Bellingham Siding What LP SmartSide Actually Is
LP SmartSide is an engineered wood siding made from strand-based wood substrate (similar in concept to OSB) that's treated with a zinc-borate and resin process LP calls SmartGuard, then pressed and primed at the factory. It's a legitimate, code-compliant siding product with a real manufacturer warranty behind it, and plenty of homes around Whatcom County wear it without obvious problems. We're not here to tell you it's junk. We're here to explain why, as a company that installs siding for a living in a marine climate, we chose not to put it on your house.
Where SmartSide Earns Its Reputation
- Workability: Being wood-based, it cuts, nails, and handles more like traditional lap siding than fiber cement does, which some crews prefer.
- Impact resistance: It holds up well to hail and incidental impact — better than vinyl in most comparisons.
- Cost: It typically installs for less than premium fiber cement, which matters on a tight remodel budget.
- Warranty terms: LP backs SmartSide with a lengthy limited warranty, similar in structure to what other manufacturers offer.
Those are real advantages, and for some climates and budgets, SmartSide is a defensible choice. Bellingham just isn't that climate.
The Core Issue: It's Still a Wood Product
SmartGuard treatment is a genuine improvement over the OSB siding of decades past, and it does resist moisture and fungal decay far better than untreated engineered wood. But the underlying material is still a wood-strand substrate, and wood-based siding behaves fundamentally differently than fiber cement once it's exposed to years of wet weather:
- Cut edges and field joints are the weak point. Every field cut exposes raw substrate that has to be primed and sealed correctly, every time, or it becomes a place where moisture can start working its way in. On a real job site, in real weather, that level of consistency is hard to guarantee over hundreds of linear feet of siding.
- It needs ongoing paint film maintenance. The factory primer isn't a finish coat — it's a substrate for site-applied paint. That paint film is what's actually keeping water out, and paint films degrade with UV exposure and repeated wet-dry cycling. Miss a maintenance repaint cycle and you're relying on a compromised barrier.
- Installation tolerances are unforgiving. LP's warranty is explicit about clearances from grade, decks, and roof lines, fastener placement, and caulking at every penetration and joint. Installed exactly to spec, it performs. Installed even slightly off-spec — which is common in the trade — the margin for moisture intrusion narrows fast.
Why That Matters More Here Than Elsewhere
Whatcom County doesn't give a wood-based product much room for error. Homes near Bellingham Bay and along the Sound deal with salt-laden air that accelerates the breakdown of paint films and fasteners. The Pacific Northwest's driving, wind-blown rain doesn't just fall straight down — it drives sideways into laps, corners, and trim joints, which are exactly the spots where a wood-substrate product depends on caulking and paint holding the line. And our long moss season, especially on north-facing and shaded walls under tree cover, keeps siding damp for extended stretches even between storms. That combination — salt air, sideways rain, and months of shaded moisture — is a tough environment to ask any wood-based product to shrug off for 20-plus years with only routine maintenance.
None of that means SmartSide will fail on every house. It means the product's real-world performance here depends heavily on maintenance discipline and installation precision that we can control on day one, but that a homeowner has to keep up with for decades — repainting on schedule, re-caulking joints as they age, watching for the warning signs of a compromised seal before they become a wall problem.
Why We Standardized on James Hardie Instead
James Hardie fiber cement is made from cement, sand, and cellulose fiber — there's no wood substrate to protect from moisture in the first place. It's non-combustible, which matters for wildfire-adjacent insurance considerations even here on the wet side of the state, and it holds its shape and finish without depending on an unbroken paint film to keep water out of the material itself. Hardie's ColorPlus factory finish is baked on and warrantied separately from the substrate, which means the finish is engineered for UV and weather from the start rather than added on-site. And Hardie's HZ5 product line is specifically engineered for climates like ours — freeze-thaw cycling, sustained moisture, and coastal exposure.
We install one product because we'd rather be excellent at installing it correctly, every time, than stretch our crews across five products and get mediocre at all of them. Hardie, installed to spec, is what we're willing to put our name and warranty behind on a Bellingham home.
Talk to Us Before You Decide
If you're comparing siding options for a home in Bellingham or anywhere in Whatcom County, we're happy to walk your specific house — sun exposure, tree cover, proximity to the water — and give you a straight answer about what will actually hold up. Request a free, no-pressure estimate below and we'll tell you what we'd really do if it were our own house.