Mount Vernon LP SmartSide Comes Up in Almost Every Estimate
If you've been pricing siding in Mount Vernon, chances are a contractor has mentioned LP SmartSide. It's a legitimate engineered wood product, it costs less than fiber cement, and it's not the old hardboard siding that gave engineered wood a bad name decades ago. We get asked about it regularly, so we want to explain, plainly, why our crews don't install it — and why we install James Hardie fiber cement on every job instead.
What LP SmartSide Actually Is
LP SmartSide is a strand-based engineered wood product — wood fibers bonded with resin under heat and pressure, then coated with a resin-saturated overlay and treated with zinc borate to resist fungal decay and insects. It's a real improvement over the OSB siding products that failed badly in the 1990s. LP backs it with a limited warranty, it's lighter to handle than fiber cement, and it cuts and nails faster, which is part of why it's popular with builders working on tight schedules and tight budgets.
None of that is a knock on the product. For the right climate and the right maintenance commitment, it performs reasonably well. Our objection isn't that LP SmartSide is a bad product — it's that it's a wood product, and wood-based siding carries a set of long-term maintenance obligations that don't fit what we're willing to put our name behind here.
The Core Issue: It's Still Wood
Underneath the treatment and the overlay, LP SmartSide is engineered wood. That means moisture is its biggest long-term enemy. Cut edges, seams, nail penetrations, and any spot where caulking or paint has worn thin are all places where water can start working into the substrate. Once moisture gets past the surface treatment and into the wood strands, swelling, softening, and eventual delamination can follow — and by the time it's visible from the outside, the damage is usually already done underneath.
That's manageable in a dry climate with an attentive homeowner. It's a harder ask in Skagit County. Between the driving rain off the Salish Sea, the salt air near the water, and a moss season that can run most of the year on shaded, north-facing walls, this region puts sustained moisture pressure on exterior surfaces that a lot of siding products simply weren't built around. A product that depends on an intact paint film and fresh caulk to keep water out is a product that needs consistent upkeep here — not occasional upkeep.
Maintenance Is the Real Cost
LP SmartSide is field-finished, not factory-cured the way we prefer. That means the paint job — and its ongoing maintenance — falls on the homeowner or a future contractor. Caulking has to be inspected and refreshed. Cut edges have to stay sealed. Paint has to be reapplied on a real schedule, not a "whenever it looks bad" schedule, because by the time it looks bad, moisture may already be past the surface.
| Factor | LP SmartSide | James Hardie Fiber Cement |
|---|---|---|
| Base material | Engineered wood strand | Fiber cement (sand, cement, cellulose) |
| Combustibility | Combustible | Non-combustible |
| Finish | Field-painted, ongoing upkeep | Factory ColorPlus finish, no field paint for years |
| Moisture vulnerability | Higher — swelling/delamination risk at breaches | Low — cement substrate doesn't rot or swell |
| Climate-specific engineering | General-purpose | HZ product lines engineered by climate zone |
Why We Standardized on James Hardie
We install only James Hardie fiber cement, and it's not a brand preference — it's what held up to the questions we ask about every product before we'll put it on a home. Fiber cement is non-combustible, which matters in a state that takes wildfire exposure seriously even west of the Cascades. It's engineered from sand, cement, and cellulose fiber rather than wood, so it doesn't swell, rot, or delaminate the way wood-based products can when moisture gets past a seam.
Hardie's ColorPlus finish is baked on at the factory under controlled conditions, not brushed on at the jobsite, so homeowners aren't relying on field paint quality to keep the product performing for the first decade or more. And Hardie makes HZ5 product specifically engineered for wetter, freeze-thaw climates like the Pacific Northwest — the same driving rain and moss exposure we deal with in Mount Vernon and around Skagit County was actually part of the design brief, not an afterthought. Backed by a strong transferable warranty and installed to manufacturer spec, it's a system built for exactly the conditions we install in.
Our Honest Take
If a budget is tight and a homeowner understands the maintenance commitment going in, LP SmartSide isn't a scam or a trap — it's a real trade-off between upfront cost and long-term upkeep. We just aren't willing to install a product that depends on a homeowner keeping up a paint and caulk schedule for 20-plus years in a climate that doesn't make that easy. That's why every job we take on goes out with James Hardie fiber cement, installed to spec, front to back.
If you're weighing siding options for a home in Mount Vernon or anywhere in Skagit County, we're happy to walk your house, look at your exposure to weather and moisture, and give you a straight, no-pressure estimate for what Hardie fiber cement would look like on your home.