Bellingham Exterior What LP SmartSide Actually Is
LP SmartSide is an engineered wood siding product — strand-based wood fiber saturated with resins, treated with zinc borate for insect and fungal resistance, then pressed and coated with a factory primer. It's manufactured to look like traditional wood lap or panel siding, it's lighter than fiber cement, and it costs less upfront than most premium siding systems. For a lot of climates and a lot of budgets, that's a reasonable combination, and we're not going to pretend otherwise.
Bellingham Exterior Company doesn't install it. Not because it's a bad product in the abstract, but because after years of working on homes throughout Whatcom County, we made a deliberate call to standardize on one siding system — James Hardie fiber cement — and stop installing everything else, including LP SmartSide. This page explains the reasoning, honestly, so you can weigh it for your own home.
Where LP SmartSide Holds Up Well
To be fair to the product: LP SmartSide has improved substantially since the OSB siding failures of the 1990s that gave engineered wood a bad name industry-wide. The current generation uses better resin saturation and a more robust treatment process. In dry, moderate climates with good roof overhangs and diligent maintenance, it performs reasonably well for many years. It's also easier on installation crews — lighter panels, standard wood-working tools, faster nailing — which is part of why it's priced lower than fiber cement.
If we operated in a drier region with shorter wet seasons, this would be a closer call. We don't. We're in Bellingham.
Why We Don't Install It in Whatcom County
Our Wet Season Isn't Short
Whatcom County gets a long stretch of low-intensity, driving rain — not the short thunderstorm bursts you'd see in a lot of the country, but weeks of sustained damp weather pushed sideways by wind off the Sound and the Strait. Engineered wood siding is still, at its core, a wood product. Its entire performance profile depends on keeping water off the wood fiber and out of the cut edges. In a climate with occasional hard rain and long dry spells to recover in between, that's manageable. In a climate where the siding rarely gets a real chance to dry out for months at a time, the margin for error shrinks a lot.
Salt Air Along the Coast
Homes closer to Bellingham Bay and the water deal with salt-laden air that accelerates the breakdown of coatings and fasteners on a lot of siding materials. Salt air doesn't care what the substrate is made of, but it does make coating integrity and fastener corrosion resistance more important than they'd be inland. Any siding that depends on an intact factory coating to keep moisture out of a wood-based core is putting more weight on that coating here than it would somewhere drier and saltless.
Moss Season
Anyone who's scrubbed a north-facing fence or roof in this county knows the moss season is real and it's long. Moss and algae growth thrives on sustained moisture and shade, and it takes hold on siding just as readily as it does on roofing and decking. On engineered wood siding, moss buildup at the bottom of lap boards or in panel seams holds moisture directly against the material for extended periods — which is exactly the condition that causes edge swelling and delamination over time. It's a maintenance item, not a defect, but it's a maintenance item homeowners here have to actually stay on top of, season after season.
The Core Issue: It's Still Wood Fiber
Every trade-off with LP SmartSide traces back to one fact: it's an engineered wood product, and wood swells when it gets and stays wet. The zinc borate treatment protects against rot and insects, and the factory coating protects against moisture intrusion — but both protections depend on the coating staying intact and every cut edge being properly sealed at installation, forever, for the life of the siding. In our climate, that's a demanding standard to hold for 20-30 years across every seam, corner, and fastener penetration on a house.
Fiber cement doesn't have this problem because there's no wood fiber to swell in the first place. That single structural difference is the main reason we made the switch we did.
Installation Sensitivity
LP SmartSide's real-world performance is unusually dependent on installation detail work — more so than most homeowners expect from a siding upgrade:
- Every cut edge needs field-applied sealant or primer before the board goes up, not just factory-primed faces
- Butt joints and panel seams need consistent caulking maintained over the life of the product
- Ground clearance and flashing details matter more, since splash-back moisture at the base of a wall is a common failure point
- Fastener placement and nailing patterns affect how well panels resist water intrusion at penetrations
None of this is unreasonable to ask of a crew — but it means the product's real-world lifespan is only as good as the most careful (or least careful) installer on the job, on a home that will sit through 20+ Whatcom County winters. We'd rather build our standard install process around a material where installation error has a smaller downside.
