Lynden Siding Why Aldergrove Homes Take a Different Kind of Beating
Aldergrove sits in the same weather system as Lynden, just across the border crossing on Guide Meridian/Highway 13, and the exterior of a house here has to deal with three things year-round: salt-laden marine air moving in off the Strait, driving rain that comes sideways during fall and winter storms, and a moss season that can run eight months or longer under the tree cover common to this part of the Fraser Valley. None of that is exotic — it's the normal Pacific Northwest pattern — but it's a lot harder on siding than most homeowners realize until they're dealing with paint failure, soft trim, or green streaking on the north wall.
Siding that's marketed as "good enough" in a drier climate often isn't built for this combination. Salt air accelerates corrosion on fasteners and hardware. Wind-driven rain finds every gap in flashing and caulk. And moss doesn't just look bad — it holds moisture against the wall long after a normal rain would have dried off, which is exactly the condition that rots wood trim and delaminates poor-quality siding products.
What "Correct" James Hardie Installation Actually Means Here
James Hardie fiber cement is the right material for this climate, but the material alone doesn't make a job weatherproof. The installation details matter as much as the product, especially in a wet marine environment. A correct install for an Aldergrove-area home includes:
- A drainage plane behind the siding (house wrap or rainscreen furring) so any moisture that does get past the cladding has somewhere to go instead of sitting against the sheathing
- Properly lapped and sealed flashing at every window, door, and roofline intersection — the spots where wind-driven rain actually gets in
- Correct fastener spacing and type, driven so the head sits flush without crushing the board, which keeps the factory finish intact and the water-shedding lap doing its job
- Caulking only where Hardie's own installation instructions call for it — over-caulking traps moisture just as badly as under-caulking lets it in
- Proper clearance at grade, decks, and patios so siding isn't sitting in standing water or buried in soil or mulch, which is a common moss and rot starting point
Skip any one of these and you can install the best siding on the market and still get moisture problems within a few years. This is where a lot of "siding jobs" go wrong — not the material, the details.
Why the Moss Season Specifically Changes the Job
A long moss season means north- and shade-facing walls stay damp longer between rain events. That doesn't make Hardie siding fail — fiber cement doesn't feed mold or rot the way wood does — but it does mean trim, caulk joints, and any exposed fastener has to be done right the first time, because those are the spots where moss and algae actually get a foothold and where water damage starts if the detail is wrong.
Which James Hardie Product Lines Fit This Area
James Hardie makes several siding profiles, and the right one depends on the home's style and exposure, not just personal preference.
| Product | Best Use | Why It Fits This Climate |
|---|---|---|
| HardiePlank lap siding | Most single-family homes | Traditional lap profile sheds wind-driven rain efficiently; available in ColorPlus factory finish |
| HardiePanel vertical siding | Accent walls, gables, modern builds | Works well paired with board-and-batten trim; needs correct joint detailing in a wet climate |
| HardieShingle | Craftsman and cottage-style homes | Gives a cedar-shake look without the maintenance or moisture absorption of real wood shingle |
| HardieTrim | Corners, fascia, window/door surrounds | Fiber cement trim won't soften or rot the way primed spruce trim does under long damp exposure |
Hardie's HZ5 formulation, engineered for climates with freeze-thaw cycling and heavy moisture, is the appropriate specification for this region. It's not a marketing add-on — it's a real difference in how the board is formulated to hold up in exactly the conditions Aldergrove and Lynden get most winters.
Why We Don't Install Anything Else Here
We get asked fairly often about vinyl, LP SmartSide, cedar, and lower-cost fiber cement alternatives, and it's a fair question — they're all cheaper up front. Here's the honest trade-off for each in this specific climate:
- Vinyl siding is inexpensive and easy to install, but it expands and contracts with temperature swings, can crack in cold snaps, and its seams give wind-driven rain more opportunities to get behind the cladding over time.
