Fairhaven Siding Two Different Materials, Two Different Bets
Homeowners in Fairhaven and the surrounding Bellingham area usually narrow a siding decision down to two finalists: engineered wood siding, most commonly sold as LP SmartSide, and fiber cement siding, the category James Hardie built its name on. Both are real upgrades over vinyl. Both hold paint well and come pre-primed or factory-finished. But they are built from fundamentally different materials, and that difference matters more here than it does in a dry inland climate. Wood, even engineered wood, is an organic material that reacts to moisture. Fiber cement is a mineral-based product that doesn't. In a marine climate with salt air off Bellingham Bay, driving rain off the Sound, and a moss season that can stretch from October into May, that single distinction ends up driving most of the long-term outcome.
We're not going to pretend one of these products is junk. LP SmartSide has a legitimate engineering story behind it. But after years of installing and repairing siding in Whatcom County, we made a deliberate call to install only James Hardie fiber cement. This page explains both products honestly, then explains why we drew that line.
What LP SmartSide Actually Gets Right
LP SmartSide is strand-based engineered wood — wood fibers bonded with resin under heat and pressure, then coated with a resin-saturated overlay and treated with a zinc borate preservative to resist fungal decay and insects. It's a genuine improvement over old-school untreated wood or plain OSB siding. It's lighter than fiber cement, easier on saw blades and installer lungs (no silica dust), and it holds a paint finish reasonably well when it's kept sealed and painted on schedule.
It's also less brittle than fiber cement in cold-weather installation, and some builders like that it's a single, lighter-weight product to handle on a ladder. For a builder working in a dry, moderate climate with a maintenance-attentive owner, it can be a reasonable product. That's a fair statement, and we're not going to walk it back just because we don't install it.
The Manufacturer's Own Caveats
Even LP's own installation and warranty documentation is specific about what has to happen to keep the product performing: cut edges must be sealed with the specified sealant before installation, joints and penetrations need continuous caulking, minimum ground clearance and flashing details have to be followed precisely, and the finish has to be maintained — meaning repainted — on a defined cycle. None of that is unusual for a wood-based product. But it does mean the product's long-term success depends heavily on maintenance discipline and installer precision, year after year, in a climate that doesn't give you many dry weeks to do that maintenance in.
Where Engineered Wood Runs Into Trouble Here
Edge Swelling and Cut-Edge Exposure
The most common engineered-wood siding failure we see on service calls isn't a mystery — it's edge swelling at butt joints, corners, and cut-outs where a factory edge was cut on site and the exposed strand board wasn't sealed correctly, or where the sealant has worn thin over time. Once moisture gets into that cut edge, the strands swell, the paint film cracks along the swelling, and moisture intake accelerates from there. It's a slow failure, which is part of the problem — it's easy to miss until the trim boards start telegraphing the damage.
Moisture and a Long Wet Season
Whatcom County doesn't get occasional rain — it gets a long, low-intensity wet season with driving rain off the Strait and Bellingham Bay pushed sideways by wind. That's a different exposure than a short, hard summer thunderstorm climate. Engineered wood siding needs time to dry out between wetting events to stay ahead of moisture uptake at vulnerable points. In a climate where six or eight months of the year offer few consecutive dry days, that drying window shrinks, and any gap in caulking, flashing, or paint film has more opportunity to do damage before anyone notices.
Moss and Organic Growth
The same shade, humidity, and tree cover that make Fairhaven's older neighborhoods attractive also produce a long moss and algae season on north-facing and shaded walls. Moss holds moisture against the surface it grows on. On a wood-based product, sustained moss contact at a compromised joint or edge is exactly the kind of slow, damp exposure that accelerates decay. It's manageable with regular cleaning, but it's one more maintenance item added to a product that already asks for a repaint cycle and periodic caulk inspection.
What Fiber Cement Is Made Of — and Why It Behaves Differently
James Hardie fiber cement siding is made from Portland cement, sand, and cellulose fiber, cured under pressure and heat. There's no wood strand structure to swell, no resin bond to break down under sustained moisture, and nothing for insects to feed on. It's non-combustible, which matters increasingly for insurance underwriting even in a rain-heavy climate where wildfire risk feels distant. Cut edges still need to be primed before installation — that part isn't optional on either product — but a cut edge on fiber cement that gets missed doesn't swell the way an unsealed engineered-wood edge does. The material itself simply isn't reactive to water in the same way.
