Snohomish Homeowners researching siding options in Snohomish often come across LP SmartSide and want to know how it stacks up against James Hardie fiber cement, which is the only siding product we install. This page explains what LP SmartSide is, what it does well, and the specific reasons we've made a professional decision not to install it on homes in this part of Washington. This isn't a takedown of the product — it's an honest explanation of trade-offs, written so you can make an informed decision for your own home.
What LP SmartSide Actually Is
LP SmartSide is an engineered wood siding product. At its core, it's made from wood strands — typically Southern yellow pine — bonded with resins and waxes under heat and pressure, then coated with a zinc-borate treatment for insect and fungal resistance. The panels are finished with a resin-saturated overlay and a factory primer, and the product comes in lap siding, panel siding, and trim configurations. It's a genuine engineering improvement over old-school particleboard sidings from decades past, and it holds a real place in the market as a lighter, often less expensive alternative to fiber cement.
LP has also made real strides in warranty coverage and manufacturing consistency since the product's reintroduction. For builders working on a budget, or in climates with less moisture pressure, it's a legitimate choice. Our decision not to install it isn't about doubting that engineering — it's about how the product performs specifically in Western Washington's marine climate over a 20-30 year ownership horizon.
The Core Issue: It's Still Wood
Strip away the resin treatments and zinc-borate protection, and LP SmartSide is fundamentally a wood-based product. Wood-based siding, no matter how it's engineered, shares wood's core vulnerability: it swells, shrinks, and can deteriorate when it stays wet for extended periods. Fiber cement, by contrast, is made from cellulose fiber, sand, and Portland cement — it doesn't have the same relationship with moisture that any wood product does.
This matters more in Snohomish than it would in Phoenix or Denver. Snohomish sits in a region that sees roughly 35-45 inches of annual rainfall, long stretches of driving rain off Puget Sound weather systems, and a moss season that can run from October through April on north- and west-facing walls. Wood-based siding products depend heavily on maintaining an intact factory finish and sealed cut edges to keep moisture out. Once that finish is compromised — by a scratch, a poorly sealed cut end, a nail popped slightly proud, or years of moss holding moisture against the surface — the product's core vulnerability is directly exposed to exactly the conditions this region delivers for eight months of the year.
Where Failures Actually Start
In our experience diagnosing siding problems on older homes in the area, engineered wood siding failures rarely start as a dramatic, obvious event. They start small and compound:
- Cut edges at corners, windows, and doors that weren't field-sealed with the manufacturer's specified sealant
- Nail heads driven too deep, cracking the surface coating and creating a moisture entry point
- Panel butt joints where caulking has failed after a few seasons of expansion and contraction
- Bottom edges sitting too close to grade, decking, or roofing, where splash-back keeps the material wet longer than it should be
- Moss and organic growth on shaded, north-facing walls holding moisture against the surface for weeks at a time
Every one of these is preventable with correct installation and diligent maintenance. The problem is that prevention requires permanent vigilance — a level of ongoing homeowner maintenance that most people don't sign up for when they replace their siding.
Maintenance Burden: The Real Cost Difference
The sticker price gap between LP SmartSide and James Hardie is real, and we won't pretend otherwise. But sticker price isn't the full cost of ownership. Engineered wood siding requires a maintenance cadence that fiber cement doesn't:
| Maintenance Task | LP SmartSide | James Hardie Fiber Cement |
|---|---|---|
| Repainting cycle | Every 7-10 years, sooner in wet climates | ColorPlus factory finish: 15+ years typical |
| Caulking/sealant inspection | Annual, especially at joints and cut edges | Minimal — joints designed for less sealant dependency |
| Moss/algae treatment | Regular cleaning needed to prevent moisture retention | Cleaning recommended but lower moisture-related risk |
| Touch-up after impact damage | Requires prompt sealing to prevent moisture entry | Can typically wait without urgent moisture concern |
| Clearance from grade/decking | Strict clearance required, moisture-sensitive | More forgiving, though clearance still matters |
Add up a decade of repainting, caulk inspection, and moss management, and the "savings" on installation day narrows considerably — sometimes disappears entirely once you factor in labor for repainting a two-story home.
