Semiahmoo Siding An Honest Answer to a Question We Get Often
Homeowners in Semiahmoo and across Whatcom County ask us this regularly: "Do you install LP SmartSide?" The short answer is no. The longer answer is that we used to consider it, we've inspected plenty of it on existing homes, and we've made a deliberate decision to build our business around James Hardie fiber cement instead. This page explains that decision honestly — what LP SmartSide does well, where it struggles, and why our climate here on the water made the choice easier than it might be for a contractor working somewhere drier and calmer.
This isn't a takedown of a product that millions of feet of siding have been made from successfully. It's an explanation of a professional standard we hold ourselves to, and the trade-offs that led us there.
What LP SmartSide Actually Is
LP SmartSide is an engineered wood product. Strands of wood are bonded with resins and waxes, treated with a zinc borate additive for insect and fungal resistance, then pressed into panels, lap boards, or trim under heat. It's a legitimate engineering achievement — it's lighter than fiber cement, easier to cut and nail without specialized blades, and holds paint well when installed correctly.
Where LP SmartSide earns its reputation is impact resistance. Because it's a wood-strand composite rather than a rigid cement board, it tends to flex rather than crack under hail or a stray baseball. For builders working in hail-prone regions, that's a real selling point. Cost is another advantage — it's generally less expensive than fiber cement, both in material and labor, since it's faster to cut and hang.
Where the Trade-Offs Start
The catch with any engineered wood product is what it's made of: wood. Wood strands, resin, and wax can be manufactured to resist moisture far better than raw lumber, but they are not moisture-proof. The entire performance of the product depends on the factory sealant and edge-seal staying intact, and on every cut edge in the field being re-sealed with primer or paint before installation.
That's a big "depends on." In practice, it means the long-term durability of LP SmartSide rests almost entirely on installation discipline — every field cut sealed, every nail hole caulked, every panel-to-trim joint maintained, indefinitely, for the life of the siding. Skip a step once, and water finds the wood strands underneath. Once moisture gets past the seal, the same fibers that make the board strong and impact-resistant are also the fibers that swell, delaminate, and eventually rot.
Fiber cement doesn't have this problem in the same way, because there's no wood fiber to feed moisture damage in the first place. That single difference is the core of why we made the switch.
Why Semiahmoo's Climate Makes This a Bigger Deal
Every siding product has an easier time in a dry climate and a harder time in a wet one. Semiahmoo sits right on Semiahmoo Bay, which means three things work against wood-based siding at the same time:
- Salt air: Airborne salt accelerates the breakdown of caulking, sealants, and exposed fasteners faster than it does further inland — the same maintenance items an engineered wood product depends on to keep water out.
- Driving rain off the water: Wind-driven rain doesn't just fall on siding, it gets pushed sideways into laps, seams, and butt joints — exactly the spots where a wood-strand product's seals are doing the most work.
- A long moss season: Whatcom County's damp, mild winters keep moss and algae actively growing on north-facing and shaded siding for much of the year. Moss holds moisture directly against the surface it's growing on, which is a much worse situation for a product that can absorb water than for one that can't.
None of that means LP SmartSide will fail on every home here. Plenty of installations, kept up with diligent caulking and repainting on a strict schedule, perform fine for years. But as a contractor putting our name on a warranty and a finished home, we'd rather not build our business on a product whose success depends on a homeowner's caulk gun schedule, in a location that's harder on caulk than most.
LP SmartSide vs. James Hardie Fiber Cement
Here's a side-by-side of the factors that actually matter to a homeowner deciding between the two, based on how each product is engineered:
| Factor | LP SmartSide | James Hardie Fiber Cement |
|---|---|---|
| Core material | Wood strand composite with resin/wax binder | Cement, sand, and cellulose fiber |
| Combustibility | Combustible (wood-based) | Non-combustible |
| Moisture behavior | Can swell/delaminate if seals fail | Does not absorb and swell like wood |
| Factory finish option | Primed or pre-finished, field paint typical | ColorPlus factory baked-on finish available |
| Field cut/seam maintenance | Must be re-sealed and repainted regularly | Lower ongoing sealant dependence |
| Typical warranty | Manufacturer warranty, often prorated | Long-term, often transferable warranty |
| Impact resistance | Generally flexes well under impact | Rigid; resists dents but can chip if struck hard |
| Relative material cost | Lower | Higher, reflecting longer service life expectations |
Neither column is "bad." They're two different engineering philosophies — flexible wood composite versus rigid inert cement — and in a marine, moss-prone climate like ours, the inert option is the one we're willing to warranty.
What Correct LP Installation Actually Demands
To be fair to the product, LP SmartSide can perform well — but only with installation discipline that's easy to describe and hard to sustain for decades:
- Every field-cut end sealed with the manufacturer-specified primer before it goes on the wall, not after
- Proper starter strip, flashing, and drainage plane behind every course
- Nail placement within the manufacturer's specified zone, at correct depth, every time
- Caulk joints inspected and renewed on a regular cycle, not just when someone notices a gap
- Prompt repainting when the topcoat starts to wear, especially on sun- and rain-exposed elevations
These aren't unreasonable asks for a crew on installation day. The problem is that they're ongoing obligations for the homeowner for the life of the siding, in a climate that's actively working against caulk and paint film longevity. We'd rather sell a homeowner a product where fewer of those items are load-bearing for keeping water out of the wall.
Why We Standardized on James Hardie Instead
We install James Hardie fiber cement exclusively, and the reasons map directly to the trade-offs above:
It's non-combustible. Fiber cement doesn't burn, which matters for insurance conversations as much as safety ones.
ColorPlus factory finish. Instead of relying on field-applied paint holding up against salt air and driving rain, Hardie's factory-baked finish is engineered and warranted separately from the substrate, and holds color longer than field-applied paint typically does in coastal exposure.
Climate-engineered HZ product lines. Hardie makes HZ5 formulations specifically for wetter, colder climate zones like ours — the product is built for the moisture cycle Whatcom County actually sees, not a generic national spec.
A strong, transferable warranty that isn't contingent on a homeowner keeping up with a caulk-and-repaint schedule the way an engineered wood product's performance is.
Proven longevity when installed to spec — and installing to spec, including proper clearances, flashing, and fastening, is something we control on every job we do.
A Practical Checklist If You're Comparing Bids
Whatever siding material you end up choosing, and whoever you hire, these are worth asking about before signing anything:
- What is the core material, and how does it behave when it gets wet repeatedly over 20+ years?
- Is the finish factory-applied or field-applied, and what does the finish warranty actually cover?
- What ongoing maintenance does the manufacturer require to keep the warranty valid?
- Is the warranty transferable if you sell the home?
- Does the contractor's installation method account for wind-driven rain and moss growth specific to your site?
- What happens at the fastener and seam details — the places that fail first?
Our Position, Plainly
We don't install LP SmartSide, vinyl, Cemplank, Allura, primed spruce, or cedar. That's not because those products can't work anywhere — it's because we've chosen to put our name behind one material system, James Hardie fiber cement, that we believe holds up best against the specific combination of salt air, driving rain, and moss that Semiahmoo and the rest of Whatcom County deal with year-round. We'd rather be excellent at one thing than average across several.
If you're weighing siding options for your home, we're glad to walk through what we see on tear-offs in this area and explain why we recommend what we recommend. Reach out for a free, no-pressure estimate — we'll look at your home's specific exposure and give you a straight answer, not a sales pitch.