Anacortes Siding What LP SmartSide Actually Is
LP SmartSide is an engineered wood siding built from strand board substrate — wood fibers bonded with resin under heat and pressure, then treated with a zinc borate solution for moisture and insect resistance and finished with a factory primer or pre-finished coating. It's a legitimate product that a lot of contractors install, and homeowners ask us about it often enough that we think it deserves a straight answer instead of a sales pitch.
What It Gets Right
To be fair to the product: LP SmartSide is lighter than fiber cement, easier and faster to cut and nail, and the zinc borate treatment does provide real protection against rot and insects when the product stays intact. It doesn't carry the silica dust concerns that come with cutting fiber cement, and installed crews who know the system well can turn a job quickly. None of that is a knock — it's why the product has a market.
Where the Math Changes in Skagit County
Here's the honest problem: LP SmartSide is still a wood-based product at its core. Its moisture resistance depends on the treatment and the paint film staying intact everywhere — every cut end, every nail penetration, every butt joint, every seam. As long as that seal holds, it performs. The moment it doesn't — a cut edge left unsealed, a joint that opens up, caulk that shrinks and cracks — moisture gets into the strand substrate, and OSB-based products swell and can delaminate at the exposed edge.
That's a manageable risk in a dry climate. It's a much harder bet in Anacortes. We're on the water, which means salt-laden air working on every exposed surface and fastener. We get long stretches of driving rain off the Sound, often wind-driven against south and west-facing walls. And Skagit County's marine climate gives us a moss and algae season that runs longer than most of the state, holding moisture against the siding surface for weeks at a time instead of letting it dry out between storms. That combination — salt air, sideways rain, and prolonged damp — is exactly the environment where a moisture-sensitive substrate has to perform flawlessly at every single seam, indefinitely, to avoid trouble.
The Real Issue: Installation Sensitivity and Ongoing Maintenance
LP's own installation instructions are clear that field-cut edges need to be primed or sealed before installation, and that caulked joints need to be maintained over the life of the siding. That's not a defect — it's just what the product requires to perform as designed. But it means the siding's long-term durability depends heavily on two things outside our control once we leave the job site: how perfectly every cut was sealed during install, and whether the homeowner keeps up with caulk inspection and repainting on a schedule going forward.
We install a lot of siding in a climate that doesn't forgive missed maintenance. A caulk joint that a homeowner in a drier part of the state can let slide for an extra year or two is a joint we'd be nervous about in Anacortes after one wet winter. We didn't want to sell a product, then hand the homeowner a maintenance checklist that determines whether it holds up — and we didn't want to be the ones explaining, five years later, why a substrate issue showed up at a joint nobody caulked in time.
| Factor | LP SmartSide | James Hardie Fiber Cement |
|---|---|---|
| Core material | Engineered wood strand (OSB-based) | Fiber cement (cement, sand, cellulose) |
| Moisture behavior if compromised | Can swell/delaminate at exposed edges | Does not swell or rot; non-organic |
| Combustibility | Wood-based, combustible | Non-combustible |
| Finish maintenance | Caulk joints and cut edges need ongoing upkeep | ColorPlus factory finish holds color/seal for years |
| Cut-edge handling | Requires field priming/sealing per manufacturer | Less sensitive to field-cut exposure |
Why We Standardized on James Hardie Instead
We made a business decision a while back to install only James Hardie fiber cement siding, and this is a big part of why. Hardie's core material isn't wood, so it doesn't rely on an unbroken factory treatment to resist rot — it simply isn't organic material that rot organisms can use. It's non-combustible, which matters more every year given regional wildfire smoke and ember exposure concerns. The ColorPlus factory finish is baked on and warrantied against fading and peeling, so homeowners aren't stuck on a strict repaint schedule to protect the substrate underneath. And Hardie's HZ5 product line is specifically engineered for cold, wet, marine climates like ours — which is exactly what Anacortes and the rest of Skagit County deal with.
None of this means LP SmartSide is a bad product in the abstract. It means that for the specific conditions we install in — salt air, driving rain, and a long moss season — we'd rather stand behind a material whose durability doesn't hinge on every seal holding perfectly for decades. That's the standard we hold our own installs to, and it's why Hardie is the only siding we put on homes.
If you're weighing siding options for a home in Anacortes or anywhere in Skagit County, we're happy to walk through what we see in the field and give you a straight answer — no pressure, no sales script. Reach out for a free estimate and we'll talk through what makes sense for your home.