Bellingham Exterior Two Products, One Question: What Survives a Bellingham Winter?
Homeowners doing their research on siding replacement in Whatcom County almost always come across the same two contenders: James Hardie fiber cement and LP SmartSide engineered wood. Both are marketed as upgrades over vinyl and both look good on a sample board in a showroom. But a sample board doesn't sit through thirty years of salt air off Bellingham Bay, driving rain off the Sound, and the long moss season that keeps north-facing walls damp from October through May. That's the environment we actually build in, and it's the reason our company installs only James Hardie fiber cement siding.
What LP SmartSide Gets Right
We'll say this plainly: LP SmartSide is a legitimate product, and it's a real step up from oriented strand board (OSB) siding of decades past. It's engineered wood strand, treated with zinc borate and resin-saturated, then coated for weather resistance. It's lighter than fiber cement, easier on installers' saw blades, and it holds paint reasonably well when the finish is maintained on schedule. For some climates and budgets, it's a defensible choice.
Why We Don't Install It Here
Our reservations aren't about workmanship on any single job — they're about the core material and how it behaves over the long run in this specific climate.
It's Still Wood at Its Core
Engineered wood is wood. The zinc borate treatment resists rot and the resin coating sheds water, but both are surface and matrix treatments on a substrate that will absorb moisture if that protective layer is ever compromised — a nail pop, a caulk joint that opens up, a cut edge that wasn't field-treated correctly during installation. In a dry climate that's a minor risk. In a county that sees over 35 inches of annual rainfall, plus wind-driven rain off the water and months of shaded, moss-friendly north walls that never fully dry out, it's a risk we're not willing to build a roof over someone's head with.
Installation Sensitivity
SmartSide performs the way it's supposed to only when every cut edge, joint, and fastener penetration is sealed exactly to spec, every time, on every job. That's a high bar to hold consistently across a crew and a career, and the margin for error is thinner than with a material that isn't moisture-reactive at its core. We'd rather standardize on a product where a missed touch-up doesn't turn into a callback five years later.
Combustibility
Engineered wood is a wood product — it burns. Fiber cement does not. That's not a dig at LP; it's just physics, and for us it's a meaningful difference when we're talking about the material that covers an entire home.
Warranty Structure
LP's warranties are solid on paper, but they're prorated over time and can carry maintenance-compliance requirements — meaning the homeowner has to prove they kept up with repainting and caulking on schedule to keep full coverage. That puts the burden of warranty protection on the homeowner's maintenance records years down the road, not just on the product.
Why We Standardized on James Hardie
Fiber cement is sand, cement, and cellulose fiber — there's no wood substrate to rot, swell, or feed moss growth the way exposed wood grain can. It's non-combustible, which matters both for the home and often for insurance considerations. James Hardie also engineers its HZ product lines for specific climate zones, and the HZ5 line specified for the Pacific Northwest is built around exactly the conditions we deal with here: sustained moisture exposure and temperature swings across the seasons.
The ColorPlus factory-finish option bakes the color onto the board under controlled conditions before it ever reaches the jobsite, which gives a more consistent, fade-resistant finish than field-applied paint and reduces how often a homeowner needs to think about repainting at all. Combined with Hardie's transferable limited warranty, it's a system we can stand behind for the long haul rather than one that depends on the homeowner keeping up a maintenance schedule to stay protected.
Making the Comparison Concrete
| Consideration | LP SmartSide | James Hardie Fiber Cement |
|---|---|---|
| Core material | Engineered wood strand | Cement, sand, cellulose fiber |
| Combustibility | Combustible | Non-combustible |
| Moisture behavior | Treated wood, moisture-reactive if breached | Not wood-based; does not rot or swell |
| Finish | Field or factory-primed, repaint on schedule | ColorPlus factory finish available, longer repaint cycle |
| Warranty | Prorated, maintenance-dependent | Transferable limited warranty |
Our Bottom Line
We're not going to tell you LP SmartSide is a bad product — it isn't, and plenty of contractors install it well. But when we weigh what actually holds up through a Bellingham winter, a Whatcom County moss season, and decades of salt-tinged rain off the water, fiber cement is the material we're willing to put our name behind. That's why it's the only siding system we install.
If you're weighing your own siding options, we're happy to walk through what we see on homes in this area and give you an honest read on what makes sense for yours. Reach out for a free, no-pressure estimate — no obligation, just a straight answer.