Warranty Structure: What's Actually Covered
Warranty terms on engineered wood and fiber cement look similar on paper — long coverage periods, manufacturer-backed — but the practical difference shows up in what triggers a claim and how transferable it is.
| Factor | LP SmartSide (typical) | James Hardie (typical) |
|---|---|---|
| Core material | Engineered wood strand, resin-bonded | Fiber cement, non-combustible |
| Substrate warranty length | Commonly 5 years labor, longer material coverage with prorated terms | Commonly 30 years, non-prorated on many ColorPlus products |
| Finish/coating warranty | Often shorter and separate from substrate coverage | ColorPlus finish warranty often matches or nears substrate term |
| Transferability to new owner | Varies, often limited window | Typically transferable, supporting resale value |
| Sensitivity to installation error | Higher — improper sealing can void claims | Lower — no wood fiber to protect from edge exposure |
Warranty terms change over time and homeowners should always read the current documentation for any product they're considering — we're describing general patterns, not quoting a specific policy. But the pattern itself is consistent: engineered wood warranties tend to carry more exceptions tied to moisture exposure and installation, which matters more here than it would in a drier region.
Cost: The Honest Comparison
| Factor | LP SmartSide | James Hardie Fiber Cement |
|---|---|---|
| Material cost | Lower | Moderate to higher |
| Installation labor | Somewhat lower (lighter, easier to cut) | Somewhat higher (specialized blades, heavier panels) |
| Expected repainting cycle | Varies with coating and exposure | ColorPlus factory finish extends time between repaints |
| Maintenance in wet/coastal climates | Higher — edge sealing, moss management, caulk upkeep | Lower — non-combustible, dimensionally stable core |
| Long-run cost over 25-30 years | Can close the gap or exceed fiber cement once maintenance and recoating are factored in | Higher upfront, generally lower total cost of ownership locally |
The upfront price gap is real, and for some homeowners on a tight budget it's a legitimate reason to consider engineered wood elsewhere. We're simply saying that in this specific climate, the total cost of ownership math shifts more than it would somewhere drier, and we'd rather not sell a product whose long-term value proposition depends so heavily on local weather working in its favor.
What We Install Instead
Bellingham Exterior Company installs James Hardie fiber cement siding exclusively, using the HZ product lines engineered for climate zones like ours. Fiber cement is non-combustible, dimensionally stable in wet conditions since there's no wood fiber to swell or delaminate, and the ColorPlus factory finish is baked on under controlled conditions rather than depending entirely on field application to hold up over decades. Combined with a warranty structure that's typically stronger on both length and transferability, it's the system we're willing to stand behind on homes that have to handle a genuinely wet, salty, moss-prone Pacific Northwest climate for the long haul.
This isn't a knock on every homeowner who has LP SmartSide on their house today — plenty of installations perform fine, especially on homes with good overhangs and diligent upkeep. It's a statement about what we've chosen to put our name behind going forward.
If You Already Have LP SmartSide
If your Bellingham home currently has engineered wood siding, you don't need to panic or replace it early. A basic maintenance routine goes a long way:
- Inspect cut edges, seams, and butt joints annually for cracking, swelling, or gaps in caulking
- Clear moss and algae buildup at the base of walls and in shaded, north-facing areas before it holds moisture against the siding
- Check and maintain gutter and downspout function so water isn't splashing or pooling against the wall base
- Repaint or recoat on the manufacturer's recommended schedule rather than waiting for visible failure
- Address any soft spots, discoloration, or edge swelling promptly rather than letting them spread
When the time does come to replace it, that's the point at which most homeowners we talk to start asking what we'd put on the house instead — and that conversation is exactly what this page is meant to set up honestly.
Get a Straight Answer for Your House
Every home and every lot in Whatcom County sits a little differently — some are shaded and damp most of the year, some get more wind and salt exposure, some already have moss problems and some don't. If you're weighing siding options or just want an honest read on what's on your house right now, we're happy to take a look and give you a straightforward assessment. Request a free, no-pressure estimate using the form below.