Orcas Island Siding What Cemplank Is, and Why Homeowners Ask About It
Cemplank is a fiber cement siding product, and if you've been pricing out siding on Orcas Island you've probably seen it mentioned alongside James Hardie as a "cheaper alternative that's basically the same thing." At a glance, that's a fair impression. Both are cement-based composite siding made from a mix of Portland cement, sand, and cellulose fiber. Both are non-combustible, both resist rot in a way that wood never will, and both hold paint or factory finish better than vinyl. We're not going to tell you Cemplank is a bad product built by bad people. It's a legitimate fiber cement siding that plenty of contractors install successfully across the country.
What we will tell you is why our crew, working exclusively on Orcas Island and the rest of San Juan County, made the call years ago to install only James Hardie and to turn down every job where a homeowner insists on Cemplank. That decision isn't about brand loyalty for its own sake. It comes down to manufacturing consistency, product support in our specific marine climate, and what happens ten and twenty years down the road when the island's salt air and driving rain have had time to work on a wall assembly.
The Core Problem: Manufacturing and Supply Consistency
Fiber cement is a manufactured composite, not a natural material, which means its long-term performance depends heavily on how consistently it's made batch to batch. James Hardie has owned the largest share of the North American fiber cement market for decades and has invested heavily in plant-level quality control and climate-specific engineering. Cemplank, by contrast, has changed ownership and manufacturing arrangements more than once over the years, and its regional availability and product lineup have shifted along with those changes.
For a contractor, that matters in a very practical way: if we install a product today and a homeowner calls us in twelve years needing a few replacement boards after storm damage, we need to know that product, or a close match to it, will still be manufactured and distributed. On an island, where every material delivery already means a ferry schedule and lead time, we're not willing to bet a client's siding job on a product line that might not exist in its current form a decade from now.
Why This Matters More Here Than on the Mainland
A mainland contractor near a major distribution hub can often source a close-enough match for a discontinued siding profile without much trouble. On Orcas Island, sourcing anything means barging it over, and matching a discontinued board's exposure, texture, and thickness exactly is often impossible. We'd rather build with a product we're confident will still be on the shelf, in the same form, when a homeowner needs a repair.
Salt Air and Coastal Exposure
Orcas Island sits right in the Salish Sea, and homes here, especially anything near Eastsound, West Sound, or the shoreline roads, deal with salt-laden air more or less constantly. Salt air is corrosive to fasteners, aggressive toward coatings, and it accelerates the breakdown of any finish that isn't formulated to resist it. This is one of the biggest factors in our siding decision, because the factory finish on a fiber cement board is doing most of the work of keeping moisture and salt off the substrate underneath.
James Hardie's ColorPlus finish is baked on in a controlled factory environment through multiple coats, and it carries a specific finish warranty separate from the substrate warranty. Cemplank's factory-finish options and warranty structure have historically been less consistent across its product history, which puts more of the long-term coating performance on the shoulders of whichever painter or crew handled field application, if the boards weren't factory-finished at all. In a climate where the finish is your first line of defense against salt exposure, we don't want that variable in play.
Driving Rain and Moisture Management
San Juan County doesn't get the rainfall totals of Seattle or the Olympic Peninsula, but Orcas Island does get plenty of wind-driven rain off the water, and that horizontal rain finds every weak point in a wall assembly that vertical rain would never reach. Fiber cement in general handles moisture better than wood or engineered wood siding, but installation detailing, specifically how water is shed at butt joints, corners, and around penetrations, is what actually determines whether a home stays dry.
This is where product-specific installation guidance matters. James Hardie publishes detailed, climate-zone-specific installation instructions and backs them with training programs for contractors. Getting those details right at butt joints and flashing points is what keeps water from working behind the siding over the years, which is exactly the failure mode that turns into hidden rot on a rain-exposed island home.
