Sudden Valley What LP SmartSide Actually Is
LP SmartSide is an engineered wood siding product built from wood strands bonded with resin, treated with zinc borate for insect and fungal resistance, and finished with a primer or factory coating. It's a legitimate product with real advantages: it's lighter than fiber cement, easier on saw blades, and priced attractively for builders working on tight margins. A lot of reputable contractors install it, and plenty of homes wear it well for years. We're not here to tell you it's junk, because that wouldn't be honest.
We just don't put it on homes in Sudden Valley, and we want to explain exactly why, using the same standard we apply to every product we evaluate — how it performs against our specific climate over the long haul, not just how it looks on install day.
The Core Issue: It's Still Wood
Strip away the resin and the zinc borate treatment, and LP SmartSide is still an engineered wood product. Wood-based siding, no matter how it's engineered, shares one fundamental vulnerability that fiber cement doesn't: it absorbs and releases moisture, and every cut edge is a raw entry point unless it's field-treated and sealed correctly, every time, by every installer, on every job.
That's a manageable risk in a dry climate. It's a much bigger variable here. Sudden Valley sits in a Whatcom County microclimate that stacks several stressors on top of each other: long stretches of driving rain off the Puget Sound weather systems, salt-laden air working its way inland, and a moss season that can run most of the year on shaded, north-facing walls near the lake and tree line. Moss doesn't just look bad — it holds moisture directly against the siding surface for weeks at a time, which is exactly the condition wood-based products are least equipped to handle indefinitely.
Where the Trade-Offs Show Up
- Cut-edge treatment is mandatory, not optional. Every field cut exposes the strand substrate. Manufacturer specs require sealing every cut edge with an approved treatment before installation — skip one on a rake board or a trim return in a hard-to-reach spot, and that's where moisture gets in first.
- Caulking is a maintenance obligation, not a one-time task. Seams, joints, and butt ends depend on caulk staying intact to keep water out. In a climate with this much annual rainfall, caulk joints move, shrink, and eventually fail — and the warranty coverage typically expects the homeowner to keep up an inspection and recaulking schedule to stay valid.
- Swelling and edge deterioration are the known failure pattern. When moisture does get past a compromised seam or an unsealed cut, wood-based siding doesn't just get wet and dry out clean — it can swell, and the edges and corners are where that damage shows up first and is hardest to fully reverse.
- Moss and algae need active management. On the shaded lots and tree-covered lots common around Sudden Valley, moss establishes on any siding material. On a wood-based substrate, letting it sit uncleaned for a season or two isn't just cosmetic — it's sustained moisture contact against a moisture-sensitive material.
What This Means for a Homeowner's Time
None of this means LP SmartSide fails on every home. It means the product's long-term performance depends heavily on maintenance discipline that has to continue for the life of the siding — annual inspection of seams and cut edges, prompt recaulking, and staying on top of moss and moisture buildup on shaded walls. Some homeowners are glad to do that. Most people who call us want an exterior that doesn't require that level of ongoing attention, especially on a home near the lake where shade and humidity are part of the deal.
Why We Standardized on James Hardie Instead
We made a decision a while back to install one product line — James Hardie fiber cement — and stand fully behind it. Fiber cement is made from cement, sand, and cellulose fibers. It doesn't have an organic wood substrate to swell, and it's non-combustible, which matters given how many wildfire-adjacent building code conversations are happening across Washington.
Hardie's HZ5 product line is engineered specifically for climates with heavy moisture exposure — the kind of driving rain and humidity Sudden Valley sees regularly. The ColorPlus factory finish is baked on before the boards ever reach the jobsite, so the color layer isn't relying on a field-applied coat or ongoing caulk maintenance to hold up against salt air and UV. Cut edges still need proper treatment per Hardie's install spec, but the material underneath them isn't the same moisture-reactive substrate that makes wood-based siding edges the weak point.
The warranty structure reflects that confidence — it's a long, transferable warranty on the material itself, backed by a manufacturer that engineered the product for exactly this kind of Pacific Northwest weather pattern, not a generic climate assumption.
Our Bottom Line
LP SmartSide isn't a scam product, and plenty of installers use it well. But when we weigh it against the specific combination of salt air, sustained rain, and moss pressure that Sudden Valley homes deal with year-round, we don't think it's the product that lets a homeowner install siding once and stop thinking about it. That's the bar we hold every material to, and it's why we install James Hardie fiber cement exclusively.
If you're weighing your options for an upcoming siding project, we're happy to walk through what we see on homes in this area and why — no pressure, no sales pitch. Reach out for a free estimate and we'll give you a straight answer about what your home actually needs.