Chuckanut Exterior Two Products Homeowners Cross-Shop
If you're replacing siding in Chuckanut, there's a good chance two products have come up in your research: James Hardie fiber cement and LP SmartSide engineered wood. Both are marketed as upgrades over old cedar or vinyl. Both come in lap, panel, and trim configurations. Both look good on a spec sheet. But they are fundamentally different materials, and in a place like Whatcom County — where homes deal with salt air off Bellingham Bay, driving winter rain, and a moss season that can stretch from October into May — that difference matters more than it does in drier climates.
We install only James Hardie fiber cement siding. We don't install LP SmartSide. This page explains what each product actually is, where LP SmartSide performs reasonably well, and why we've drawn the line where we have. Our goal isn't to talk you out of doing your own research — it's to give you the same information we used when we made this call for our own business.
What LP SmartSide Actually Is
An Engineered Wood Product
LP SmartSide is a wood-strand product. Wood strands are bonded with resin under heat and pressure into panels and lap boards, then treated with a zinc borate preservative that resists fungal decay and insects, and coated with a primer at the factory. It's a legitimate step up from raw dimensional lumber siding — the engineering makes it more dimensionally stable than solid wood, and the borate treatment addresses the rot vulnerability that plagued older wood sidings.
Still a Wood Product at Its Core
The important word is still "wood." Wood strands, even engineered and treated ones, are organic material that swells, shrinks, and can absorb moisture at cut edges, fastener penetrations, and any spot where the factory coating is breached. LP has improved the product significantly over the versions that had documented issues in the 1990s and early 2000s, and the zinc borate treatment is a real improvement. But the underlying physics of a wood-based product exposed to a wet marine climate haven't changed.
What James Hardie Fiber Cement Actually Is
A Cement-Based Composite
James Hardie siding is made from a mix of Portland cement, sand, and cellulose fiber, cured into a rigid board. There's no wood strand structure to swell or delaminate, and no organic material for fungus to feed on. It's inherently non-combustible — a distinction that matters more every wildfire season in the Pacific Northwest, even in a coastal county like Whatcom that isn't a classic fire-risk zone.
Climate-Engineered Product Lines
Hardie makes region-specific formulations under its HZ5 and HZ10 designations, engineered for different moisture and freeze-thaw exposures across the country. For a marine climate like ours, the HZ5 line is the standard specification, built to hold up to sustained damp conditions rather than the drier climates some fiber cement lines were originally engineered for.
ColorPlus Factory Finish
Rather than a job-site primer coat, Hardie's ColorPlus finish is baked on in a controlled factory environment in multiple coats, then backed by a separate finish warranty against fading and peeling. That's a different proposition than a primed board that still needs field-applied topcoat and ongoing repainting.
How Each Handles Whatcom County's Moisture
This is where the two products diverge most in a place like Chuckanut. Three regional conditions stack up against each other here:
- Salt air: Proximity to Bellingham Bay means airborne salt settles on exterior surfaces year-round, accelerating coating breakdown and metal fastener corrosion.
- Driving rain: Wind-driven rain off the Sound doesn't just wet a wall surface — it pushes moisture into seams, laps, and any compromised caulk joint.
- Long moss season: Shaded north and west elevations under our tree cover stay damp for months at a time, and moss holds moisture directly against the siding surface.
Fiber cement doesn't rot, and it doesn't provide organic material for moss and mildew to feed into. It will still get wet and it still needs to be able to dry, which is why proper flashing and drainage gaps matter regardless of material — but the material itself isn't degrading from that moisture exposure. Engineered wood, even with borate treatment, is more sensitive to sustained damp conditions, particularly at cut ends, seams, and fastener points where the factory coating can be compromised during installation or over time.
Fire Resistance
James Hardie fiber cement is non-combustible. LP SmartSide, as an engineered wood product, is combustible, though the panel construction performs differently than raw lumber in fire testing. For homeowners weighing insurance considerations or simply wanting one less combustible material on their exterior, this is a straightforward point in fiber cement's favor. It's not the only factor in a siding decision, but it's one that doesn't require interpretation.
