Semiahmoo Siding Cedar siding has a long history on homes along the Semiahmoo Bay shoreline, and it's not hard to see why. Real wood grain, warm color, a look that fits the Pacific Northwest aesthetic people move here for. We get asked about it regularly, and we understand the appeal. But we stopped installing cedar siding, and we think homeowners deserve a straight answer about why before they spend thousands of dollars on a product that will need constant attention in this climate.
This isn't a knock on cedar as a material. Old-growth cedar, properly milled, is genuinely good wood. Our position is about what happens to that wood once it's hung vertically on a wall in a place with salt air, driving rain off the Strait of Georgia, and a moss season that can run eight months out of the year. The gap between how cedar performs in a showroom photo and how it performs on a real Whatcom County exterior after ten winters is the whole reason we made the switch.
What Cedar Gets Right
Fair is fair. Western red cedar is naturally resistant to decay compared to most softwoods, thanks to oils in the wood that slow fungal growth. It takes stain well, it's lightweight and easy to mill into different profiles, and there's a certain warmth to real wood siding that manufactured products spend a lot of marketing budget trying to replicate. If you strip a house down to bare cedar lap siding that's been meticulously maintained, it can look excellent.
The catch is in that phrase: meticulously maintained. Cedar's natural decay resistance buys you time, not immunity. It's a head start, not a finish line. Everything else about how cedar behaves once it's installed works against a homeowner who wants to enjoy their house instead of maintaining it.
The Maintenance Cycle Nobody Mentions at the Sales Pitch
Cedar siding needs to be refinished on a schedule, not "when it starts looking bad." Solid stain typically needs reapplication every 3 to 5 years; semi-transparent stains often need it every 2 to 3 years in a wet marine climate like ours. Skip a cycle and you're not just touching up color — you're letting the wood go bare to moisture and UV, which shortens the life of the boards underneath.
That refinishing isn't a weekend DIY job done right. It means pressure washing (carefully, so you don't blow water behind the boards), letting the wood dry fully — which can take longer than people expect this close to the water — sanding or scraping failed finish, and applying two coats correctly. Multiply that by every wall of the house, on a schedule that repeats for as long as you own the home, and the "lower material cost" of cedar starts looking different once you price in 20 years of upkeep.
Moisture, Moss, and the Semiahmoo Climate Problem
This is the core of it. Semiahmoo sits right on the water, and Whatcom County as a whole sees a long wet season with persistent low-angle sun that doesn't dry surfaces out the way it would further inland. That combination — driving rain, salt-laden air, and shaded north and west-facing walls that stay damp for days — is close to the worst-case environment for painted or stained wood siding.
Wood siding in this environment is prone to:
- Moss and algae growth on any wall that doesn't get regular direct sun, especially under eaves and near landscaping
- Cupping and warping as boards absorb moisture unevenly on the front versus back face
- Checking and splitting as the wood repeatedly swells and shrinks through wet-dry cycles
- Finish failure at butt joints and fastener heads, where water finds its way in first
- Accelerated weathering on walls exposed to salt air off the bay, which can dull and degrade finishes faster than the same product would age further inland
None of this means cedar "fails" in some dramatic way. It's slower and quieter than that — a gradual erosion of the finish, a little more moss every year, boards that start to cup at the edges, until one day the whole exterior needs to be stripped and refinished or replaced outright.
Insects, Woodpeckers, and Rot at the Edges
Wood siding is food and habitat to something, even well-maintained wood. Carpenter ants and other wood-boring insects are drawn to any softened or damp wood, particularly around window trim, corner boards, and anywhere finish has thinned. Woodpeckers are a real nuisance issue on cedar in this region too — they'll drill into siding looking for insects or to establish territory, and repairing that damage means matching old, weathered cedar to new boards, which is never a perfect match.
Rot tends to start in the same predictable spots: butt joints between boards, the bottom edges near grade, and anywhere flashing or caulking has failed. Catching it early requires someone actually inspecting the siding on a regular basis — not just admiring the color from the driveway.
A Straight Look at the Numbers
| Factor | Cedar Lap Siding | James Hardie Fiber Cement |
|---|---|---|
| Refinishing schedule | Every 2-5 years (stain-dependent) | ColorPlus factory finish typically holds 15+ years before repainting is needed |
| Moisture behavior | Absorbs and releases moisture; prone to cupping, splitting, swelling | Engineered to resist moisture-related warping when installed to spec |
| Combustibility | Combustible | Non-combustible core material |
| Pest vulnerability | Attractive to insects and woodpeckers | Not a food or nesting source |
| Moss/algae resistance in wet climates | Low without regular cleaning | Significantly more resistant, especially with factory-cured finish |
| Warranty structure | Varies by installer/finish product; often limited | Manufacturer-backed, transferable product warranty |
The upfront material cost of cedar can look competitive next to fiber cement. It's the total cost over 15 to 20 years — refinishing labor, repair patches, and earlier full replacement — where the comparison changes.
Why We Standardized on James Hardie
We install exclusively James Hardie fiber cement siding, and it's not because it's the only option on the market — it's because after years of doing this work in Whatcom County's climate, it's the product we're comfortable standing behind. Hardie's HZ5 product line is engineered specifically for climates with significant moisture exposure, which describes Semiahmoo about as well as anywhere in the state.
A few specifics that matter for a house near the water:
- Non-combustible core — fiber cement doesn't feed a fire the way wood siding can
- ColorPlus factory finish — baked on in a controlled environment, which holds color and resists fading and moss growth far longer than field-applied stain
- Moisture-engineered composition — built to resist the swell-shrink cycle that causes cupping and cracking in wood
- Strong transferable warranty — backed by the manufacturer, not just the installer's word
Hardie isn't maintenance-free — no exterior product is, especially in a coastal climate. Caulking still needs periodic attention, and it should still be rinsed off occasionally to keep salt residue and organic growth from building up. But the maintenance burden is a fraction of what cedar demands, and the product doesn't degrade structurally the way wood does when that maintenance slips for a season or two.
When Cedar Might Still Make Sense
We're not going to pretend cedar is wrong for every application. Small accent areas, gable details, or a feature wall under a covered porch where it's shielded from direct weather can work reasonably well, because the exposure is limited and the maintenance burden is manageable. It's full-exposure, whole-house cedar siding on a coastal property that we think sets homeowners up for a maintenance cycle they didn't fully sign up for.
What to Ask Before You Choose a Siding Product
- What is the realistic refinishing or repainting interval for this product in a wet, coastal climate — not the manufacturer's best-case number?
- What does the warranty actually cover, and is it backed by the manufacturer or just the installer?
- How does this product handle a wall that stays shaded and damp most of the year?
- What's the total cost over 15-20 years, including maintenance labor, not just the installed price today?
- Is the installer experienced with this specific product's flashing and moisture-management details, since that's where most siding failures actually start?
Talk to Us Before You Decide
If you're planning a siding project in Semiahmoo or anywhere in Whatcom County and cedar is on your list, we're glad to walk through what we've seen it do to homes in this exact climate and explain why James Hardie is what we recommend instead. Reach out for a free, no-pressure estimate — we'll look at your home's specific exposure and give you an honest read on what will hold up.