Whatcom County An Honest Look at LP SmartSide in a Wet Climate
Homeowners in Bellingham, Ferndale, and across Whatcom County ask us fairly often why we don't offer LP SmartSide. It's a legitimate product with real advantages, and plenty of contractors install it well. We're not here to tell you it's junk. We're here to explain why, after weighing how it performs against what our local climate demands, we chose not to put our name behind it — and why we install James Hardie fiber cement instead.
What LP SmartSide Actually Is
LP SmartSide is an engineered wood product. Strands of wood are bonded with resins under heat and pressure, then treated with a zinc borate process (LP calls it SmartGuard) to resist fungal decay and insects, and finished with a primer or factory coating. It's lighter than fiber cement, easier on saw blades, and generally less expensive to install. For a lot of markets, that combination makes sense.
Where it holds up well: impact resistance is genuinely good, it takes screws and nails without pre-drilling the way fiber cement sometimes benefits from, and LP backs it with a warranty that many homeowners find reassuring on paper.
Where the Trade-Offs Show Up
The catch is that it's still a wood-based product at its core. Wood, even engineered and treated wood, swells when it takes on sustained moisture — and Whatcom County doesn't give siding many dry breaks. Between the marine air off Bellingham Bay and the Strait of Georgia, driving rain off the Sound, and a moss and algae season that can run most of the year on shaded north and west elevations, the product is under near-constant moisture pressure.
LP SmartSide's long-term performance depends heavily on details that are easy to get right on installation day and easy to neglect five or ten years later:
- Cut edges and fastener penetrations have to be field-sealed with primer or caulk at the time of installation, and every one has to be caught — a missed edge is where moisture gets in first.
- Caulking joints around trim, windows, and panel seams need to stay intact. Caulk fails before siding does, and in our rain totals, a cracked joint doesn't take long to become a problem.
- Repainting on a schedule is part of the deal. Factory-primed and factory-finished versions still rely on the homeowner keeping the topcoat maintained, not just for looks but to keep water out of the substrate.
- Moss and algae growth on a wood-based surface in our climate can trap moisture against the panel longer than it would on an inorganic surface, especially on shaded elevations that don't get afternoon sun to dry out.
None of this means LP SmartSide is destined to fail. Installed carefully and maintained on schedule, it can perform for years. But "installed carefully and maintained on schedule" is doing a lot of work in that sentence, and we've found that gap between best-case installation and what actually happens over a decade of Pacific Northwest weather is where problems creep in — usually well after the installing contractor is out of the picture.
Why We Standardized on James Hardie Instead
We made a decision a while back to install one siding system, do it well, and stand behind it. James Hardie fiber cement is that system, for reasons that line up directly with the concerns above:
| Concern in Whatcom County's climate | How Hardie fiber cement addresses it |
|---|---|
| Moisture absorption at edges and cuts | Cement-based composition doesn't swell or rot the way wood-based substrates can |
| Coating maintenance burden | ColorPlus factory finish is baked on, backed by its own finish warranty, and cuts down on the repainting cycle |
| Wildfire and combustibility concerns | Non-combustible material — a consideration more homeowners are weighing regardless of region |
| Long-term climate exposure | HZ5 product line is engineered specifically for cold, wet Pacific Northwest conditions |
| Accountability over time | Strong transferable warranty that follows the home, not just the original owner |
Fiber cement isn't magic — it still needs correct installation, proper clearances, and caulking at the joints that call for it. No siding product installs itself or maintains itself. But the margin for error is wider, and the failure mode we see most with wood-based siding in this climate — slow moisture intrusion at edges and seams that isn't obvious until the damage is done — is much less of a risk with a cement-based panel.
Our Bottom Line
We're not going to tell a Whatcom County homeowner that LP SmartSide will definitely fail on their house. What we will say is that after years of watching how different siding products actually hold up against salt air, driving rain, and a long moss season here, we decided we'd rather install one product exceptionally well than offer several and hope the maintenance gets done. That's why every job we take on uses James Hardie.
If you're weighing siding options for a home in Whatcom County and want a straight answer about what will actually hold up on your specific house, we're happy to take a look and walk you through it. Reach out for a free, no-pressure estimate — no obligation, just an honest assessment.