Long-Term Maintenance and Finish Life
| Factor | James Hardie (ColorPlus) | LP SmartSide |
|---|---|---|
| Factory finish | Baked-on multi-coat ColorPlus | Factory primer; finish paint typically field-applied |
| Repainting cycle | Often 15+ years before repaint needed | Typically 5-10 years depending on exposure |
| Moisture sensitivity at edges/seams | Low — non-organic material | Moderate — requires sealed cut edges and maintained caulk joints |
| Susceptible to insect damage | No | Reduced by borate treatment, not eliminated |
| Susceptible to rot if coating fails | No | Yes, at compromised areas |
The practical difference shows up years down the road, not on install day. A homeowner who chooses engineered wood siding is signing up for a maintenance schedule — periodic inspection of caulked joints and cut ends, more frequent repainting, and prompt attention to any coating damage. In a wet climate, deferred maintenance on a wood-based product has real consequences. Fiber cement is far more forgiving of the maintenance gaps that happen in real life.
Warranty Comparison
| James Hardie | LP SmartSide | |
|---|---|---|
| Substrate warranty | Typically 30 years, non-prorated | Typically 5-year labor plus longer prorated material coverage; terms vary by product line |
| Finish warranty | Separate ColorPlus finish warranty, typically 15 years | Coverage depends on paint system applied, often by others |
| Transferability | Transferable to subsequent owners under stated terms | Varies by product line and dealer |
Warranty terms change over time and always deserve a careful read of the current documentation rather than a summary like this one. The broader point stands: Hardie's non-prorated substrate warranty paired with a separate factory finish warranty is a more complete package than a primed wood product where the finish coat, and its warranty, often depends on what's applied after installation.
What Correct Installation Requires
Neither product performs to its potential if installed poorly. Whatcom County's rain load means installation details aren't optional extras — they're the difference between a siding job that lasts decades and one that fails early.
- Correct fastener type, spacing, and penetration depth for the specific product and substrate
- Proper flashing at every window, door, and roof-to-wall transition
- A drainage gap or rainscreen behind the siding so incidental moisture can escape rather than sit against the wall
- Sealed and primed cut ends on every field cut, especially at butt joints and corners
- Manufacturer-specified clearance from grade, decks, and roof lines
- Caulk joints installed with the right product and inspected periodically, not just at installation
Fiber cement is somewhat more tolerant of small installation lapses because the material itself doesn't rot. Engineered wood is less forgiving — a missed cut-end seal or a caulk joint that fails in year six can allow moisture into the wood strand core in a way that's not always visible from the outside until the damage is advanced.
Cost Considerations Over the Life of the Siding
LP SmartSide typically carries a lower material and installation cost upfront than James Hardie fiber cement. That's a real and fair advantage for a homeowner working within a tight budget, and we won't pretend otherwise. Where the comparison shifts is over a 20- to 30-year ownership window: fewer repaint cycles, lower risk of moisture-related repair costs, and a longer substrate warranty tend to close, and often reverse, the gap in total cost of ownership. Whether that trade-off makes sense depends on how long you plan to own the home, your budget today, and how much ongoing maintenance you want to take on.
Why We Standardized on Hardie
We made a business decision to install only James Hardie fiber cement, not because LP SmartSide is a bad product, but because we didn't want to split our crews' expertise and warranty accountability across materials with very different moisture tolerances in a climate that doesn't give much room for error. Fiber cement's non-combustible, non-organic composition, the HZ5 climate-specific formulation, the ColorPlus factory finish, and the strength of the substrate warranty added up to the standard we wanted to put our name behind on every home we side in Chuckanut and the surrounding county.
If you're weighing siding options for your home, we're happy to walk through what we see on Whatcom County houses and give you a straight answer about what we'd recommend for your specific situation. Reach out for a free, no-pressure estimate using the form below.