Blaine Exterior LP SmartSide comes up a lot in siding conversations around Blaine, and for good reason — it's a legitimate product with real advantages. It's lighter than fiber cement, easier and faster to cut on site, and generally costs less installed. If you've priced out a full re-side, that price gap gets noticed. But after years of installing and repairing siding along the Whatcom County coastline, we made a deliberate decision to stop offering it. Here's the honest reasoning, not a sales pitch against a competitor's product.
What LP SmartSide Does Well
LP SmartSide is an engineered wood product — strand board coated with resin and treated with a zinc-borate process (LP calls it SmartGuard) to resist fungal decay and termites. It holds paint reasonably well, comes in lap and panel styles, and its lighter weight makes it easier to handle on tall gable walls or tricky elevations. For a lot of climates, installed correctly and maintained on schedule, it performs fine for years. We're not disputing any of that.
Where It Runs Into Trouble Here
The issue isn't the factory product — it's what happens to engineered wood siding once it's on a house in a place like Blaine. This stretch of Whatcom County sits right on the Strait of Georgia, which means salt-laden air, driving wind-driven rain off the water, and a moss and algae season that can run eight or nine months out of the year on shaded, north-facing walls. Engineered wood, no matter how it's treated, is still fundamentally a wood product with a wood core. That core is more vulnerable to moisture intrusion than a fiber cement panel once the surface protection is compromised.
Every cut end, every seam, every fastener penetration on an engineered wood panel is a place where the manufacturer's warranty requires field sealing — usually with a specific caulk or primer, on a maintenance schedule the homeowner has to keep up with indefinitely. Miss a recaulk cycle, let a gutter overflow onto a wall for one wet winter, or let moss build up against a butt joint, and moisture can work into the substrate before anyone notices. Once that happens with an engineered wood product, you're often looking at swelling, edge delamination, or soft spots rather than a simple spot repair.
Installation Sensitivity
Fiber cement forgives a lot of small installation variances. Engineered wood siding is less forgiving — clearances above rooflines and decks, gaps at trim, and butt joint treatment all matter more, because the manufacturer's warranty coverage is directly tied to whether those details were done to spec. We install a lot of siding, and we'd rather stand behind a product where correct installation and long-term durability aren't riding on a homeowner's caulk-gun maintenance schedule five years down the road.
Fire Exposure
LP SmartSide is treated to resist rot and insects, but it's still a wood-based product and will burn. James Hardie fiber cement is roughly 90% sand, cement, and cellulose fiber, and it doesn't support combustion the way an engineered wood panel does. With wildfire smoke and ember exposure becoming a more regular late-summer concern even here on the west side of the state, that's a difference we take seriously when we're the ones putting our name behind the work.
The Moss Factor
Whatcom County's long, wet moss season deserves its own mention. Moss and algae growth thrives on shaded siding that stays damp — under eaves, behind landscaping, on the north sides of homes near Semiahmoo Bay and further inland. On engineered wood, sustained moisture trapped under moss growth is exactly the scenario that stresses the product's weak point: the wood core underneath the protective coating. Fiber cement doesn't have an organic core for moisture to compromise in the same way, which matters a great deal on a house that might only get a good wash-down once a year.
Why We Install James Hardie Instead
James Hardie fiber cement, particularly their HZ5 formulation engineered for wet, temperate climates like ours, doesn't rely on an owner's ongoing caulk maintenance to stay structurally sound. It's non-combustible, it doesn't swell or delaminate the way wood-based products can when moisture gets past a seam, and the factory-applied ColorPlus finish is baked on rather than field-painted, which means better color retention and less chipping over time. Hardie also backs it with a strong, transferable limited warranty — useful if you sell the home down the road.
We're not saying LP SmartSide is a bad product everywhere. We're saying that for a marine climate with the rainfall, salt exposure, and moss pressure Blaine sees year after year, we'd rather install something that doesn't ask homeowners to manage a maintenance schedule just to keep the warranty intact. That's the standard we hold our own work to.
If you're weighing siding options for a home in Blaine or anywhere in Whatcom County, we're happy to walk your property, point out what's actually going on with your current siding, and talk through what makes sense for your house. Reach out for a free, no-pressure estimate — there's no obligation, just a straight answer.