Blaine Exterior What LP SmartSide Actually Is
LP SmartSide is an engineered wood siding product. At its core it's strand-based wood — similar in concept to OSB sheathing — bonded with resins, treated with a zinc borate preservative for insect and rot resistance, and finished with a wood-grain texture and factory primer or coating. It comes in lap boards, panels, and trim, and it installs a lot like traditional wood siding: nail it up, caulk the seams, paint or coat the surface.
We get asked about it regularly here in Blaine, usually by homeowners comparing bids or researching before a re-side. It's a legitimate, code-compliant siding product used all over the country, and there's nothing dishonest about a contractor who installs it well. We just don't. Here's the reasoning, product by product, so you can weigh it for your own home.
What It Gets Right
- Lighter and easier to handle on a job site than fiber cement
- Accepts fasteners and cuts more like traditional carpentry, which can speed up labor on straightforward walls
- Zinc borate treatment gives real protection against insects and fungal decay compared to untreated wood
- Lower material cost than fiber cement in most markets
Why Whatcom County's Climate Is a Hard Test for Any Wood-Based Product
Blaine sits right on the Salish Sea, a few miles from the Canadian border, and the climate here is not gentle on building exteriors. Salt-laden air off Semiahmoo Bay and Drayton Harbor accelerates corrosion on fasteners and fittings. Driving rain off the water pushes moisture sideways into wall assemblies, not just straight down. And Whatcom County's long, wet, low-sun winters create an extended moss and algae season that keeps painted and coated surfaces damp for months at a stretch.
None of that is a knock on any particular brand — it's just the environment we build in. It means the margin for error on anything wood-based (engineered or not) is smaller here than it would be in a drier inland climate. Seams, cut ends, and fastener penetrations all need to shed water perfectly, every time, for the life of the siding.
The Core Trade-Off: It's Still a Wood Product
Engineered wood strand siding is a genuine improvement over old-school solid wood lap siding — the manufacturing process and borate treatment address a lot of the old failure points. But it's still cellulose at its core, and cellulose swells when it takes on water. The vulnerable points are predictable:
- Cut ends and field cuts that don't get factory-sealed edges properly re-sealed on site
- Butt joints and seams where caulk is the only thing standing between the substrate and water intrusion
- Bottom edges near grade, decks, and porches where splash-back and standing moisture are common
- Panel penetrations — hose bibs, light fixtures, vents — where flashing has to be detailed correctly
When those details hold up, the product performs fine. When they don't — and caulk joints are exactly the kind of maintenance item that gets missed on a busy homeowner's list — moisture gets into the strand core and it swells, delaminates at the edges, or loses paint adhesion. In a marine climate with this much driving rain, that's not a hypothetical.
Installation Sensitivity
Manufacturer Instructions Are Not Optional
Engineered wood siding warranties are built around strict installation requirements: minimum clearances above grade, roofing, and decks; specific fastener spacing and type; required primer or sealant on every cut end before the piece goes up; and defined caulking practices at every seam. Skip or shortcut any of those steps and the manufacturer's warranty can be reduced or voided outright — even if the siding was installed by a licensed contractor.
That's a heavy burden to put on correct field execution, day after day, board after board, especially on a home with lots of trim, window returns, and cut angles. We'd rather not stake a homeowner's siding investment on every single joint being caulked and every cut end sealed perfectly for the life of the product.
Ongoing Maintenance Isn't a One-Time Job
Painted or coated siding needs recoating on a schedule — typically in the 5 to 10 year range depending on exposure — plus periodic caulk inspection and touch-up at seams, trim, and penetrations. On a house facing prevailing weather off the water, that maintenance window can run shorter, not longer. Skip a recoat cycle and you're not just risking a cosmetic fade — you're risking water getting behind the finish and into the substrate.
