Bellingham Exterior An Honest Look at LP SmartSide
Homeowners in Bellingham ask us about LP SmartSide often enough that we think it deserves a straight answer instead of a sales pitch. LP SmartSide is an engineered wood siding — strand-based substrate treated with resins and zinc borate, then coated with a factory finish. It's a legitimate product, and plenty of contractors install it well. We don't. Here's why, and what we use instead.
What LP SmartSide Gets Right
To be fair to the product: it's lighter and easier to cut than fiber cement, which can speed up installation labor. It holds paint reasonably well when properly primed and sealed at every cut edge. It's less brittle than older wood-composite sidings, and the zinc borate treatment does provide real resistance to fungal decay and insects under normal conditions. For a lot of markets, it's a reasonable mid-tier choice.
Where the Trade-Offs Show Up in Whatcom County
Our issue isn't with the product in the abstract — it's with how it performs against this specific climate. Bellingham sits on Bellingham Bay, which means salt-laden air reaching siding on homes far closer to the water than most manufacturers design around. Add driving rain off the Strait of Juan de Fuca and a moss season that can run eight or nine months out of the year on shaded, north-facing walls, and you have a punishing combination for any wood-based product.
LP SmartSide is engineered wood at its core. Its long-term durability depends entirely on an unbroken factory finish and sealed edges. Every field cut, every fastener penetration, every butt joint is a spot where moisture can find its way into the substrate if caulking and sealant aren't maintained. In a dry climate, that's a minor maintenance item. In Whatcom County, where wood surfaces stay damp for extended stretches and moss holds moisture against the wall assembly, those same seams need more frequent inspection and re-sealing than most homeowners expect when they're told the product is "low maintenance."
We've also found that engineered wood siding is less forgiving of installation shortcuts than fiber cement. Gaps at trim, missed caulk lines, or fasteners driven at the wrong depth don't cause problems right away — they cause problems in year four or five, after the siding is already painted and trimmed out. By then it's a repair job, not a punch-list item.
The Maintenance Reality
Any exterior siding product needs some maintenance in this climate. The difference is what happens when maintenance gets deferred — which, realistically, it does on most homes. With engineered wood, a few seasons of neglected caulking or moss buildup at a shaded corner can mean substrate swelling or softening. With fiber cement, the same neglect mostly costs you a paint touch-up, because the substrate itself doesn't feed on moisture.
That difference matters more here than in most parts of the country. A siding product's spec sheet numbers get tested in labs, not on a bay-front lot in Bellingham with moss on the north wall by October.
What We Install Instead
We standardized on James Hardie fiber cement siding for one reason: it's the product that holds up to this specific climate with the least dependence on perfect long-term homeowner upkeep. Fiber cement is non-combustible, doesn't support fungal growth the way wood-based products can, and Hardie's ColorPlus factory finish is baked on with a warranty backing it — so you're not repainting on the same cycle you would with a field-primed wood product.
Hardie also builds climate-specific HZ product lines, and the HZ5 formulation is engineered for the wetter, harsher marine exposure we get here rather than a generic national spec. For a house facing salt air off the bay and months of damp shade, that's not a marketing detail — it's the actual difference between a wall assembly that shrugs off moisture and one that needs babysitting.
None of this means LP SmartSide is a bad product everywhere. It means that for the specific conditions Bellingham and the rest of Whatcom County throw at a wall — salt air, driving rain, and long moss seasons — we'd rather install something whose substrate isn't wood in the first place. That's a standard we hold across every job, not a pitch tailored to any one house.
Talk to Us Before You Decide
If you're comparing siding options for a home here, we're happy to walk your property, point out the spots that take the worst weather exposure, and explain honestly what each product would mean for that specific house — not a generic sales script. Reach out for a free, no-pressure estimate and we'll give you our real take.
