Anacortes Siding What LP SmartSide Actually Is
LP SmartSide is an engineered wood siding product — strand board or oriented strand board (OSB) that's treated with resin, waxes, and zinc borate for moisture and insect resistance, then coated with a primer or factory finish. It's manufactured by Louisiana-Pacific and has been on the market for decades. It's not a bad product on paper. It cuts easily, it's lighter than fiber cement, and in dry inland climates it has a reasonable track record when installed and maintained correctly.
We get asked about it often, especially from homeowners comparing bids or coming from experience with it in other parts of the country. This page explains why, after years of installing siding in Skagit County, we standardized on James Hardie fiber cement and stopped installing engineered wood products like LP SmartSide.
The Core Issue: It's Still Wood
Underneath the resin treatment and factory coating, LP SmartSide is a wood-based product. Wood-based materials, no matter how they're engineered, share one fundamental vulnerability: they respond to moisture. They can swell, delaminate at cut edges, or degrade at seams and fastener points if water finds a way in and stays there. The treatments LP uses reduce that risk substantially compared to untreated wood, but they don't eliminate the underlying chemistry.
That distinction matters more here than in most of the country.
Why Anacortes Is a Tougher Test
Anacortes sits right on the water, surrounded by the Salish Sea, Guemes Channel, and Rosario Strait. That means three things working against any wood-based exterior product:
- Salt air: Airborne salt accelerates the breakdown of coatings and can work into seams and fastener heads faster than it would inland.
- Driving rain: Wind-driven rain off the water hits siding at an angle, not straight down, which pushes moisture into laps, joints, and butt seams that a product's design has to actively resist.
- Long moss season: Skagit County's wet, mild winters mean moss and algae have months to establish on north-facing and shaded walls. Moss holds moisture against the siding surface far longer than open air ever would.
None of these conditions are exotic — they're just the normal cost of living near the water in Western Washington. But they compound the exact weakness that engineered wood products are built to manage. In a drier, inland climate, LP SmartSide's moisture defenses rarely get tested this hard, this often, for this many months a year.
Where Failures Actually Happen
When engineered wood siding runs into trouble, it's almost never across the whole wall. It's localized, and it's almost always tied to one of a few predictable spots:
| Vulnerable Point | Why It's a Problem Here |
|---|---|
| Cut ends and field cuts | Factory edges are treated; field cuts expose raw substrate unless every cut is sealed correctly, every time |
| Butt joints and seams | Driving rain pushes water laterally into joints that aren't perfectly caulked or flashed |
| Bottom edge near grade or decks | Splash-back and snow contact hold moisture against the panel longer than the rest of the wall |
| Fastener penetrations | Each nail or screw is a potential entry point if the coating around it isn't intact |
| Shaded, moss-prone elevations | Sustained moisture contact from moss growth outlasts the product's drying cycle |
Every one of these is manageable with disciplined installation — sealing every cut edge before it goes up, flashing every joint, keeping siding off grade by code minimums. The problem is that "manageable with disciplined installation" means the product's real-world performance depends heavily on the crew, the day, and the weather during the install — not just the product spec sheet.
Installation Sensitivity Is the Real Story
This is the honest reason we walked away from LP SmartSide, more than any single failure mode: it's an unforgiving product to install correctly, and it's easy to install almost correctly and not know it until years later.
What "Correct" Actually Requires
- Sealing every single field cut with the manufacturer-specified sealant before installation, not after
- Maintaining proper clearance from grade, roofing, and decks per the manufacturer's install guide
- Using the specified fasteners at the specified spacing and depth — overdriven nails break the coating
- Back-priming or sealing any exposed cut on-site, including around penetrations for fixtures and vents
- Correct lap and joint flashing at every horizontal and vertical seam
Miss one of these on one section of wall, and that's where trouble starts — usually not in year one, but in year six or eight, after repeated wet-dry cycles. By the time it shows up, it's a repair, not a warranty conversation, because tracing a moisture failure back to a specific installation step months or years later is genuinely hard to do with certainty.
Maintenance Burden and Warranty Reality
LP SmartSide's warranty is meaningful, but like most siding warranties, it's built around proper installation and ongoing maintenance — recaulking joints, repainting on a schedule, keeping moss and vegetation off the siding, and prompt repair of any damage. That's not unique to LP; it's true of most clad wood products. But in a climate with Anacortes' rain exposure and moss pressure, that maintenance schedule tends to arrive sooner and matter more than it would in a drier region.
We don't think that's a fair trade for most homeowners here. A siding product that requires vigilant, ongoing homeowner maintenance to hold up against the exact conditions the region throws at it every winter isn't the product we want standing behind our installation work.
What We Install Instead: James Hardie Fiber Cement
We install James Hardie exclusively, and the reasoning is directly tied to everything above:
- Non-combustible: Fiber cement doesn't burn, which matters given Washington's increasing wildfire seasons and any local fire-rating considerations.
- Moisture behavior: Fiber cement is cement, sand, and cellulose fiber — it doesn't swell or delaminate the way wood-based products can when repeatedly wetted.
- ColorPlus factory finish: A baked-on, warranted finish that resists the fading and coating breakdown that salt air and UV accelerate on field-painted or field-primed products.
- Climate-engineered HZ product lines: Hardie's HZ5 designation is specifically engineered for damp, moisture-prone climates like the Pacific Northwest — it's not a generic product sold everywhere with the same spec.
- Longevity when installed to spec: Fiber cement has a long track record in coastal and marine environments specifically, not just in general use.
- Strong transferable warranty: Backed by both product performance and a warranty structure that holds up through a home sale, which matters to resale value.
Hardie isn't maintenance-free — no siding is — but the maintenance it needs (periodic washing, caulk checks, repainting on a much longer cycle if ever) is lighter and less time-sensitive than what engineered wood asks for in this climate.
A Fair Comparison, Side by Side
| Factor | LP SmartSide | James Hardie Fiber Cement |
|---|---|---|
| Base material | Engineered wood strand (OSB-based) | Fiber cement (cement, sand, cellulose) |
| Moisture response | Can swell/delaminate if compromised | Dimensionally stable when wet |
| Combustibility | Combustible (wood-based) | Non-combustible |
| Coastal/marine track record | Limited compared to inland use | Established in coastal climates |
| Install sensitivity | High — cut sealing and flashing critical | Moderate — still requires correct practice |
| Finish | Primed or factory-coated, often needs repainting | Factory-baked ColorPlus finish, longer color life |
What We Tell Homeowners Comparing Bids
If you're pricing out a siding job in Anacortes and one bid includes LP SmartSide at a lower cost than a Hardie bid, that's worth understanding clearly rather than dismissing. LP SmartSide is a legitimate, code-compliant product with a real place in the market. Our position isn't that it's a bad product everywhere — it's that we don't think it's the right product for homes exposed to this specific combination of salt air, wind-driven rain, and moss pressure, and we'd rather not install something we can't fully stand behind for the long haul.
Questions Worth Asking Any Contractor
- What siding material are you specifying, and why that one for this specific site and exposure?
- Who manufactures the product, and is it rated for coastal or marine-adjacent use?
- What does the manufacturer's install guide require at cut edges, joints, and clearances?
- What maintenance schedule does the warranty assume, and what happens if it's skipped?
- Is the warranty transferable if you sell the home?
Get an Honest Look at Your Home
Every house is different — sun exposure, tree cover, wall orientation to prevailing wind and rain all affect how any siding product performs on your specific home. We're happy to walk your property, point out where moisture and moss pressure are highest, and give you a straight answer about what we'd recommend and why. Reach out for a free, no-pressure estimate — there's a form below.