How the Warranty Structures Actually Compare
| Factor | Engineered Wood Strand Siding (LP SmartSide-type) | James Hardie Fiber Cement |
|---|---|---|
| Core material | Wood strand composite, resin-bonded | Cement, sand, and cellulose fiber — non-combustible |
| Factory finish | Primed or coated; field paint typically required or recommended on a cycle | ColorPlus baked-on finish available; no field painting needed for the warranty term |
| Repaint interval | Roughly 5-10 years depending on exposure | ColorPlus finish is warrantied well beyond that without repainting |
| Installation-dependent warranty | Yes — specific caulking, sealing, and clearance rules must be followed exactly | Yes, but the material itself is far less moisture-reactive if a detail is imperfect |
| Moisture response | Strand core can swell/delaminate if water gets past the finish | Cement composite does not swell or rot from moisture exposure |
| Typical product warranty length | Commonly in the 5-year full plus longer prorated range | Commonly 30 years, non-prorated, and transferable to one subsequent owner |
Warranty terms and finishes change over time and vary by product line, so always read the current manufacturer documents for the specific line you're comparing — this table reflects the general shape of the two categories, not a guarantee of either.
Why We Standardized on James Hardie Instead
We made a decision a while back to install one siding system, and do it well, rather than carry five product lines and split our installation standards across all of them. James Hardie fiber cement is what we chose, for a few concrete reasons that matter in this specific climate:
- Non-combustible core — cement and sand don't burn, swell, or feed insects
- Climate-engineered HZ product lines — Hardie manufactures versions of its siding formulated for specific climate zones, including the wetter Pacific Northwest conditions we build in
- ColorPlus factory finish — baked-on color that doesn't require field painting on the warranty schedule that raw or primed products do
- Moisture behavior — fiber cement doesn't swell or delaminate the way a wood-based strand product can when a joint fails
- Strong, transferable warranty — meaningful protection if you sell the home within the warranty period
We're not saying this to talk down a competitor's product — LP SmartSide is a real, code-approved siding system installed successfully across the country. We're saying it because after years of doing exterior work on homes exposed to Whatcom County's salt air, wind-driven rain, and moss season, we decided we'd rather build our reputation on one material system we trust completely than offer several and hope every install detail holds up over 20 years of Pacific Northwest weather.
What to Ask Before You Choose Any Siding Product
Whether you go with us or another contractor, and whatever siding you're considering, these are the questions worth getting straight answers to before you sign a contract:
- What does the manufacturer's warranty actually require of the installer, in writing?
- Is the finish factory-applied and warrantied, or will it need field painting on a maintenance schedule?
- What happens to the warranty if a future owner sells the house — is it transferable?
- How does this specific product respond to prolonged moisture exposure, not just occasional rain?
- Is the installer certified or specifically trained on this exact product line?
- What's the realistic maintenance schedule — caulk inspection, recoating, cleaning — over the next 15 years?
- Does the product's fire rating matter for your insurance or your specific property?
A Regional Note on Moss and Algae
One more Blaine-specific consideration: the same damp, shaded conditions that make Whatcom County green also feed moss and algae growth on exterior surfaces. Painted or coated wood-based siding gives organic growth a slightly more porous surface to take hold on over time than a hard cement composite does. It's not a dealbreaker on its own, but combined with the recoat schedule, it's one more maintenance item that adds up over a decade or two of ownership on a coastal property.
The Bottom Line
LP SmartSide isn't a bad product — it's a wood-based product asked to perform in a marine climate that's tough on wood-based products. The failure points are well understood: caulk joints, cut ends, clearances, and a repaint clock that starts the day it goes up. We'd rather install a siding system that's engineered not to have those vulnerabilities in the first place, backed by a factory finish and a warranty that doesn't hinge on every field detail being perfect for the next 20 years. That's why every siding job we take on in Blaine goes up in James Hardie.
If you're comparing siding options for a home in Blaine or anywhere in Whatcom County, we're happy to walk your property, look at your specific exposure, and give you a straight, no-pressure estimate on what a James Hardie install would look like for your house.