Bellingham Siding If you've priced out fiber cement siding in Bellingham, you've probably run into two names: James Hardie and Cemplank. Both are fiber cement products. Both get installed on homes across Whatcom County every year. And on paper, they can look like interchangeable commodities — cut them a board at a time and they're hard to tell apart in a showroom.
We don't install Cemplank. We haven't for years, and we get asked why often enough that it's worth explaining in detail, rather than just saying "it's not what we use." This is a product comparison, not a takedown. Cemplank is a legitimate fiber cement product manufactured by Elementia (formerly Nichiha's parent company distributed it under different arrangements over the years). It has real strengths. But the reasons we standardized on James Hardie come down to consistency, regional engineering, and what we're willing to warranty our labor against — and Bellingham's climate is exactly the kind of environment where those differences show up.
What Cemplank Gets Right
Fiber cement as a category is a good choice for the Pacific Northwest, full stop. It doesn't rot, it resists pests, it's non-combustible, and it holds paint or factory finish far longer than wood. Cemplank is manufactured to the same general ASTM standards that govern fiber cement performance, and it's typically priced a step below James Hardie, which makes it attractive on tight budgets or large multi-unit projects where every board foot matters.
For a contractor or builder working outside a marine climate, on a budget-driven project, Cemplank can be a reasonable material. We're not going to pretend otherwise. The issue for us isn't that Cemplank is a bad product in the abstract — it's that it doesn't hold up to the specific standard we've decided every home we side needs to meet here in Whatcom County.
Where the Differences Actually Matter: Bellingham's Climate
Bellingham sits on Bellingham Bay, which means salt air is a daily fact of life for a large share of the homes we work on, not an occasional coastal exception. Add in driving rain off the Strait of Georgia, a long wet season that stretches from October through May, and a moss season that can run nearly year-round on north-facing walls and shaded lots — and you have a climate that punishes any weak point in a siding system faster than a drier inland market would.
Salt Air and Fastener Corrosion
Salt-laden air accelerates corrosion on any exposed metal — fasteners, flashing, trim connectors. Fiber cement siding systems are only as good as the fastening and finish system around them. James Hardie's HZ5 product line is specifically engineered for climates with severe moisture exposure, including coastal conditions, and the installation specs that go with it are built around that reality. Cemplank doesn't offer the same tier of climate-specific engineering across its line — it's a more general-purpose product, which is fine in a general-purpose climate. Bellingham isn't one.
Driving Rain and Moisture Cycling
Wind-driven rain off the water pushes moisture into joints, laps, and butt seams far more aggressively than a light inland rain does. Fiber cement itself doesn't absorb water the way wood does, but the finish, the caulking, and the factory edge treatment all determine how well a board sheds water at the seams over 20-30 years of freeze-thaw and wet-dry cycling. This is one of the areas where factory-applied finish quality separates products that look similar off the truck.
Moss and Organic Growth
Whatcom County's shaded, wet conditions are close to ideal for moss and algae growth on siding, especially on north and west exposures under tree cover. A durable factory finish resists organic growth and holds up to the occasional wash-down better than a thinner or less consistent coating. Over a decade-plus timeline, this is one of the more visible differences between a product that still looks sharp and one that's chalking, staining, or showing moss lines around fastener heads.
Factory Finish: The Real Differentiator
The single biggest practical difference between Cemplank and James Hardie, in our experience, isn't the fiber cement substrate itself — it's the factory-applied finish system. James Hardie's ColorPlus finish is a multi-coat, baked-on finish applied and cured under controlled factory conditions, backed by its own dedicated finish warranty separate from the substrate warranty. That finish is engineered to resist fading, chipping, and cracking, and it's formulated with the coastal Pacific Northwest sun-to-rain cycle in mind.
Cemplank offers prefinished options as well, but the finish tier, warranty structure, and consistency from batch to batch have not matched what we've seen from Hardie's ColorPlus system in our own work. When a finish underperforms, the homeowner doesn't see "finish failure" — they see fading, chalking, or peeling paint on siding that's supposed to be a 30-year product. That's a callback we'd rather not have, on a product we can't always source consistently to match an existing job.
