Bellingham Cemplank Is a Real Fiber Cement Product — Here's Why We Still Don't Install It
Homeowners in Bellingham sometimes ask us to quote a job using Cemplank fiber cement siding because a neighbor has it, a general contractor recommended it, or it showed up cheaper on another bid. We want to be upfront: Cemplank is a legitimate fiber cement product. It's noncombustible, resists rot and insects better than wood, and holds paint better than vinyl. We're not going to tell you it's junk, because that wouldn't be honest.
What we will tell you is why, after years of installing and standing behind fiber cement siding on homes throughout Whatcom County, our company made James Hardie the only fiber cement brand we install. The reasons come down to factory finish, climate-specific engineering, warranty structure, and long-term support — all things that matter more here than they would in a drier, milder region.
Where the Two Products Actually Overlap
Before getting into the differences, it's worth being fair about the similarities. Both Cemplank and James Hardie siding are made primarily from Portland cement, sand, and cellulose fiber. Both are:
- Noncombustible, which matters for insurance and wildfire-adjacent building codes
- Resistant to termites and carpenter ants, unlike wood siding
- Dimensionally stable compared to wood, so they don't swell and shrink the way cedar or primed spruce does
- Rated to hold paint far longer than vinyl before it chalks, fades, or cracks
If your only comparison is fiber cement versus vinyl or wood, both brands are a step up. The differences that matter show up once you start comparing fiber cement products against each other — and against the specific demands of a marine climate like ours.
The Factory Finish Question
This is the biggest practical difference, and the one that drives most of our concern. James Hardie's ColorPlus siding comes from the factory with a baked-on, multi-coat finish applied and cured under controlled conditions before it ever reaches a jobsite. That finish is engineered specifically to resist UV fading and to shed moisture at the surface rather than absorb it at cut edges and fastener points.
A large share of Cemplank siding is sold primed only, which means the actual top coat gets applied on site, by whichever painting crew and whatever weather window is available. Field-applied paint can be a perfectly good coating when it's done right — but "done right" depends on humidity, temperature, dry time between coats, and the skill of whoever's holding the sprayer. In Bellingham, where we get long stretches of drizzle, fog off Bellingham Bay, and a genuine moss season, those application windows are narrower and less forgiving than in drier parts of the country. A factory-cured finish removes that variable entirely.
Why This Matters More Here Than Elsewhere
Salt air off the Sound, driving rain during winter storms, and months of damp shade under evergreen canopy all accelerate wear on any exterior finish that isn't fully cured before installation. A field-painted product that gets rained on two days after application, or installed during a cool snap that slows curing, can end up with a finish that fails years earlier than it should — and that failure usually shows up as chalking, streaking, or peeling right at the seams and fastener heads, which are exactly the spots most exposed to wind-driven rain.
Climate-Engineered Formulations
James Hardie engineers its siding in different formulations for different climate zones — HZ5 for the colder, wetter regions like the Pacific Northwest, and HZ10 for hot, humid Southern climates. The cement formulation, moisture resistance, and freeze-thaw performance are tuned to the region the siding is actually going to be installed in.
To our knowledge, Cemplank does not offer that same level of region-specific engineering across its product line. That doesn't make it defective — plenty of fiber cement performs adequately in moderate climates — but it does mean you're installing a more generic product on a house that faces genuinely un-generic weather: 30+ inches of annual rainfall, salt-laden air near the water, and enough shaded moisture to grow moss on a roof in two seasons flat.
| Factor | James Hardie (HZ5) | Cemplank (general market) |
|---|---|---|
| Regional climate engineering | Formulated specifically for Pacific Northwest moisture and freeze-thaw cycles | General-market formulation, not region-specific |
| Factory finish | ColorPlus baked-on, multi-coat, UV and moisture engineered | Commonly sold primed; top coat applied in the field |
| Local product/color matching for future repairs | Widely stocked in the region; colors and profiles easy to match years later | Availability and long-term color matching vary by distributor |
| Manufacturer warranty on finish | Separate, long-term written warranty on the factory finish itself | Warranty typically covers the substrate; finish is often the painter's responsibility |
Warranty Structure — Read the Fine Print
Every fiber cement manufacturer offers a warranty, and every warranty sounds reassuring in a sales brochure. The detail that actually matters is what the warranty covers and who's responsible for what. James Hardie backs both the substrate (the board itself) and, on ColorPlus products, the factory finish, with terms that are transferable to a new owner if you sell the home. That transferability matters in a market where siding is often a selling point.
With a primed product that's field-painted, the manufacturer's warranty generally stops at the substrate. The paint job — the part most likely to show wear first in our climate — is typically covered by whatever warranty the painting contractor offers, which is usually shorter, harder to enforce years later, and not tied to the siding manufacturer at all. If that contractor is no longer in business by the time a problem shows up, you're on your own.
Installation Sensitivity and Local Support
Fiber cement siding is not a forgiving product to install poorly. Fastener placement, gapping, flashing details, and caulk joints all affect how the product performs over 20-plus years, not just how it looks on install day. James Hardie runs a formal contractor training and certification program, and the company backs installations with published, publicly available installation specifications for our specific climate zone.
That matters practically: when we're troubleshooting a flashing detail on a bay window in a Fairhaven bungalow or figuring out the right clearance above a deck ledger board in the county, we're working from a manufacturer spec sheet built for HZ5 conditions, not general guidance. That level of documented, regionally relevant installation support isn't something every fiber cement brand offers to the same degree.
The Long-Term Cost of Ownership
A lower material cost up front doesn't always mean lower cost over the life of the siding. Over 20 to 30 years, the maintenance burden of a field-painted product usually includes:
- Repainting the entire house on a cycle of roughly 7-12 years, sooner in shaded, damp exposures common in Whatcom County
- Higher risk of moisture intrusion at joints and fastener heads if the field-applied coating fails early
- More difficulty matching color and sheen on partial repairs or additions years after the original install
- Moss and mildew cleaning that's harder on a coating that's already thinner or less UV-stable than a factory finish
A factory-finished product doesn't eliminate maintenance — nothing on a Pacific Northwest exterior is maintenance-free — but it shifts the first repaint cycle out considerably further, which is real money saved over the life of the siding.
Why We Standardized on James Hardie
We made the decision to install James Hardie exclusively because it lets us stand behind a single, consistent system: a climate-matched formulation, a factory finish that removes field-painting weather risk, a warranty structure that covers both substrate and finish, and manufacturer-backed installation specs we can point to if a question ever comes up. When we tell a Bellingham homeowner their siding is built for this climate, we want that to be something we can actually document — not just a sales line.
That's also why we don't install LP SmartSide, vinyl, Allura, primed spruce, or cedar. Each of those has its own set of trade-offs, but the common thread is the same: we'd rather install fewer products well than a wider range of products with maintenance and warranty gaps we'd have to explain to a homeowner five or ten years down the road.
Questions Worth Asking Any Contractor Quoting Fiber Cement
Whether you end up going with us or someone else, these are worth asking before you sign a contract:
- Is this product factory-finished, or will it be primed and painted on site?
- What does the manufacturer's warranty actually cover — substrate only, or substrate and finish?
- Is this formulation rated for this specific climate zone, or is it a general nationwide product?
- Is the installer certified or trained by the manufacturer on this specific product line?
- How easily can this exact product and color be matched for a repair five or ten years from now?
Straight answers to those five questions will tell you more about a siding job's long-term durability than the brochure will.
If you're planning a siding project in Bellingham or anywhere in Whatcom County, we're happy to walk your home, talk through what James Hardie's HZ5 products would look like on your house, and give you a free, no-pressure estimate.