Whatcom County Two Different Approaches to the Same Problem
If you're replacing siding in Whatcom County, two products keep coming up in every conversation: James Hardie fiber cement and LP SmartSide engineered wood. Both are marketed as upgrades over old-school cedar and plywood siding, and both are genuinely better than what they replaced. But they solve the "how do we make wood-look siding last" problem in fundamentally different ways, and that difference matters a lot once you're dealing with Whatcom County's climate — salt air off Bellingham Bay and the Strait of Georgia, driving rain on the exposed sides of a house, and a moss season that can stretch from October into May.
This page lays out how each product is actually built, how each one performs over a 20-30 year window, and why we made the call to install only James Hardie. We're not going to tell you LP SmartSide is junk — it isn't. We're going to tell you what it actually is, what it takes to keep it performing, and why that trade-off didn't make sense for the homes we work on here.
What LP SmartSide Actually Is
LP SmartSide is an engineered wood product. At its core, it's strand-based wood — similar in concept to OSB (oriented strand board) — that's treated with a zinc borate preservative and coated with a resin-saturated overlay, then finished with a factory primer. The idea is to take wood's workability and lighter weight and armor it against moisture and insects better than raw cedar or plywood siding ever could.
It comes in lap siding, panel siding, and trim, and it installs similarly to traditional wood siding — nail-through installation, standard trim details, and a look that's easy for painters and trim carpenters to match to older wood-sided homes. That familiarity is part of its appeal, and it's a legitimate one.
Where LP SmartSide Holds Up
- Lighter than fiber cement, which can reduce installation labor on some jobs
- Easier to cut and work with standard woodworking tools — no silica dust control required
- Costs less per square foot than fiber cement in most markets
- Accepts field paint well, which gives more color flexibility down the road
Where the Trade-Offs Show Up
The core material is still wood. The zinc borate treatment and resin overlay are real moisture defenses, but they defend against moisture — they don't make the product immune to it. Wood-based siding depends on the coating and caulking staying intact at every cut end, joint, and fastener penetration for the life of the product. In a climate like ours, where driving rain hits west- and southwest-facing walls for months at a stretch and salt-laden air off the water accelerates the breakdown of exposed wood fiber, that's a lot of ongoing responsibility placed on paint film and sealant joints that are only as good as the crew that installed them and the maintenance schedule after that.
LP has improved the product significantly since the OSB siding failures of the 1990s (a different, unrelated product line), and their current SmartSide line carries a 5/50-year limited warranty. But it's still a wood product at its core, which means field-cut edges need to be primed and sealed on-site — every time, by every installer, on every job — or moisture finds a way in over the years.
What James Hardie Fiber Cement Actually Is
James Hardie siding is made from Portland cement, sand, and cellulose fiber, cured into a rigid, dense board. There's no wood fiber for moisture to travel through or insects to feed on, and no organic material for mold or moss to take hold of the way it can on wood-based products. It's non-combustible, which matters more every wildfire season, and it holds its shape and finish through decades of wet-dry cycling in a way engineered wood products aren't built to.
James Hardie also engineers regional product lines specifically for climate exposure. Their HZ5 line is formulated for the kind of freeze-thaw and moisture cycling the Pacific Northwest sees, which is a meaningfully different product than what gets shipped to the Southwest or Southeast.
ColorPlus Factory Finish
The other half of the equation is the finish. James Hardie's ColorPlus Technology is a baked-on, multi-coat finish applied in a controlled factory environment — not brushed or sprayed on-site. It's backed by its own 15-year finish warranty and holds color and film integrity far longer than field-applied paint, because factory-cured finishes bond and cure more consistently than anything applied outdoors on a job site, especially in our shoulder-season weather windows.