- LP SmartSide is an engineered wood product — it performs reasonably well when it's sealed and maintained perfectly, but any cut edge, fastener hole, or caulk failure exposes wood fiber to moisture, and a long moss season doesn't forgive maintenance gaps.
- Cedar and primed wood siding look great when new, but they need repainting and recaulking on a schedule that most homeowners don't keep up with, and damp shaded walls are where wood siding shows rot first.
- Lower-cost fiber cement (Cemplank, Allura, and similar) is a reasonable product category, but we've standardized on James Hardie specifically for its factory ColorPlus finish, its climate-specific HZ engineering, and a warranty structure that's proven to hold up when a job is inspected years later.
None of these are bad products in the abstract. They're just products we don't think hold up as well as Hardie does, given what this climate does to a house over 15-20 years, and we'd rather install one thing correctly than several things at a discount.
How the Job Actually Runs
1. Walkthrough and Assessment
We look at the existing siding, the condition of the sheathing underneath where it's exposed, trim and flashing at windows and rooflines, and any spots showing moss buildup or soft wood — those tell us where moisture has already been getting in.
2. Tear-off and Sheathing Check
Old siding comes off and we check the wall sheathing itself. If there's rot or moisture damage behind the old material — common on north walls with a long moss history — that gets addressed before anything new goes up. Covering damaged sheathing with new siding just hides the problem.
3. Weather Barrier and Rainscreen
House wrap and, where appropriate, rainscreen furring strips go on to create that drainage gap behind the siding — the single biggest factor in how a wall handles driving rain over time.
4. Hardie Installation
Siding, trim, and flashing go in to Hardie's published specifications and local best practice for this climate — correct fastening, correct laps, correct clearances.
5. Final Detail and Walkthrough
Caulk joints, touch-up paint at cut ends (using Hardie's matched touch-up product), and a walkthrough so you know exactly what was done and what the warranty covers.
Cost Factors for an Aldergrove-Area Project
| Factor | Why It Affects Price |
|---|---|
| Tear-off vs. new construction | Removing and disposing of old siding adds labor; new construction or additions skip that step |
| Sheathing condition | Moisture-damaged sheathing found during tear-off needs repair before new siding goes on |
| Home size and stories | More square footage and multi-story walls mean more material and more scaffolding/staging |
| Trim and architectural detail | Gables, dormers, and decorative trim take more labor than a simple rectangular wall |
| Siding profile chosen | HardieShingle and custom accent work generally cost more per square foot than standard lap |
| Access and site conditions | Tight lots, fencing, or landscaping close to the house can add setup time |
We give real numbers after we've actually looked at the house — anyone quoting a firm price over the phone for a job they haven't seen is guessing.
Why a Local Crew Matters More Than It Sounds Like
A crew that already works Lynden and the Aldergrove side of the border knows this specific weather pattern — not a generalized "Pacific Northwest" pattern, but the actual mix of salt air, storm direction, and moss timing that this corridor gets. That shows up in small decisions: when in the season to schedule install so caulk cures properly, how much rainscreen gap to build in for this area's rain volume, and which walls on a typical local floor plan take the worst of the wind-driven rain.
It also matters after the job is done. Warranty service, a caulk touch-up, or a question five years down the road gets answered by a crew that's still working nearby — not a call center for a company that moved on to the next region.
Questions to Ask Before Hiring a Siding Contractor Here
- Do you specify a drainage plane or rainscreen, or just wrap and nail the siding directly to the sheathing?
- What happens if you find moisture damage in the sheathing once the old siding is off?
- Are you a factory-trained or certified James Hardie installer, and can I see that in writing?
- What does the warranty actually cover — material only, or labor too — and who backs it if the installer isn't around in ten years?
- Have you worked in this specific area before, and can you speak to how the local climate affects the install?
If you're in Aldergrove and dealing with tired, moss-streaked, or failing siding, we're glad to come take a look and give you a straight answer on what's going on and what it would take to fix it right. The estimate is free, there's no pressure, and you'll get a real number based on your actual house — just fill out the form below.