Lynden What LP SmartSide Actually Is
LP SmartSide is an engineered wood siding product. At its core, it's strand board — wood fibers or strands bonded with resin under heat and pressure, then coated with a treated overlay (LP calls it SmartGuard) and primed at the factory. It's manufactured to look like traditional wood lap siding or panel siding, and it comes in trim, fascia, and soffit pieces that match. It's a real, engineered building product with a legitimate manufacturer behind it, and it has a place in the market. We're not here to tell you it's junk. We just don't install it, and homeowners in Lynden deserve to know why before they sign a contract.
Where It's Popular
SmartSide has built a reputation as a mid-range alternative to vinyl and a lower-cost alternative to fiber cement. It's lighter than cement board, easier on saw blades, and in dry regions with attentive owners, it can hold up reasonably well for a couple of decades. The problem isn't the product in a vacuum — it's the product in this climate, installed on this coastline, maintained by homeowners who have busy lives and don't want siding to be a recurring chore.
The Core Issue: It's Still Wood
Strip away the marketing name and SmartSide is wood-based. Wood-based siding, no matter how it's engineered or treated, shares one fundamental vulnerability that fiber cement does not: it swells, absorbs moisture, and can rot if water gets past the surface treatment and stays there. LP has improved the resin treatment and edge sealing over the years, and to their credit, the product performs better than the OSB siding failures of the 1990s that gave engineered wood a black eye industry-wide. But "better than the products that caused lawsuits thirty years ago" is a low bar, and it's not the bar we hold our own work to.
Why This Matters More in Whatcom County
Lynden sits close enough to the Salish Sea and the Fraser Valley that homes here deal with salt-tinged air, long stretches of driving rain off the water, and a moss season that can run from October through April. That combination is exactly the environment where wood-based products are tested hardest: persistent moisture, biological growth that holds water against the surface, and salt air that accelerates degradation of coatings and fasteners. A siding product's factory literature is usually written for an "average" American climate. Whatcom County isn't average — it's wetter, greener, and mossier than most of the country, and that changes the math on any wood-based product.
Where the Trade-Offs Show Up
Edge and Cut Exposure
Every piece of SmartSide gets cut on site — around windows, doors, corners, and utility penetrations. Every cut edge exposes the wood core underneath the factory-applied protective layer. Manufacturer installation instructions require field-applied sealant on every single cut edge, every time, without exception. In practice, on a real job site with dozens or hundreds of cuts, that's a lot of small steps that all have to be done correctly for the siding to perform as designed. Miss a handful of edges, and those become the first places moisture finds its way in — often years before the failure becomes visible from the ground.
Caulk and Sealant Dependency
SmartSide's water management relies more heavily on sealant joints — at trim, seams, and terminations — than a rigid mineral-based product does. Sealant is a maintenance item. It shrinks, cracks, and pulls away from the substrate over time, especially with the UV exposure and temperature swings we get across a Whatcom County year. When sealant fails on a wood-based product, the consequence isn't cosmetic — it's a direct path for water into a material that swells and can rot.
Moss and Biological Growth
North-facing walls, shaded elevations near mature trees, and anything under a roofline that doesn't get much sun are moss magnets in this part of Washington. Moss and algae hold moisture against a wall surface for extended periods. On a cement-based product, that's mostly a cleaning issue. On a wood-based product, prolonged damp contact is the exact condition that accelerates decay at the surface and, eventually, at the core.
Repainting Schedule
SmartSide comes primed, not finished, unless you pay for a factory-finished option, and even factory finishes on engineered wood typically call for repainting on a schedule — often in the 7 to 10 year range depending on exposure and color. Every repaint is scaffolding, prep, and labor cost. Over a 30-year ownership window, that adds up to a real, recurring number that many homeowners underestimate when they compare sticker prices at the time of installation.
A Side-by-Side Look
| Factor | LP SmartSide (Engineered Wood) | James Hardie (Fiber Cement) |
|---|---|---|
| Core material | Wood strand/fiber composite | Cement, sand, cellulose fiber |
| Moisture behavior | Can swell and rot if water penetrates | Does not rot; unaffected by prolonged dampness |
| Combustibility | Combustible (wood-based) | Non-combustible |
| Cut-edge treatment | Requires field sealant on every cut | Requires standard caulking; core doesn't degrade if missed |
| Finish options | Primed or factory-finished; repaint cycle applies | ColorPlus factory finish; no repaint for many years |
| Moss/algae exposure risk | Elevated — sustained dampness affects the core | Low — cleaning issue only |
| Typical warranty structure | Limited warranty, often prorated | Long-term, non-prorated on most Hardie products |
Why We Standardized on James Hardie Instead
We install James Hardie fiber cement siding exclusively, and it's not because of a sponsorship or a rebate program — it's because after years of tear-offs and repair calls on wood-based and vinyl siding across the region, fiber cement is what consistently holds up in this specific climate without demanding a maintenance relationship from the homeowner. Hardie's HZ5 product line is engineered specifically for cold, wet, high-moisture climates like ours. It's non-combustible, which matters more every year as wildfire smoke and ember exposure become a bigger part of Pacific Northwest summers. The ColorPlus factory finish is baked on under controlled conditions, which means better fade resistance and adhesion than field-applied paint, and it comes with its own finish warranty layered on top of the product warranty.
What Correct Installation Still Requires
To be clear, Hardie siding isn't magic and it isn't maintenance-free in the sense of "never think about it again." It still needs correct flashing details, proper clearance from grade and roof lines, and installation to the manufacturer's specifications to perform the way it's designed to. The difference is that when installation is done right, the core material itself isn't the weak link — you're not fighting the base material's own tendency to absorb water and decay. That's a meaningfully different starting point for a 30-plus year exterior investment.
What This Means for Your Project
If you already have SmartSide on your home and it's performing fine, we're not telling you to panic or rip it out early. Well-installed SmartSide with disciplined maintenance can serve a homeowner reasonably well for years. What we are telling you is that if you're planning new siding, a full replacement, or you're comparing bids that include SmartSide as a lower-cost option, you should go in with clear eyes about what that price difference is actually buying — and what it's asking of you in upkeep over the life of the product.
Questions Worth Asking Any Contractor Offering Engineered Wood
- Who is responsible for sealing every cut edge, and how is that verified before the wall is closed up?
- What's the manufacturer's clearance requirement from grade, decks, and roof lines, and will the site conditions actually allow it?
- What does the warranty actually cover, and is it prorated after a certain number of years?
- What's the realistic repaint or recoat interval for this specific product and finish?
- How does the manufacturer's climate zone guidance apply to Whatcom County specifically?
Our Honest Bottom Line
LP SmartSide is a legitimate product that has earned a place in the market, and we understand why it's attractive on price. But we build our business on siding that we're comfortable standing behind for decades in a climate that includes salt air, driving rain, and months of moss season every single year. For us, that means fiber cement, and specifically James Hardie's engineered lines, not because we're chasing a brand name, but because it's the material that keeps showing up in good condition on the homes we've installed it on years later — without the cut-edge sealing, biological growth exposure, and repaint cycle that come with wood-based siding in this part of Washington.
If you're weighing your siding options for a home in Lynden or anywhere in Whatcom County, we're happy to walk your property, look at your exposure, sun, and moisture conditions, and give you a straight answer about what will actually hold up. Reach out for a free, no-pressure estimate — there's no obligation, and you'll get an honest read on your specific situation, not a sales pitch.