Anacortes Exterior Two Very Different Materials, One Decision
When homeowners in Anacortes start pricing out new siding, they usually end up comparing two very different products side by side: fiber cement and engineered wood. Both are marketed as upgrades over vinyl. Both come primed or factory-finished, both are sold in lap, panel, and shingle profiles, and both are installed by reputable contractors throughout the Pacific Northwest. But they are not the same material, and they do not behave the same way once they're on a house that faces Rosario Strait or Fidalgo Bay winters.
This page walks through how fiber cement (the James Hardie product line) and engineered wood (most commonly LP SmartSide) are made, how each performs in Skagit County's specific climate, and why we made the decision years ago to install fiber cement exclusively. We're not going to tell you engineered wood is junk — it isn't, and plenty of homes wear it fine in drier climates. We're going to explain the trade-offs as we see them, and why those trade-offs matter more here than almost anywhere else in the state.
How Each Product Is Made
Fiber Cement
Fiber cement siding is a blend of Portland cement, sand, and cellulose fiber, cured under pressure and heat. There's no wood grain structure to it — it's an engineered mineral product shaped to look like wood clapboard, shingle, or panel siding. Because the base material is cement rather than wood, it doesn't have grain to swell along, and it isn't a food source for insects or fungus.
Engineered Wood
Engineered wood siding is made from wood strands or wafers bonded with resins and waxes under heat and pressure, similar in concept to OSB sheathing but formulated and finished for exterior use. Manufacturers treat the panels with zinc borate and coat them to resist moisture and insects. It's still fundamentally a wood product, though — wood fiber held together with adhesive, not a mineral composite.
Moisture: The Real Test in a Salt-Air Climate
Anacortes sits on Fidalgo Island, surrounded by saltwater on three sides, and the weather pattern that defines Skagit County siding performance isn't dramatic storms — it's the steady combination of driving rain off the water, salt-laden air, and a long moss season where surfaces stay damp for months at a stretch. That combination is hard on any exterior material, but it's hardest on anything with wood fiber at its core.
Fiber cement is not organic material. It can get wet and dry out without swelling, delaminating, or rotting, because there's no wood structure to absorb water into. Engineered wood, even with its resin binders and factory coatings, is still made from wood strands. The entire performance of the product depends on the factory coating and the field-applied caulking and paint staying intact at every cut edge, corner, and fastener penetration. Where that seal is compromised — a missed caulk joint, a cut edge left unsealed, a spot where moss holds moisture against the panel for weeks — water can reach the wood fiber underneath, and once it does, swelling and edge deterioration can follow.
In a drier inland climate, a small lapse in caulking might go unnoticed for years. On a house exposed to Rosario Strait weather, with driving rain hitting the same wall for days during a winter system and moss regrowing on north-facing elevations every year, that margin for error shrinks considerably.
Moss and Algae Growth
Skagit County's damp, shaded microclimates are ideal for moss and algae on siding, roofing, decking — pretty much any exterior surface that doesn't get much direct sun. Fiber cement itself doesn't feed organic growth, but moss can still take hold on the surface finish, especially in shaded, low-airflow spots. The difference is what happens underneath. On fiber cement, prolonged moss coverage is a cosmetic and maintenance issue. On engineered wood, prolonged moisture retention at the surface is exactly the condition that stresses the sealed edges and coating the product depends on.
Fire Performance
Fiber cement is noncombustible — it doesn't contribute fuel to a fire, which matters increasingly to insurers and to homeowners paying attention to wildfire-adjacent building codes even on the west side of the Cascades. Engineered wood siding is a wood-based product; it carries a Class A fire rating when manufactured and installed correctly, but it is still, at its core, a combustible material treated and rated to perform well. For homeowners weighing insurance considerations or simply wanting one less combustible material on the exterior of their home, that's a meaningful distinction, not a marketing point.
Finish, Maintenance, and Long-Term Appearance
This is where the two products diverge the most in day-to-day ownership.
James Hardie's ColorPlus finish is baked on at the factory in a controlled environment, with UV-cured coats and a touch-up system for the rare field scratch. It's engineered to hold color for years without repainting, which matters on a house facing salt spray and constant marine humidity — conditions that fade and chalk ordinary paint faster than they do in drier regions.