That's the core of why we standardized on it. It's not that fiber cement is maintenance-free — no exterior cladding is — it's that the failure modes are gentler and slower, and the product's performance depends less on a homeowner catching every maintenance item on schedule for thirty years straight.
Side-by-Side: The Factors That Actually Matter in This Climate
| Factor | LP SmartSide (Engineered Wood) | James Hardie (Fiber Cement) |
|---|---|---|
| Core material reaction to sustained moisture | Wood strand can swell if edges/joints fail | Cement-based, does not swell or rot |
| Cut-edge treatment | Required sealant, ongoing vigilance | Required primer, less consequence if missed later |
| Fire classification | Combustible | Non-combustible |
| Insect/rot vulnerability | Borate-treated but organic core | None — mineral-based |
| Factory finish option | Primed; field-painted typical | ColorPlus factory-baked finish available |
| Typical repaint cycle | Field paint on a maintenance schedule | ColorPlus finish extends years before repaint |
| Weight / installer handling | Lighter | Heavier, requires fiber-cement blades and dust control |
| Manufacturer warranty structure | Product-specific limited warranty | Long-term limited warranty, transferable |
The James Hardie Product Lines We Actually Install
HZ5 Climate Engineering
James Hardie engineers its HZ product lines by climate zone, and the HZ5 formulation is the one specified for regions with sustained moisture exposure and freeze-thaw cycling — which describes Whatcom County's exposure profile reasonably well. It's not a marketing distinction; the formulation is adjusted for how the product needs to perform in a wetter, cooler climate compared to a dry-zone HZ10 product used in the Southwest.
ColorPlus Technology
Rather than field-painting siding after installation, ColorPlus finishes are baked on at the factory in multiple coats under controlled conditions, which produces a more consistent, more UV- and moisture-resistant finish than a field-applied paint job — and comes with touch-up and repair kits matched to the exact finish batch. For a homeowner in a low-sun, high-moisture climate, that factory cure matters: less time exposed to wet weather during the finish-curing window than a site-painted product would need.
Lap, Panel, and Trim Systems
We install Hardie's full system — lap siding in multiple exposure widths, vertical panel siding for accent applications, and matched trim boards — so the whole envelope is a single compatible system rather than a patchwork of materials with different expansion rates and moisture behaviors at the joints.
The Warranty Difference, in Plain Terms
James Hardie backs its fiber cement products with a long-term limited warranty that is transferable to a subsequent homeowner, which matters in a market where houses change hands and buyers ask pointed questions about siding age and condition during inspection. Engineered wood warranties tend to be more tightly conditioned on documented maintenance — proof of repainting on schedule, proof of caulk maintenance — which is reasonable from the manufacturer's standpoint but puts the burden of warranty-keeping on the homeowner in a way that's easy to lose track of over a decade or two.
Installation Is Where Either Product Succeeds or Fails
We want to be fair here: a poorly installed fiber cement job will fail too. Material choice doesn't override installation quality — it changes how forgiving the material is of small installation errors over time. Whether you go with us or another contractor, here's what correct installation has to include on a coastal Whatcom County home regardless of siding material:
- Proper weather-resistive barrier and rainscreen gap behind the cladding, not just house wrap direct to sheathing
- Correct flashing at every window, door, and penetration, integrated with the barrier — not just caulked over the top
- Manufacturer-specified fastener type, spacing, and penetration depth
- Minimum clearance from grade, decks, and roof lines to keep splashback and standing water off the cladding
- All cut edges primed or sealed per manufacturer spec before the piece goes on the wall
- Butt joints and seams treated exactly per manufacturer detail, not field-improvised
Why We Standardized on Fiber Cement Only
We install one product family, James Hardie fiber cement, on every job. That's a deliberate business decision, not a default. Running one system means our crews install it correctly every time instead of switching techniques between materials, our warranty conversations with homeowners are consistent, and we're not asking a Fairhaven homeowner to bet thirty years of exterior performance on a maintenance schedule staying perfect through every wet Whatcom County winter in between. Engineered wood can be a defensible choice for the right owner in the right climate. We just decided we'd rather build our reputation on a material that gives homeowners more room for error over the decades their siding is actually up there.
If you're weighing a siding replacement in Fairhaven or anywhere in Whatcom County, we're glad to walk your specific house — sun exposure, tree cover, wall orientation to the weather — and give you a straight answer, not a sales pitch. Reach out for a free, no-pressure estimate using the form below.