Birch Bay Siding What LP SmartSide Is, and Why It's Popular
LP SmartSide is an engineered wood siding product — strand-based, resin-treated, and coated with a zinc borate preservative to resist fungal decay and insects. It's been on the market for decades, it's lighter than fiber cement, it's easier for some crews to cut and nail, and in the right climate, installed by the right hands, it holds up reasonably well. We're not here to tell you it's a bad product. Plenty of homes around Whatcom County wear it without major issues.
But "reasonably well in the right climate" is doing a lot of work in that sentence. Birch Bay is not always that climate. We made a business decision years ago to install only James Hardie fiber cement siding, and we think homeowners deserve the actual reasoning behind that — not a sales pitch, not a scare tactic, just the trade-offs we've watched play out on real homes near the water.
The Birch Bay Climate Factor
Birch Bay sits directly on Semiahmoo and Drayton Harbor waters, which means homes here deal with a combination most inland Whatcom County builders don't have to plan around: salt-laden marine air, driving rain that comes in sideways off Georgia Strait, and long stretches of gray, damp weather that stretch the "wet season" out for most of the year. Add in the tree cover common on many lots and you get a long moss and algae season that doesn't really let up between October and May.
Wood-based products — and that includes engineered strand products like LP SmartSide — are chemically treated to resist moisture and rot, but the treatment is a defense layer, not an immunity. Every defense layer has a service life, and every defense layer depends on the siding staying properly sealed at every cut edge, corner, and penetration for its entire life on the house.
Salt Air and Coating Longevity
Salt air doesn't just corrode metal fasteners and flashing faster than inland air does — it also accelerates the breakdown of exterior coatings and caulk. On engineered wood siding, the factory-applied coating is what keeps moisture out of the substrate. Once that coating starts to chalk, crack, or thin from years of coastal exposure, the strand-based core underneath is more exposed than most homeowners realize, and repainting on a strict cycle becomes non-negotiable rather than optional.
Driving Rain and Edge Exposure
LP SmartSide performs fine against straight-down rain. Driving rain, the kind that hits siding at an angle and drives water up under laps and into seams, is a tougher test for any wood-based product. Every field cut on a jobsite — around windows, at corners, at trim — exposes raw, unsealed material unless the crew primes and seals every single cut edge, every single time, with the specific sealants LP's warranty requires. That's a big "unless."
Where the Product Struggles in Real-World Installations
The gap between how a product performs in a lab or a manufacturer's climate testing and how it performs on an actual Birch Bay home usually comes down to installation discipline, not the product itself. That's the honest version of "why we don't install it" — it's less about LP SmartSide failing on its own terms and more about how unforgiving it is of the small shortcuts that happen on real jobsites.
- Cut edges left unprimed or unsealed become moisture entry points that aren't visible until swelling or delamination shows up months or years later.
- Caulk joints at butt seams and trim require ongoing maintenance — miss a maintenance cycle in a wet coastal climate and you're behind on protection.
- Fastener placement matters more on strand-based products; overdriven or misplaced nails can compromise the water-resistant layer.
- Moss and algae that take hold on a damp, shaded elevation hold moisture against the surface longer, which stresses the coating and any exposed seams.
- Repairs after impact damage (a ladder, a stray branch, a pressure washer held too close) expose raw substrate that needs immediate, correct resealing.
None of that makes LP SmartSide unusable. It makes it a product that demands a level of installation precision and long-term homeowner maintenance that we didn't want to guarantee on every single job, in every microclimate this stretch of coastline throws at a house.
Moss Season and Organic Growth
Whatcom County's moss season is real, and Birch Bay's tree-lined lots and marine humidity make it worse than what you'd see further inland. Moss and algae growth on wood-based siding isn't just cosmetic — it holds moisture against the surface for extended periods, which is exactly the condition an engineered wood product's coating is trying to keep away from the substrate. Fiber cement isn't immune to surface growth either, but because the core material is cement and sand rather than wood fiber, moss sitting on the surface isn't feeding moisture into a substrate that can swell, delaminate, or rot.
