Bellingham Exterior What LP SmartSide Actually Is
LP SmartSide is an engineered wood siding product made from strand board — wood fibers bonded with resin and treated with zinc borate for insect and decay resistance, then finished with a wax-based coating called SmartGuard. It's a real, code-approved product, and a lot of contractors use it. We don't. Not because it's a scam or "junk," but because after weighing how it performs in a place like Bellingham against what we ask a siding job to do for twenty-plus years, we standardized on something else. Here's the honest version of why.
What It Gets Right
Credit where it's due. LP SmartSide is lighter and easier to handle than fiber cement, which can mean faster installs and less crew fatigue. It cuts cleaner with standard wood-cutting tools, without the silica dust that comes with cutting fiber cement. It takes paint well, has decent impact resistance for a wood-based product, and it's generally less expensive than James Hardie siding up front. For some budgets and some climates, it's a reasonable choice.
Why We Don't Install It Here
It's still wood at its core
Strand board is engineered, but it's fundamentally wood fiber. Wood swells when it takes on moisture and shrinks when it dries out, and that movement is hardest on the product at cut edges, seams, and fastener penetrations — exactly the spots where a house is most exposed to weather. Whatcom County doesn't give siding a break from moisture. Between the driving rain off the Salish Sea, the marine layer that sits over Bellingham through much of the year, and a moss season that stretches long here, engineered wood siding is under near-constant pressure to hold its seal.
Maintenance has to be perfect, and stay perfect
LP SmartSide's manufacturer is upfront that every field cut, joint, and fastener needs to be primed and caulked correctly at install, and that caulking has to be inspected and maintained over the life of the siding. That's true of most siding systems to some degree, but the consequences are more serious here: if a bead of caulk fails or a cut edge goes unsealed, the substrate underneath can start to swell, delaminate, or take on rot before it's visible from the outside. In a climate with this much sustained rainfall, we don't want to be selling a homeowner a product where a small maintenance lapse can turn into a substrate problem behind the paint.
Combustibility
Fiber cement is non-combustible. Engineered wood siding, treated or not, is still a wood product and will burn. That's a meaningful difference in wildfire-adjacent building codes and insurance conversations, and it's one more reason fiber cement sits ahead of engineered wood on our list.
Salt air and coastal exposure
Bellingham sits right on the water, and homes closer to Bellingham Bay and the county's shoreline deal with a steady dose of salt-laden air. Salt exposure accelerates wear on fasteners, finishes, and any exposed seam or edge — again putting more pressure on the caulking and coating to perform flawlessly, year after year, with no gaps.
What We Install Instead
We install James Hardie fiber cement siding exclusively, in the HZ5 formulation engineered for the Pacific Northwest's wet, temperate climate. Fiber cement is made from cement, sand, and cellulose fibers — it doesn't swell with moisture the way wood-based products can, it's non-combustible, and it holds paint and color far longer than wood substrates typically do. Hardie's ColorPlus finish is baked on at the factory under controlled conditions, which gives a more consistent, durable finish than field-applied paint and comes with its own finish warranty on top of Hardie's product warranty.
None of this means Hardie is maintenance-free — no siding is. Caulking, flashing, and paint still matter on any exterior. But the failure mode we're most worried about in Whatcom County — moisture getting into the substrate through a compromised seam — is far less consequential on a cement-based product than on a wood-based one.
Our Standard
We made a call, early on, to install one product system and install it right, rather than offer several tiers and let price alone decide what goes on a house. James Hardie is that system for us. It's not that LP SmartSide can't be installed correctly — it's that we've chosen to put our warranty, our crews, and our reputation behind the product we believe holds up best against Bellingham's rain, moss, and salt air over the long haul.
If you're comparing siding options for a home in Bellingham or elsewhere in Whatcom County, we're happy to walk through what we'd recommend and why. Reach out for a free, no-pressure estimate — we'll look at your home's exposure and give you a straight answer.