Ferndale Siding Two Different Bets on How Wood-Look Siding Should Survive the Northwest
Homeowners in Ferndale researching new siding usually land on the same two finalists: James Hardie fiber cement and LP SmartSide engineered wood. Both are marketed as upgrades over old-fashioned solid wood siding, both come primed and ready to paint, and both can look very similar once they're on a wall. But the two products are built from fundamentally different materials, and that difference matters a lot once you factor in what a Whatcom County exterior actually deals with year after year: salt air off the Strait of Georgia and Bellingham Bay, long stretches of driving rain, and a moss and mildew season that can run most of the year in shaded, north-facing spots.
We only install James Hardie fiber cement. We don't install LP SmartSide, vinyl, Cemplank, Allura, or bare cedar and spruce siding. This page explains what SmartSide does well, where it tends to struggle in our climate, and why fiber cement is the only product we're willing to put our name behind.
What LP SmartSide Gets Right
LP SmartSide is a legitimate engineered wood product, not a cheap imitation. It's made from wood strands bonded with resins, then treated with a zinc borate additive for fungal and insect resistance and coated with a resin-saturated overlay. It's lighter than fiber cement, easier on saw blades, and generally less expensive to purchase. For many parts of the country it holds up reasonably well, and plenty of installers use it successfully. We're not disputing any of that.
Where Engineered Wood Runs Into Trouble in a Marine Climate
The issue isn't the factory specs — it's how the material behaves once it's cut, nailed, caulked, and left outside in Whatcom County weather for fifteen or twenty years. A few specific concerns pushed us away from it:
- It's still wood at its core. Wood strands bonded with resin will absorb moisture faster than a cement-based product if the factory coating is ever breached — at a cut edge, a nail hole, a scratch, or a seam where caulk has failed. In a region that gets driving, wind-blown rain for months at a stretch, those breach points are exactly where water gets in.
- Field-cut edges need diligent sealing. Every cut end and corner has to be treated with manufacturer-approved sealant before installation, every time, with no exceptions. That's a lot of quality control to maintain over an entire crew and an entire job, and it's the single most common place we've seen engineered wood siding fail early on other homes in this region.
- Moss and organic growth find a foothold. Shaded, north-facing walls and anything near overhanging trees stay damp for long periods here. Wood-based substrates give moss, algae, and mildew more to grip onto and more to feed on than an inorganic cement board does, especially once the surface coating starts to wear.
- Swelling at butt joints and panel edges. Even well-installed engineered wood can show edge swelling over time in consistently wet climates, which telegraphs through the paint film as a visible ridge or dark line — a cosmetic problem that's difficult to fully reverse.
None of that means every SmartSide installation fails. It means the product's real-world performance leans hard on perfect installation and consistent maintenance, in a climate that doesn't give you much room for error.
Why Fiber Cement Is What We Install Instead
James Hardie siding is made primarily from cement, sand, and cellulose fibers — there's no wood substrate to absorb water or feed organic growth. That single difference in composition is why it holds up differently than engineered wood along the water in Whatcom County.
Non-combustible core
Fiber cement doesn't burn, which matters increasingly in the Pacific Northwest as wildfire risk and insurance underwriting both trend in the same direction.
ColorPlus factory finish
Rather than relying on field-applied paint as the primary defense, Hardie's ColorPlus finish is baked on in a controlled factory environment, which produces a more consistent, more fade- and moisture-resistant top coat than most site-applied paint jobs can match.
Climate-engineered product lines
Hardie makes HZ5 and HZ10 formulations specifically engineered for wetter, harsher climate zones — the material itself is tuned for regions like ours rather than a one-size-fits-all national spec.
Dimensional stability
Fiber cement expands and contracts far less than wood-based products with changes in moisture and temperature, which means fewer nail pops, less joint movement, and a paint film that stays intact longer.
| Factor | LP SmartSide (engineered wood) | James Hardie (fiber cement) |
|---|---|---|
| Core material | Wood strand composite | Cement, sand, cellulose fiber |
| Moisture response | Can absorb water at breached edges | Not wood-based; minimal absorption |
| Cut-edge care | Requires sealant on every field cut | Factory-finished, less field-critical |
| Fire behavior | Combustible | Non-combustible |
| Finish | Factory primer, field-painted top coat typical | Factory-baked ColorPlus finish available |
Our Standard
We made a decision a while back to stop installing anything we weren't fully confident would perform for decades on Ferndale and greater Whatcom County homes without a maintenance schedule that most homeowners won't realistically keep up with. Fiber cement, installed to Hardie's spec with the right fasteners, flashing, and clearances, is the product we're willing to stand behind. It costs more upfront than engineered wood, and we tell every homeowner that plainly — but the tradeoff is a siding system built for exactly the kind of weather this corner of Washington throws at a house.
If you're weighing your options for a siding project, we're happy to walk your home, look at your exposure to weather and moss growth, and give you a straight answer on what makes sense. Reach out for a free, no-pressure estimate — there's no obligation, just an honest look at your house.