Lynden Exterior What Kendall's Climate Actually Does to Siding
Kendall sits in the stretch of Whatcom County where the marine air pushing in off the Salish Sea meets the rise toward the foothills. That combination means long stretches of damp weather, driving rain that comes in sideways during winter storms, and a moss season that can run eight or nine months of the year on north-facing walls and anything shaded by fir or cedar trees. Homes here don't fail because of one bad storm. They fail slowly, from siding that never gets a real chance to dry out between rain events.
Salt-laden air moving inland accelerates corrosion on fasteners, trim flashing, and any exposed metal detailing. Combine that with constant moisture and you get the two things that ruin most siding jobs in this part of the county: water finding its way behind the cladding, and organic growth breaking down whatever's on the surface. A siding product and installation method that works fine in a dry inland climate can fall apart here in a fraction of the time.
Why We Only Install James Hardie in This Area
Lynden Exterior Co. installs James Hardie fiber cement siding exclusively. We don't offer vinyl, LP SmartSide, Cemplank, Allura, primed spruce, or cedar, and that's a deliberate call based on what we see holding up on Whatcom County homes and what we see failing. Fiber cement is fundamentally different from wood-based or vinyl products: it's made from cement, sand, and cellulose fibers, so it doesn't feed mold the way wood-based siding can, and it doesn't warp, expand, or contract the way vinyl does when temperatures swing.
That doesn't mean every fiber cement product performs the same. What sets James Hardie apart for a climate like Kendall's is that the company engineers specific product formulations for specific climate zones, and it backs the product with a factory finish designed to survive years of exactly the conditions we get here — not a generic all-climate compromise.
Built for the Pacific Northwest Specifically
James Hardie's HZ5 product line is engineered for climates with significant moisture exposure and freeze-thaw cycling, which describes most of western Washington. It's a different formulation than the HZ10 line built for hot, humid, termite-prone regions of the country. When we spec a Kendall job, we're using the version of the product that was actually built for this weather, not a one-size-fits-all board.
The ColorPlus Factory Finish Advantage
One of the biggest points of failure on older siding jobs — of any material — is the paint. Field-applied paint on siding has to bond to a cut, textured surface on site, often in less-than-ideal weather, and it starts weathering from day one. James Hardie's ColorPlus finish is baked on in a factory under controlled conditions, cured to the substrate, and backed by its own dedicated finish warranty separate from the product warranty. In a climate that gets this much sustained moisture and UV cycling, the difference between a factory-cured finish and a job-site paint job shows up within a few years, not a few decades.
For homeowners in Kendall specifically, that matters because repainting siding on a home surrounded by trees and damp shade is an expensive, recurring cost. A finish that's engineered to resist fade and moisture intrusion from the start reduces how often you're back up on a ladder or writing a check to a painting crew.
What a Correct Installation Actually Involves
Fiber cement siding is only as good as the installation behind it. Most of the siding failures we get called out to inspect in this area aren't product failures — they're installation shortcuts that let water get where it shouldn't. A correct James Hardie install on a Kendall home includes:
- A drainable weather-resistive barrier installed with proper lapping, sealed at every penetration
- Rainscreen or furring strip application where wall assembly and exposure call for it, to let the wall cavity actually dry
- Correct fastener type, spacing, and depth — over-driven or under-driven nails are one of the most common causes of early failure and are easy for an inexperienced crew to get wrong
- Proper flashing at every window, door, and roof-to-wall intersection, with kick-out flashing where a roofline meets a sidewall
- Manufacturer-specified clearances from grade, roof lines, decks, and other siding terminations so water has somewhere to go
- Factory-mitered or properly caulked joints using a sealant rated for the exposure, not just whatever's on the truck
None of this is exotic. It's James Hardie's own published installation standard. The problem is that skipping steps doesn't show up on day one — it shows up in year four or five, after moisture has had time to work behind the cladding. That's exactly the kind of slow failure that Kendall's wet, shaded conditions accelerate.
How Our Process Works on a Kendall Job
1. On-Site Assessment
We walk the property, check the current wall assembly, look for existing moisture damage or rot at trim and penetrations, and note site-specific issues like tree cover, north-facing shade walls, and drainage around the foundation — all things that matter more in Kendall's setting than they would on an open, sunny lot.
2. Product and Color Selection
We help you choose the right Hardie board profile (lap siding, shingle-style panels, or a mix with trim accents) and a ColorPlus color that fits the home and holds up to this climate's UV and moisture exposure.
3. Tear-Off and Wall Prep
We remove the old siding, inspect the sheathing for hidden damage, repair or replace anything compromised, and install a correctly lapped weather-resistive barrier and rainscreen gap before a single piece of new siding goes up.
4. Installation to Manufacturer Spec
Fastening, flashing, and clearances are done to James Hardie's published requirements — not shortcuts to save a day of labor. This is the step that determines whether the siding lasts 10 years or 40.
5. Final Walkthrough
We walk the finished job with you, check caulking and trim details up close, and make sure everything meets the standard we'd want on our own home.
Cost Factors to Understand Before You Budget
Every home is different, but the factors that move the price on a Kendall siding job are fairly consistent. Rather than quote a number that won't match your house, here's what actually drives cost:
| Factor | Why It Matters Here |
|---|---|
| Wall assembly condition | Hidden rot from years of moisture exposure adds repair scope before new siding can go on |
| Home complexity | Dormers, multiple rooflines, and cut-up wall shapes mean more flashing and labor |
| Siding profile chosen | Shingle-style panels and mixed-material accents cost more than straight lap siding |
| Rainscreen requirement | Shaded, damp walls benefit most from a drainage gap, which adds a labor step |
| Trim and detail work | Corner boards, window trim, and fascia detailing affect both material and labor time |
| Access and site conditions | Tree cover, slope, and staging space around the home affect crew efficiency |
We provide a written, itemized estimate before any work starts, so you know exactly what you're paying for and why.
Living With James Hardie Siding in a Wet Climate
Fiber cement is low-maintenance compared to wood or vinyl, but "low-maintenance" doesn't mean "zero-maintenance," especially somewhere as damp as Kendall. A simple annual routine keeps the siding performing the way it's designed to:
- Rinse the siding once a year to remove moss spores, pollen, and organic buildup before it takes hold, especially on shaded and north-facing walls
- Keep gutters clear so overflow doesn't run down the face of the siding
- Trim back tree limbs and shrubs that keep a wall section damp and shaded longer than the rest of the house
- Inspect caulking at trim joints and penetrations every couple of years and re-seal where it's cracked or pulled away
- Check that soil, mulch, or deck framing hasn't crept up to meet the bottom edge of the siding, which traps moisture against the board
None of this requires a professional visit every year — it's the kind of upkeep any homeowner can do in an afternoon, and it goes a long way toward getting the full lifespan out of the product.
Why the Installer Matters as Much as the Product
James Hardie is a strong product, but the transferable warranty and the real-world performance both depend on correct installation. A crew that mainly works drier, less exposed parts of the county may not think twice about skipping a rainscreen gap or using a generic sealant instead of one rated for constant moisture. A crew that regularly works Whatcom County's wetter, shadier neighborhoods treats those details as non-negotiable, because we've seen what happens when they're skipped.
Working in and around Lynden and communities like Kendall also means we're not guessing at conditions — we know which wall orientations hold moisture longest, where moss takes hold first, and how the local rain patterns stress a home's exterior over a full year, not just the dry months.
If you're planning a siding project in Kendall, we'll walk your home, give you a straight assessment of what it needs, and put together a written estimate — no pressure, no obligation.