Sudden Valley Siding What LP SmartSide Actually Is
LP SmartSide is engineered wood siding — strand-based panels made from wood fiber bonded with resin, then treated with LP's SmartGuard process (typically zinc borate) to resist fungal decay and insects, and finished with a primer or factory coating. It's a legitimate, widely used product, and it has real advantages: it's lighter than fiber cement, easier and faster to cut and nail, and it typically costs less installed. For a lot of homes in a lot of climates, it performs fine for years.
We're not here to tell homeowners in Sudden Valley that LP SmartSide is a bad product. We're here to explain why, as a company that installs siding on homes around Lake Whatcom and throughout Whatcom County, we stopped installing it — and why we standardized on something else instead.
The Trade-Off: It's Still Wood
Underneath the treatment and the finish, LP SmartSide is an engineered wood product. That matters because wood swells, delaminates, and decays when it stays wet — and the entire performance of the product depends on water never getting behind the panel or sitting in a cut edge, joint, or fastener hole long enough to soak in.
That's manageable in a dry climate. It's a much bigger ask in Whatcom County, where homes deal with driving rain off the Sound, long stretches of damp overcast weather, and a moss season that can stretch most of the year on north-facing walls and shaded siding runs. Add the salt air that reaches homes closer to the water, and you've got conditions that specifically target the weak points of any wood-based product: cut ends, butt joints, and anywhere caulk is doing the work of keeping moisture out.
What Correct Installation Requires
- Every field cut has to be sealed with the manufacturer's specified sealer or primer before installation — not after, not "close enough."
- Joints, corners, and penetrations depend on caulk staying intact, which means ongoing inspection and re-caulking as the home ages and the caulk itself weathers.
- Proper clearance from grade, decks, and roof lines has to be maintained exactly, because standing water or splashback against an unsealed edge is where failures start.
- Any gap in that process — a missed cut edge, a shrunk bead of caulk, a gutter that overflows onto a wall — creates an entry point for moisture into a substrate that doesn't tolerate it well.
None of that is a knock on the product's engineering. It's a statement about installation risk over a 20-, 30-, or 40-year window, in a climate that gives a wood-based product very little room for error. We'd rather not put a product on a home where a single missed detail — ours or a future repair crew's — turns into a moisture problem down the line.
Warranty Reality
LP's warranty coverage is tied closely to installation being done exactly to their specifications, including edge sealing and caulking details. That's standard for engineered wood products, but it means the homeowner is carrying real responsibility for ongoing maintenance to keep that coverage meaningful — recaulking joints, watching for swelling at cuts, keeping gutters and drainage working properly. In a marine climate like ours, that maintenance schedule isn't optional upkeep; it's the thing standing between the siding and moisture intrusion.
Why We Install James Hardie Instead
James Hardie fiber cement is made from cement, sand, and cellulose fiber — there's no organic wood substrate to swell, rot, or delaminate if a cut edge gets rained on before it's sealed. It's also non-combustible, which matters to a lot of homeowners in this region given wildfire smoke and ember exposure concerns in recent Pacific Northwest fire seasons.
Hardie's ColorPlus factory finish is baked on under controlled conditions, so it holds up to UV, rain, and the kind of persistent damp that drives moss growth on north and shaded elevations. And Hardie's HZ product lines are engineered specifically for climate zones like ours — built around moisture and humidity exposure rather than a one-size-fits-all specification.
That combination — a substrate that doesn't depend on perfect caulk maintenance to stay sound, a factory finish that holds its color, and a warranty structure that isn't as sensitive to small installation lapses — is why we made fiber cement our standard rather than an option on the estimate. When a product's failure mode in our climate is more forgiving, that's the product we want on a home that has to stand up to Whatcom County winters for decades.
Our Honest Take
If you're comparing bids and one contractor is proposing LP SmartSide at a lower price, that's not automatically a red flag — it can be installed correctly and perform well. But you should ask exactly how they're handling cut-edge sealing, joint caulking, and clearance from grade, and understand what ongoing maintenance the warranty expects from you. We simply decided, after weighing those trade-offs against what our local climate does to a wood-based product over time, that we'd rather install and stand behind fiber cement.
If you're planning a siding project in Sudden Valley or anywhere else in Whatcom County and want to talk through what actually fits your home, we're happy to take a look and give you a straightforward, no-pressure estimate.