Bellingham Homeowners in Bellingham and across Whatcom County ask us fairly often why we don't offer LP SmartSide. It's a legitimate question — SmartSide is a well-known product, widely available, and plenty of contractors in this region install it. Our answer isn't that it's a bad product. It's that after years of doing siding work in a marine climate with driving rain, salt air off Bellingham Bay, and long stretches of shaded, moss-friendly moisture, we made a professional decision to standardize on one material — James Hardie fiber cement — and stop installing anything else. This page explains the trade-offs that led to that decision.
What LP SmartSide Actually Is
LP SmartSide is an engineered wood siding product. It's made from wood strands and fibers bonded with resins, then treated with a zinc borate-based process (LP calls it SmartGuard) intended to resist moisture absorption, fungal decay, and termites. It comes in lap siding, panel siding, and trim profiles, usually factory-primed and sometimes available pre-finished through LP's ExpertFinish program.
It has real advantages. It's lighter than fiber cement, which can make it faster and less physically demanding to install. It holds a screw and nail well, cuts easily without the silica dust fiber cement produces, and costs less per square foot in most markets. For a lot of homes, in drier climates, it's a reasonable, budget-conscious choice.
Why We Don't Install It Anyway
Our concern isn't the engineering — LP has put real research into stabilizing wood strand siding against moisture. Our concern is what happens over 15-30 years on a home exposed to Pacific Northwest weather, and what that means for maintenance obligations, warranty coverage, and the long-term condition of the wall behind the siding. Wood-based products, no matter how well engineered, share one property that fiber cement does not: the base material is still organic. Given enough sustained moisture exposure — which is exactly what Whatcom County delivers most of the year — an organic substrate is working against you instead of with you.
We used to install a range of products. Over time, the callbacks, warranty disputes, and repaint jobs we saw were disproportionately tied to engineered wood and other wood-based sidings, not fiber cement. That pattern is what pushed us to simplify to one product line we can install and stand behind with confidence.
Engineered Wood vs. Fiber Cement: The Core Difference
| Factor | LP SmartSide (engineered wood) | James Hardie (fiber cement) |
|---|---|---|
| Base material | Wood strand/fiber with resin binder | Cement, sand, and cellulose fiber |
| Combustibility | Combustible (wood-based) | Non-combustible |
| Moisture response | Resists absorption when finish is intact; vulnerable at cut edges, joints, fastener holes | Dimensionally stable; does not swell, rot, or delaminate from moisture |
| Finish requirement | Field paint/caulk required and must be maintained on a schedule | Factory-baked ColorPlus finish; no field painting required for most homeowners |
| Insect/pest exposure | Treated against pests, but still an organic substrate | Not a food source for insects; nothing for pests to exploit |
| Warranty structure | Prorated; can be conditioned on documented maintenance | Non-prorated, transferable limited warranty on the substrate; ColorPlus finish warranty covers coating separately |
What Bellingham's Climate Does to Wood-Based Siding
Salt Air Off the Bay
Bellingham sits directly on Bellingham Bay, and salt-laden marine air reaches homes well inland into Whatcom County. Salt air accelerates the breakdown of paint films and finishes, which matters enormously for a product whose entire moisture defense depends on an intact factory or field finish. Once that finish starts to chalk, crack, or thin — which happens faster near the water — the wood substrate underneath is exposed to exactly the kind of moisture it's least equipped to handle long-term.
Driving Rain
This isn't a light-drizzle climate. Storms off the Strait of Georgia and Puget Sound routinely bring wind-driven rain that hits siding at an angle, forcing water into laps, seams, and butt joints rather than just running down the face of the wall. Any siding product depends on caulking and flashing details at those joints to stay watertight. With an organic substrate, a failed joint doesn't just mean a cosmetic issue — it means active moisture contact with wood fiber, which is where swelling, soft spots, and eventual rot begin.
Moss Season
Whatcom County's long, wet, shaded winters are ideal moss-growing conditions, and moss doesn't just grow on roofs — it colonizes siding, especially on north-facing walls and anywhere tree cover blocks sun and airflow. Moss holds moisture directly against the siding surface for extended periods. On a mineral-based product like fiber cement, that's a cleaning and appearance issue. On an engineered wood product, sustained surface moisture from moss is one more input working against the finish and the substrate underneath it.