Where Installation Sensitivity Shows Up
- Butt joint sealing and shadow-line consistency over time
- Flashing integration at windows, doors, and deck ledgers
- Minimum clearance from grade, decks, and roof lines
- Fastener placement and depth, which affects both water intrusion and finish cracking
- Starter strip and bottom-course detailing at the foundation line
Moss, Shade, and the Long Wet Season
Orcas Island's tree cover and long stretch of overcast, damp months from fall through spring create ideal conditions for moss and algae growth on north-facing and shaded walls. This isn't unique to any one siding brand, fiber cement in general resists the kind of rot moss retention can cause on wood siding, but the surface texture and finish quality of the board affect how much moss and grime actually cling to it and how easy the wall is to clean without damaging the finish.
A dense, well-sealed factory finish sheds more of that biological growth and holds up better to the occasional gentle wash a homeowner might do to keep a shaded wall looking clean. We've found factory finish quality and consistency, again, tends to track with manufacturing investment, which is part of why this keeps coming back to the same conclusion for us.
Warranty Structure: Read the Fine Print
Every fiber cement manufacturer offers some form of warranty, but the structure and transferability of those warranties differ in ways that matter to a homeowner who might sell the house someday. A warranty that's difficult to transfer, or that has a shorter finish warranty nested inside a longer substrate warranty, can leave a future owner with less coverage than the original buyer thought they had.
| Factor | What to Ask About | Why It Matters on Orcas Island |
|---|---|---|
| Substrate warranty length | Years covered and what voids it | Determines coverage against cracking, delamination over decades of wet-dry cycling |
| Finish warranty length | Separate from substrate coverage? | Salt air and UV are hardest on the finish coat specifically |
| Transferability | Automatic or requires paperwork/fee | Island homes turn over; a clean transfer protects resale value |
| Manufacturer stability | How long has the company made this exact product | Affects whether claims will still be honored in 15-20 years |
| Regional product engineering | Is there a climate-specific version | Marine, wet-belt climates need different moisture engineering than dry climates |
Climate-Engineered Product Lines
One of the specific reasons we standardized on James Hardie is its HZ5 product line, engineered for regions with freeze-thaw cycling and prolonged moisture exposure, which describes San Juan County's climate reasonably well even though our winters are milder than inland Washington. Having a manufacturer that engineers distinct product formulations for different climate zones tells us they've done the underlying research on how their material behaves under specific moisture and temperature conditions, rather than selling a single national formulation everywhere.
We haven't seen the same depth of regional climate engineering documented across Cemplank's product history. That's not necessarily a knock on the physical board, it's a statement about how much climate-specific technical backing stands behind it, which is something we want in hand before we put our name on an installation.
What We Actually Install Instead
We install James Hardie fiber cement exclusively, in the HardiePlank lap siding, HardiePanel, and HardieShingle lines depending on the home's style, with ColorPlus factory finish so the color and coating are baked on before the boards ever reach the island. It's a non-combustible material, which matters given how dry our summers can get despite the wet reputation the San Juans have the rest of the year, and it's backed by a transferable warranty structure we can explain clearly to every homeowner before work starts, not after.
This isn't about upselling. Fiber cement siding, installed correctly, is a job you should only have to do once in a homeowner's lifetime on this island. We'd rather turn down a Cemplank install than cut corners on the material that protects a house from salt air, driving rain, and a moss season that doesn't really end.
Questions Worth Asking Any Siding Contractor
- Which specific fiber cement product line, and is it factory-finished or field-painted?
- What does the warranty cover, and is it transferable to a future homeowner?
- Has this product line been engineered for marine or high-moisture climates specifically?
- Who trained the install crew, and on which manufacturer's installation standards?
- What's the plan for replacement boards if a repair is needed in ten or fifteen years?
If you're weighing siding options for a home on Orcas Island, we're happy to walk through what we'd actually recommend for your house, the exposure it gets, and your budget. Reach out for a free, no-pressure estimate and we'll give you a straight answer, not a sales pitch.