Engineered wood is typically factory-primed and requires field painting after installation, then repainting on a normal exterior maintenance cycle — often shorter here than inland, given the UV and moisture exposure. Every repaint is also a re-inspection point: cut edges, seams, and fastener heads all need to be checked and resealed, because the coating is what's standing between the weather and the wood fiber underneath.
What Ongoing Maintenance Actually Looks Like
- Fiber cement (ColorPlus): occasional wash-down, periodic caulk check at trim joints, no scheduled repainting under normal conditions
- Fiber cement (primed, field-painted): standard exterior repaint cycle, similar to painted wood trim
- Engineered wood: factory coating inspection, prompt caulk repair at any cut edge or penetration, repaint on a defined cycle, closer attention after any moss or algae buildup
Installation Sensitivity
Both products are manufactured goods that perform to spec only when installed to spec — that part is true across the board, and it's worth being honest about. Fiber cement has clear, published installation requirements: minimum clearances above rooflines and decks, specific fastener patterns, and factory-primed cut edges. Get those wrong and any siding product will underperform.
Where engineered wood raises the stakes further is that every cut edge, every field modification around a window or vent, has to be sealed correctly or it becomes a moisture entry point into the wood fiber itself — not just a cosmetic gap. Fiber cement cut edges should be treated too, but because the base material isn't organic, a missed edge is a durability risk in a different, generally slower-developing way than it is with an engineered wood substrate. That difference in consequence is a big part of why we don't install engineered wood: we'd rather not build a system where a single missed caulk line, years down the road after a crew has moved on, can become the difference between a cosmetic fix and a rot repair.
Warranty Comparison
| Factor | James Hardie Fiber Cement | Typical Engineered Wood |
|---|---|---|
| Substrate warranty | Non-prorated coverage on the siding substrate, transferable to a subsequent owner within program terms | Substrate coverage, often prorated after an initial full-coverage period |
| Finish warranty (ColorPlus vs. field paint) | Separate, extended finish warranty covering the factory finish | Field-applied paint typically falls under standard paint manufacturer warranty terms, not the siding maker's |
| Transferability | Transferable to new owners, which matters for resale | Varies by manufacturer and program |
Warranty terms change over time and vary by product line, so we always walk homeowners through the current written warranty rather than relying on a summary. But structurally, pairing a factory-cured finish with a mineral-based substrate gives Hardie's warranty less to hedge against — there's no field paint variable and no organic substrate variable both needing to hold up at once.
Cost Considerations Over Time
Engineered wood siding often carries a lower installed cost upfront than fiber cement, and we won't pretend otherwise — it's a real factor for a lot of homeowners, and it's a legitimate reason some contractors offer it. What we ask homeowners to weigh against that is the cost of ownership over the 20-plus years most people plan to keep a home: repaint cycles, caulk maintenance, and the risk profile if a sealed edge gets missed somewhere on a home that's going to sit in salt air and driving rain for decades. For some homeowners on a tighter renovation budget, engineered wood is a reasonable choice made with open eyes. We simply don't install it ourselves, because we'd rather stand fully behind one product system we trust in this climate than offer two and split our expertise and warranty relationships across both.
Why We Standardized on James Hardie
We made the call to install James Hardie fiber cement exclusively — not LP SmartSide, not vinyl, not Cemplank or Allura, not primed cedar or spruce — because it's the product system that best matches what this part of Skagit County actually does to a house year after year: salt air, sustained driving rain, and a moss season that doesn't really end. Hardie's HZ product lines are engineered specifically for climate zones like ours, the ColorPlus finish holds up to marine UV and humidity without a repaint cycle, and the substrate itself doesn't feed rot even when a maintenance item gets missed for a season. Installing one product system also means our crews are deeply practiced in its specific requirements — clearances, fastening, flashing details — rather than switching methods between product lines.
If you're weighing fiber cement against engineered wood for a home in Anacortes, we're glad to walk through your specific house, elevations, and exposure and give you a straight answer — including where the cost trade-offs really land for your project. Reach out for a free, no-pressure estimate and we'll take a look together.