The Maintenance Schedule That Comes With the Territory
Manufacturers of engineered wood siding are upfront that the product requires ongoing maintenance to perform as designed — this isn't a hidden flaw, it's stated in their own installation and warranty documentation. In a climate like ours, that maintenance schedule tends to compress rather than stretch out. A realistic maintenance checklist for engineered wood siding in Whatcom County looks like this:
- Inspect all caulked joints, corners, and trim seams annually for cracking or separation
- Recaulk failed joints promptly, before the next wet season
- Repaint on the manufacturer's recommended cycle, often faster near salt air exposure
- Keep siding at least 6 inches above grade and clear of soil, mulch, or plantings
- Remove moss and organic debris from siding surfaces, not just the roof
- Watch cut ends, fastener heads, and any field-cut edges for exposed, unsealed material
- Document maintenance if you want warranty claims to hold up later
None of this is unreasonable to ask of a homeowner. But it's a real, recurring cost and time obligation — one that a lot of buyers don't fully register until a few years in, when the first recaulk-and-repaint cycle comes due.
Warranty Structure: What the Fine Print Actually Says
Engineered wood warranties are typically prorated, meaning the coverage value declines over the life of the product, and they often include maintenance obligations as a condition of coverage. If a claim is filed and the manufacturer determines the finish wasn't maintained on schedule, or that field cuts weren't sealed per instructions, that can affect what's covered. We're not saying that's deceptive — it's disclosed in the warranty documents — but it does shift real responsibility onto the homeowner over the life of the siding, and installation quality has to be exact for the warranty to mean what it appears to mean at the point of sale.
James Hardie's fiber cement warranty structure is simpler for the reason that the product doesn't carry the same maintenance dependency. There's no field-applied finish to keep up on, no organic substrate reacting to moisture cycles, and the transferable, non-prorated limited warranty holds up without a homeowner needing to log a repaint schedule.
Installation Sensitivity: Where Problems Actually Start
Most of the engineered wood siding failures we've seen over the years didn't trace back to a defective product. They traced back to installation and detailing: unsealed cut ends, joints caulked with the wrong product or none at all, siding installed too close to grade, or trim details that let water sit instead of shed. Engineered wood siding is less forgiving of these mistakes than fiber cement, because every one of those errors gives moisture direct access to an organic material.
That sensitivity is exactly why we stopped installing multiple products years ago. It's hard to guarantee flawless execution of every joint, every cut end, every flashing detail across a crew and across every job, on every product line, in every configuration. Standardizing on one system lets our crews build deep, repeated expertise in the flashing details, fastening patterns, and joint treatment that one product demands — instead of spreading that expertise thin across several.
Why We Standardized on James Hardie
James Hardie fiber cement siding is cement, sand, and cellulose fiber — non-combustible, dimensionally stable, and not a food source for the kind of biological activity (rot, insects, mold) that organic sidings have to be engineered to resist. The ColorPlus factory finish is baked on under controlled conditions and backed by its own finish warranty, so homeowners aren't relying on a field-applied paint job holding up against salt air and driving rain for the life of the siding. Hardie's HZ5 product line is engineered specifically for climates like ours — freeze-thaw cycling, sustained moisture, and coastal exposure — rather than a general-purpose specification.
We also like that it gives us one system to install extremely well rather than several to install adequately. Our crews know Hardie's fastening schedules, joint treatments, and flashing requirements cold, which is where most long-term siding failures — on any product — actually originate.
Is LP SmartSide Ever the Right Call?
For a homeowner further from marine exposure, with good roof overhangs, full sun exposure on most elevations, and a willingness to stay on top of a repaint and recaulk schedule, engineered wood siding can perform reasonably well. That's just not the profile of most homes we work on in Bellingham and the surrounding Whatcom County towns, where salt air, driving rain, and shaded, moss-prone walls are closer to the rule than the exception. Given that reality, we'd rather tell you honestly why we don't install it than sell you a product we're not confident will hold up here without a maintenance commitment most homeowners underestimate.
If you're weighing siding options for a home in Bellingham or anywhere in Whatcom County, we're happy to walk your specific house — sun exposure, roof overhangs, moss history, salt air exposure — and give you a straight, no-pressure estimate for what we'd actually recommend and why.