit rather than after a quote is signed.

Cost Factors for a Composite Deck

Composite decking costs more upfront than pressure-treated lumber and less than most homeowners assume once they factor in years of staining and sealing avoided. What actually moves the number on a given project is usually one of these:

Factor	Why It Matters
Deck size and shape	Square footage plus cuts around angles, curves, or multiple levels
Board tier	Entry-level composite vs. capped, higher-end lines with deeper color and grain options
Existing substructure condition	Reusing sound framing costs less than a full tear-off and rebuild
Height and stairs	Elevated decks need railing systems and stair stringers that add labor and material
Railing style	Composite, aluminum, or cable railing all price differently
Site access	Tight lots or backyard-only access can add labor time for material staging

We'll walk through where your project lands on each of these during the estimate, rather than quoting a flat per-square-foot number that doesn't reflect your actual site.

Keeping a Composite Deck Looking Right in This Climate

Composite decking is low-maintenance, not no-maintenance, especially with the moss season this area sees. A little seasonal attention goes a long way:

Sweep leaves, needles, and organic debris off the boards regularly, especially in fall — trapped debris holds moisture and feeds moss growth
Clean the gaps between boards a couple of times a year so drainage channels don't clog
Wash the surface with a soft-bristle brush and mild soap and water rather than a pressure washer on high setting, which can damage the board's surface layer
Check ledger flashing and any spots where the deck meets the house once a year for signs of water intrusion
Trim back overhanging vegetation that keeps sections of the deck shaded and slow to dry
Avoid harsh chemical cleaners or de-icers not rated for composite material

Why It Matters That We Already Work in Aldergrove and Lynden

A crew that's never dealt with this specific combination of long moss seasons, driving rain, and marine air tends to learn those lessons on your deck — undersized joist spacing, missed flashing details, hardware that corrodes early. We've built and repaired decks around Whatcom County long enough to know which details actually matter here versus what's fine to simplify. That's the difference between a deck that needs attention every year and one you mostly forget about.

If you're in Aldergrove, BC or Lynden and thinking about a composite deck — new build, replacement, or a rebuild on an aging structure — we're happy to come take a look and give you a straightforward, no-pressure estimate using the form below.