Bellingham Siding What LP SmartSide Actually Is
LP SmartSide is an engineered wood siding product — strand-based wood substrate treated with resin and zinc borate, then coated with a wax-based overlay to resist moisture, and finished with a primer. It's a legitimate step up from old-school OSB siding, and LP has put real engineering into making wood-based siding hold up better than the composite products that gave engineered wood a bad name in the 1990s. Homeowners like it for the wood-grain look, the lighter weight, and a lower upfront material cost than fiber cement. We don't dispute any of that. We just don't install it, and we think Bellingham homeowners deserve the honest reasons why.
The Core Issue: It's Still Wood
Strand and resin technology aside, LP SmartSide's substrate is wood fiber. Wood fiber swells when it takes on moisture and shrinks when it dries out. The zinc borate treatment resists rot and the overlay resists water intrusion, but the product still depends on an intact factory coating and correctly sealed cut edges, seams, and fastener penetrations to keep water out over the long run. Once that coating is compromised — a missed caulk joint, a cut edge left unsealed, a fastener that backs out — moisture has a path into a wood-based product, and wood-based products don't handle repeat wetting well.
That matters more here than it does in a dry climate. Whatcom County sits in a marine environment with salt air off Bellingham Bay, driving rain that comes in sideways off Puget Sound storms, and a long moss season that keeps north-facing walls damp for months at a stretch. Siding on a Bellingham home isn't dealing with the occasional summer thunderstorm — it's dealing with sustained, low-grade moisture exposure for a good chunk of the year. That's exactly the condition engineered wood siding is least suited to.
Installation Sensitivity
LP SmartSide's manufacturer warranty is genuinely strict about installation details — proper flashing, minimum clearances above grade and roof lines, sealed cut edges, correct fastener spacing and depth. When it's installed exactly to spec by a crew that treats every one of those details as non-negotiable, it performs reasonably well. The problem is that the margin for error is thin, and on a real job site with weather windows, subcontractor schedules, and dozens of cut edges and penetrations per house, thin margins get tested. We'd rather not put our name on a product where a single missed detail — one unsealed cut, one gap in caulking — can become a moisture problem that doesn't show up for a few years, by which point it's a homeowner's problem, not ours.
Maintenance Burden Over Time
LP SmartSide requires repainting on a maintenance cycle — the factory primer is not a finish coat, and the topcoat paint job needs upkeep like any painted wood surface. In a wet coastal climate, that maintenance interval tends to run shorter than it would in a dry inland region, because UV, moisture cycling, and moss growth all accelerate coating wear. Homeowners who choose engineered wood siding are signing up for a repainting schedule for the life of the product. That's a legitimate choice for some budgets and some homeowners — we just want it understood upfront rather than discovered five years in.
Where LP SmartSide Genuinely Makes Sense
- Drier climates where sustained moisture exposure isn't a year-round factor
- Budgets where the lower material cost matters more than a longer maintenance-free window
- Homeowners who accept and plan for a repainting cycle as part of ownership
- Projects with a contractor who will guarantee strict adherence to every flashing and sealing detail in the manufacturer spec
None of that makes it a bad product. It makes it a product with a narrower margin for error in a climate we don't think rewards narrow margins.
Why We Install James Hardie Instead
We install James Hardie fiber cement exclusively, and the reasoning comes down to the same climate factors above, applied in the other direction. Fiber cement is cement, sand, and cellulose fiber — it doesn't swell, rot, or feed moss the way a wood-based substrate can, and it's non-combustible. Hardie's ColorPlus factory finish is baked on and warrantied separately from the substrate, which means no repainting cycle to plan around for years. Hardie's HZ5 product line is engineered specifically for climates with the kind of moisture cycling, freeze-thaw swing, and sustained damp exposure that Whatcom County sees. It's also a widely used, well-understood product regionally, with a strong transferable warranty that holds up whether the home changes hands or not.
| Factor | LP SmartSide | James Hardie Fiber Cement |
|---|---|---|
| Substrate | Engineered wood strand | Fiber cement (non-combustible) |
| Moisture behavior | Resistant if coating stays intact | Does not swell or rot |
| Finish maintenance | Repainting cycle required | Factory ColorPlus finish, no repaint cycle |
| Installation margin for error | Thin — sealing details are critical | More forgiving, still requires correct install |
Our Standard, Not a Verdict on the Product
We're not telling Bellingham homeowners that LP SmartSide is a bad choice everywhere — we're telling you why it's not the product we choose to put our name behind, on our home turf, in our climate. Fiber cement has simply held up better against salt air, driving rain, and moss season in the projects we've seen and the installations we stand behind. If you're weighing siding options for a home in Whatcom County, we're happy to walk through the trade-offs in person and give you a straight answer about what will actually hold up on your specific house.
If you'd like a second opinion on your siding plans, we offer free, no-pressure estimates — reach out and we'll take a look at your home and talk through what makes sense for your budget and your walls.