Side-by-Side: The Factors That Actually Matter
| Factor | James Hardie Fiber Cement | LP SmartSide Engineered Wood |
|---|---|---|
| Core material | Cement, sand, cellulose fiber (inorganic) | Wood strand, resin-treated (organic) |
| Combustibility | Non-combustible | Combustible (treated, but still wood) |
| Moisture behavior | Doesn't swell, rot, or delaminate | Resists moisture but depends on intact coating/sealant |
| Insect resistance | Not a food source for insects | Borate-treated, but still organic material |
| Factory finish option | ColorPlus, 15-year finish warranty | Factory-primed; topcoat is field-applied |
| Field-cut edge exposure | Requires sealing at cuts, but material itself is inert | Requires priming/sealing every cut edge, every time |
| Typical product warranty | 30-year non-prorated limited warranty | 5-year workmanship / 50-year limited warranty |
| Weight / installation | Heavier, requires fiber-cement-rated tools | Lighter, standard carpentry tools |
| Moss/algae susceptibility | Low — inorganic surface doesn't feed growth | Higher — organic substrate is more hospitable to growth if coating wears |
Why the Whatcom County Climate Tips the Scale
Every siding product on the market performs fine on a spec sheet. What separates them is 15-20 years of real exposure, and Whatcom County exposure is specific. We're dealing with:
- Salt air corrosion: Homes near Bellingham Bay, Birch Bay, and the county's western shoreline take on airborne salt that accelerates the breakdown of fasteners, coatings, and any organic siding substrate faster than an inland home would see.
- Sustained driving rain: Storms off the Strait push rain horizontally into west- and southwest-facing walls for hours at a time, which stresses every seam, butt joint, and field-cut edge on a house.
- A long moss and algae season: Our wet, mild fall-through-spring stretch is close to ideal moss-growing weather. Organic substrates give moss and algae something to root into once a coating starts to thin; inorganic fiber cement doesn't offer that foothold in the same way.
None of that makes LP SmartSide fail outright — plenty of SmartSide homes are still performing well. But it does mean the maintenance schedule (recaulking, repainting, inspecting cut edges) that keeps an engineered wood product performing is less forgiving here than it would be in a drier climate, and the cost of skipping a maintenance cycle is higher.
Maintenance Reality: What Each Product Asks of You
LP SmartSide Maintenance
- Repaint on a regular cycle (field-applied topcoats don't last as long as a factory finish)
- Inspect and re-seal caulk joints, especially around trim and penetrations, every year or two
- Check field-cut edges (around windows, corners, utility penetrations) for coating breaks
- Address any moss or algae growth before it compromises the coating
James Hardie Maintenance
- Periodic rinse to keep pollen, dust, and organic buildup from resting on the surface
- Recaulk trim joints on a normal maintenance cycle (same as any siding product)
- No repainting cycle required for the life of the ColorPlus finish warranty
The difference isn't that Hardie is "maintenance-free" — no exterior product is. It's that the maintenance burden on fiber cement is lighter and less consequential if you fall behind on it for a season, which is a realistic scenario for most homeowners.
Why We Standardized on James Hardie
We install James Hardie exclusively. We don't offer LP SmartSide, vinyl, or other engineered wood alternatives, and that's a deliberate call, not an oversight. When we looked at what actually holds up on Whatcom County homes over 20+ years — through wet winters, salt exposure near the water, and the moss pressure that hits every roofline and wall — fiber cement with a factory finish was the product that required the least from homeowners after installation and gave us the most confidence in our own workmanship standing behind it for decades, not years.
That also means our crews specialize in one installation system rather than juggling multiple product lines with different clearance requirements, fastening patterns, and flashing details. Fiber cement is less forgiving of installation shortcuts than engineered wood — it has to be installed to Hardie's published specifications (proper clearances, fastener spacing, joint treatment) to perform and to keep the warranty valid — so we'd rather be excellent at one system than adequate at several.
What to Ask Before You Choose Either Product
- What warranty actually transfers if you sell the home, and for how long?
- Who is responsible for maintaining the finish — you, or is it factory-applied and warrantied?
- What's the manufacturer's climate-specific product line for the Pacific Northwest, if one exists?
- What does the installer's own workmanship warranty cover, separate from the manufacturer's material warranty?
- Has the installer worked with this exact product on homes exposed to similar wind and rain conditions?
If you're weighing siding options for a home in Bellingham, Ferndale, Lynden, or anywhere else in Whatcom County, we're happy to walk your property, point out what your specific exposure looks like, and give you a straight answer on what it would take to re-side it right. Reach out for a free, no-pressure estimate using the form below.