Installation Requirements: A Side-by-Side Look
| Factor | LP SmartSide (engineered wood) | James Hardie (fiber cement) |
|---|---|---|
| Core material | Wood strand, resin-bonded, zinc borate treated | Cement, sand, cellulose fiber — non-combustible |
| Cut-edge treatment | Must be primed/sealed on every field cut, every time | Factory-finished (ColorPlus); cut edges get touch-up, less exposure risk |
| Moisture response | Can swell or delaminate if coating fails at a seam | Does not swell, rot, or support fungal growth |
| Recoating cycle | Repainting typically needed on a set maintenance schedule | ColorPlus finish holds color far longer before repaint is needed |
| Coastal/salt air behavior | Coating and caulk breakdown accelerated by salt exposure | Cement composition is inherently unaffected by salt air |
This table isn't meant to declare one product broken and the other perfect — it's meant to show why the maintenance burden and moisture risk profile shift so much once you're a few hundred yards from saltwater with tree cover overhead.
Warranty Structure Matters Too
Warranties tell you a lot about how a manufacturer expects a product to be treated over its life. Engineered wood siding warranties are typically strong when the installation and maintenance requirements are followed to the letter — primed cuts, correct fastening, on-schedule repainting — and can be limited or voided when those steps are skipped, which happens more often than homeowners expect once the crew is long gone. James Hardie's ColorPlus and HZ product lines carry a warranty structure built around a factory-baked finish and a fiber cement substrate that doesn't depend on a homeowner keeping a repainting calendar to stay protected. We'd rather stand behind a product with a warranty that matches how homeowners actually live in their houses.
Why We Standardized on James Hardie
We install only James Hardie fiber cement siding, full stop. It's non-combustible, it doesn't rot or support insect damage, the ColorPlus factory finish holds its color for years longer than field-applied paint typically does, and Hardie's HZ5 product line is specifically engineered for climates like ours — freeze-thaw cycles, sustained moisture, and coastal exposure. When we cut it on-site, we're not gambling on whether every edge gets sealed correctly before the next rain rolls in off the bay. The material itself doesn't depend on that step the way engineered wood does.
This isn't a knock on every crew that installs LP SmartSide — plenty do it correctly and stand behind their work. It's a decision about what we're willing to put our name on, on this stretch of coastline, for the next 30-plus years a homeowner will live behind that siding.
What Correct Siding Installation Requires — A Checklist
Whatever product a homeowner chooses, here's what should be non-negotiable on a Birch Bay job:
- Proper weather-resistive barrier and rainscreen detailing behind the siding, not just house wrap and hope.
- Correct flashing at every window, door, and roof-to-wall intersection — this is where driving rain finds its way in.
- Manufacturer-specified fastener type, spacing, and placement, not "close enough."
- Every cut edge treated per manufacturer spec before it goes on the wall, not after.
- Proper clearance from grade, decks, and roof lines to keep siding out of standing moisture and splash-back.
- A written scope that names the exact product line, color system, and warranty being installed — not just "siding."
The Cost Question: Upfront vs. Lifetime
Fiber cement typically costs more upfront than engineered wood siding. That's a real trade-off and we won't pretend otherwise. But the comparison that matters is lifetime cost: repainting cycles, caulk maintenance, potential moisture repairs, and the labor to do all of that on a two-story coastal home add up over 15-20 years. For a lot of Birch Bay homeowners, especially those on lots with tree cover or closer to the water, the lower-maintenance path ends up costing less over the life of the siding, even with a higher install price on day one.
If you're weighing siding options for a Birch Bay home — whether it's storm damage, a full re-side, or new construction — we're happy to walk your property, talk through what your specific exposure looks like, and give you a straight, no-pressure estimate on James Hardie fiber cement.