Installation Sensitivity
Fiber cement siding is not a forgiving product to install poorly, regardless of brand. Both Cemplank and James Hardie require correct fastener placement, proper clearance from grade and roof lines, correctly lapped joints, and manufacturer-specified caulking or sealant at butt joints and penetrations. Where the two diverge is in the depth and consistency of installation documentation, training programs, and regional guidance available to installers.
James Hardie publishes detailed, climate-specific installation guides (including a Pacific Northwest-specific fastening and clearance spec) and runs a contractor training and certification program that we've built our crews' standards around. That gives us one consistent install methodology across every job, one set of clearance and fastening rules we can train to, and one manufacturer to hold accountable if a product-level issue shows up down the road. Splitting our crews' training and inventory across two fiber cement systems increases the odds of a fastener spec or clearance detail getting crossed between jobs — a risk we'd rather eliminate than manage.
Warranty Structure
This is where the gap becomes most concrete for a homeowner. James Hardie's product warranties are non-prorated for a substantial portion of their term and are transferable to a subsequent homeowner if the house sells — a real factor in resale value on a 30-year siding decision. Warranty coverage and transferability on Cemplank product lines have historically been less standardized and, in our experience, less generous in the years that matter most if something does go wrong.
We also warranty our own labor, and we can only stand behind an installation as strongly as the manufacturer stands behind the material underneath it. A mismatch between a strong labor warranty and a weaker product warranty just shifts risk onto us — or onto the homeowner — in ways we're not willing to do.
Side-by-Side: What We Weighed
| Factor | Cemplank | James Hardie |
|---|---|---|
| Substrate durability | Fiber cement, ASTM-compliant | Fiber cement, ASTM-compliant, HZ climate-zone engineering |
| Factory finish | Prefinished options available | ColorPlus multi-coat baked finish with separate finish warranty |
| Coastal/marine engineering | General-purpose product line | HZ5 line engineered for high-moisture, coastal exposure |
| Warranty transferability | Varies, less standardized | Transferable to subsequent owner on qualifying products |
| Installer training/documentation | Available, less regionally specific | Region-specific fastening/clearance specs, contractor certification |
| Typical cost | Generally lower | Moderate premium reflecting finish and engineering |
Why We Standardized on One Product
Running one fiber cement system across every job, instead of quoting whichever is cheaper per project, has real advantages that compound over time. Our crews install one fastening spec, one clearance standard, and one caulking protocol, which means fewer mistakes from switching between systems. We can source materials and color-matched trim consistently for repairs or additions years after the original install. And when a homeowner calls with a warranty question, there's one manufacturer and one set of documentation to point to — not a case-by-case answer depending on which product went on which house.
Given Bellingham's salt air, the volume of driving rain we get off the water, and how long moss season really runs here, we decided the climate-specific engineering, finish warranty, and transferability James Hardie offers were worth the standardization. That's a business decision as much as a technical one, and we think it's the honest one to explain rather than bury in a sales pitch.
What This Means If You're Comparing Bids
If another contractor quotes Cemplank at a lower price, that doesn't mean they're cutting corners — it may just reflect a different standard than ours, and for some budgets and some projects, that's a defensible call. What we'd encourage any Whatcom County homeowner to ask, regardless of contractor, is:
- What warranty coverage applies to the siding material itself, and is it transferable if you sell the home?
- Is the finish factory-applied, and what's the separate finish warranty (if any)?
- Is the product line engineered for coastal or high-moisture exposure, or is it a general-purpose spec?
- What fastening and clearance spec will the crew follow, and is it documented by the manufacturer for this region?
- What happens if you need a matching repair or addition in 10 years — can the same product still be sourced?
Those questions matter more than the brand name on the box, and they're the same ones we asked ourselves before we picked a side.
If you're weighing siding options for a home in Bellingham or anywhere in Whatcom County, we're glad to walk through what we install, why, and what it would look like on your specific house. Reach out for a free, no-pressure estimate — there's a form right below this page.