Blaine Siding Cemplank Is Real Fiber Cement — So Why Not Use It?
Cemplank is a legitimate fiber cement siding product, not a vinyl or composite knockoff. It's made from the same basic recipe as most fiber cement: Portland cement, sand, and cellulose fiber, cured into a rigid board that resists fire, rot, and insects far better than wood. On paper, it competes directly with James Hardie. In practice, we stopped specifying it, and the reasons come down to how it's finished, engineered, and supported once it's on a wall in Blaine.
The Factory Finish Gap
The biggest difference isn't the cement board itself — it's what's on top of it. James Hardie's ColorPlus finish is baked on at the factory in multiple coats under controlled conditions, and it carries its own dedicated finish warranty separate from the substrate warranty. A lot of Cemplank product we've encountered ships primed only, meaning the actual color coat gets applied on-site, in the field, by whoever is holding the sprayer that day.
Field-applied paint on fiber cement is workable, but it introduces variables a factory finish avoids: weather conditions during application, coating thickness consistency, and cure time before the siding gets exposed to rain. In a place like Blaine — where driving rain off the Strait of Georgia and a marine layer that lingers for months isn't the exception, it's the norm — we don't want the finish quality of a 30-year siding job resting on how good the weather was during the two weeks it was installed.
Cut Edges and Whatcom County's Moisture Load
Any fiber cement board — Hardie included — needs cut edges and drill points sealed in the field, because factory finish only covers the face and factory-cut edges. That's not unique to Cemplank. But the margin for error matters more in Whatcom County than in drier climates. Between the salt air rolling in off Semiahmoo Bay, the long moss season that keeps north-facing walls damp for weeks at a time, and rainfall that's frequent rather than occasional, an unsealed or poorly sealed edge has more opportunities to wick moisture here than it would somewhere with a real dry season. We'd rather build in less room for that mistake than more, and a factory-finished board with fewer field-touched surfaces does that.
Regional Engineering and Track Record
James Hardie makes climate-specific product lines — HZ5 for regions with freeze-thaw and moisture exposure like ours, HZ10 for hot-humid climates — engineered and tested for those specific conditions. That's a level of regional specificity we haven't seen matched in Cemplank's lineup. Hardie also has decades of installed product in the Pacific Northwest specifically, which means there's a real track record of how it performs against salt air and sustained wet weather, not just general fiber cement performance claims.
Warranty Structure and Who Backs It
Both products carry manufacturer warranties, but the details matter. Hardie's warranty is well-documented, transferable to a new homeowner if the house sells, and backed by a company with a large, established distribution and support network in this region. When we've looked into Cemplank's warranty terms and local support, the coverage has been less consistent and the distribution network thinner in the Pacific Northwest specifically — which matters if a homeowner ever needs a warranty claim processed or matching replacement boards years down the road.
What This Isn't
This isn't a claim that Cemplank is a bad product or that homes sided with it are doomed to fail. Installed correctly, with proper sealing and a competent paint job, fiber cement of any brand will outperform vinyl and most wood siding. Our decision is about consistency and risk management for our own crews and our own warranty commitments — not a verdict on every board Cemplank has ever made.
Why We Standardized on Hardie Instead
We install only James Hardie for one practical reason: it lets us give every homeowner the same answer about what's on their house, backed by the same factory finish, the same climate-matched product line, and the same warranty structure, every time. In a climate that throws salt air, sustained rain, and months of moss growth at exterior walls, we'd rather not introduce field-finish variability into that equation. Hardie's ColorPlus technology, HZ5 engineering, and transferable warranty give us a consistent standard we can stand behind on every job in Blaine and the rest of Whatcom County.
If you're comparing siding options for a home here, we're happy to walk through what Hardie's product lines look like for your specific house and give you a straightforward, no-pressure estimate — just fill out the form below.