Installation Sensitivity
LP SmartSide's long-term performance is heavily dependent on installation details being followed exactly as specified: proper fastener placement and depth, field-sealing every cut edge with the correct product, maintaining specified clearances from rooflines, decks, and grade, and using approved flashing details at every penetration. When these details are followed precisely, the product performs as designed. When they're not — and on production-built homes, corners get cut more often than homeowners realize — the consequences show up years later as swelling, delamination at edges, or soft spots that aren't visible until they've already progressed.
Fiber cement isn't installation-proof either; there's a right way and a wrong way to install James Hardie too. But the failure mode is different. A missed detail on fiber cement tends to show up as a cosmetic or localized issue. A missed detail on wood-based siding tends to show up as a moisture problem that can spread within the panel before it's visible from outside.
Fire Consideration
Washington has had increasingly active wildfire seasons in recent years, and while Snohomish County's west-side marine climate isn't the same fire risk profile as areas east of the Cascades, insurance underwriting and building codes have both been trending toward rewarding non-combustible exterior materials. James Hardie fiber cement is non-combustible. Engineered wood siding, even with its treatments, is still a wood product and carries the fire characteristics of wood. For homeowners thinking about long-term insurance costs and resale considerations, this is a factor worth weighing even outside high-fire-risk zones.
What We Install Instead, and Why
We standardized on James Hardie fiber cement siding for every home we side, and we did it based on how the product actually performs in this climate over decades, not just at installation:
Non-Combustible Core
Fiber cement doesn't burn, doesn't feed a fire, and doesn't require the same fire-related trade-offs that any wood-based product carries.
ColorPlus Factory Finish
Rather than a job-site primer that needs field-painting, Hardie's ColorPlus finish is baked on at the factory under controlled conditions, resulting in better fade resistance and a finish warranty that typically outperforms what field-applied paint on wood-based siding can offer.
HZ5 Climate Engineering
Hardie manufactures region-specific formulations (HZ10 for hot-dry climates, HZ5 for the Pacific Northwest's wetter climate) engineered around moisture exposure and freeze-thaw cycling relevant to this specific region — not a one-size-fits-all national product.
Moisture Behavior
Fiber cement's cellulose-cement composition simply doesn't swell, rot, or delaminate the way any wood product can when moisture gets past the surface. That single difference matters enormously in a place that sees the rainfall and moss pressure that Snohomish does.
Transferable Warranty
Hardie backs its product with a strong warranty structure that's transferable to a subsequent homeowner, which matters for resale value — a real consideration for anyone who might sell within the siding's lifespan.
What This Means for Your Project
If you're comparing bids and see LP SmartSide priced meaningfully below fiber cement, understand what you're comparing: a legitimate engineered wood product with real maintenance obligations against a non-combustible material engineered specifically for this region's moisture load. Both are manufactured products from reputable companies. Our decision to install only Hardie is a professional standard we've set based on installation experience and long-term callback patterns in this climate — not a claim that LP SmartSide is defective or that every installation fails.
A few questions worth asking any contractor, regardless of which siding product they're proposing:
- Will cut edges and field cuts be sealed with manufacturer-specified sealant, and can you show me that step during installation?
- What clearance from grade, decking, and roofing does the manufacturer require, and will that be met on my specific house?
- What does the warranty actually cover — material only, or labor too — and is it transferable if I sell?
- What's the expected repainting or refinishing cycle, and what does that cost over 15-20 years?
- Has this contractor dealt with moisture-related callbacks on this specific product, and how did they handle it?
Local Conditions Worth Weighing
Snohomish's location east of Puget Sound means homes here deal with a genuine wet-season workload: sustained rain events, high humidity that lingers under tree cover common in Snohomish County neighborhoods, and enough shaded northern exposures on most lots to sustain moss growth well into spring. None of that is unique to any one street or subdivision — it's the baseline reality of siding a home in this part of Western Washington. Whatever siding material you choose, it needs to be evaluated against that baseline, not against a national average climate that doesn't reflect what your walls actually face every winter.
Getting an Honest Assessment
We're happy to walk your home, look at your specific exposures, and talk through what we'd recommend and why — including where a lower-cost product might genuinely make sense for your situation, if it does. If you'd like a free, no-pressure estimate and an honest look at your options, the form below on this page is the fastest way to reach us.