Bellingham Siding Homeowners in Bellingham often ask us why we don't install LP SmartSide or similar engineered wood siding products. It's a fair question — engineered wood has a real place in the siding market, and it isn't a bad product on paper. But after years of working on homes across Whatcom County, in a climate that sits between Puget Sound salt air, long stretches of driving rain, and a moss season that can run half the year, we standardized on James Hardie fiber cement. Here's the honest reasoning, not a sales pitch.
What Engineered Wood Siding Actually Is
LP SmartSide and comparable products are made from wood strands bonded with resin and treated with zinc borate to resist insects and decay. It's a genuine improvement over old-style hardboard siding from decades past, and it machines and installs quickly because it's still, fundamentally, a wood product. That's also its core limitation: it's wood. It expands, contracts, and absorbs moisture the way wood does, and it's combustible.
Where the Trade-Offs Show Up in This Climate
Whatcom County isn't a dry-climate market. Bellingham sees sustained wet seasons, wind-driven rain off the Sound, and salt-laden air near the water — plus enough shade and moisture on north-facing walls and tree-lined lots to grow moss on almost any exterior surface if it isn't maintained. Engineered wood siding depends heavily on an intact factory coating and properly caulked seams, joints, and cut edges to keep water out. Miss a caulk line, let a butt joint open up, or skip a maintenance cycle, and moisture can work into the strand core faster than it would with a mineral-based product. That's not a defect — it's the nature of a wood substrate, and it means the product's long-term performance depends more on ongoing homeowner upkeep than a lot of buyers realize when they choose it.
Fiber Cement's Different Starting Point
James Hardie siding is made from sand, cement, and cellulose fiber — there's no wood strand core to swell, rot, or feed the kind of organic growth that thrives in our moss season. It's non-combustible, which matters to some homeowners and insurers regardless of climate. And Hardie's ColorPlus factory finish is baked on before the boards ever leave the plant, so the color layer isn't relying on a field-applied coat to hold up against UV and driving rain the way some engineered wood systems do.
Side-by-Side Basics
| Factor | Engineered Wood (e.g. LP SmartSide) | James Hardie Fiber Cement |
|---|---|---|
| Core material | Wood strand, resin-bonded | Cement, sand, cellulose fiber |
| Combustibility | Combustible (wood-based) | Non-combustible |
| Moisture behavior | Depends on intact seams/caulk to resist swelling | Doesn't swell; moisture resistance is inherent to the material |
| Finish | Factory primer/treatment, often needs field paint maintenance | ColorPlus factory-baked finish, longer repaint intervals |
| Climate-specific engineering | General-purpose product lines | HZ5 product line engineered for wetter, colder regions like ours |
Installation Sensitivity Matters More Than People Expect
To be fair to engineered wood, a lot of its long-term problems trace back to installation and maintenance gaps rather than the product itself — unsealed end cuts, missing flashing, or caulk joints left unattended for years. The same is true in reverse for fiber cement: Hardie performs the way it's rated to perform only when it's installed to the manufacturer's specifications — correct fastener placement, proper clearances, and factory-cut edges sealed where required. We install exclusively to that spec, which is part of why we standardized on one product system instead of juggling installation details across multiple materials.
Warranty Structure
This is where the two categories tend to diverge most in practice. Fiber cement manufacturers, including James Hardie, generally back their siding with long-term, non-prorated coverage that's transferable to a new owner if the home sells. Engineered wood warranties more often step down in coverage over time and can be voided by maintenance lapses that are easy for a homeowner to miss — a cracked caulk bead, a repaint that got delayed a season or two. Neither structure is dishonest; they simply reflect how sensitive each material is to ongoing upkeep.
Why We Made the Call We Did
We're not going to tell a Bellingham homeowner that engineered wood siding is junk, because it isn't. It's a legitimate product that works fine when it's properly detailed and maintained. But when we looked at what our local climate actually does to a home over 20 or 30 years — the salt air, the driving rain, the moss — we decided we didn't want to install a product whose performance leans so heavily on perfect, sustained maintenance. James Hardie's fiber cement gave us a material whose core resistance to moisture and fire doesn't depend on a caulk line staying intact, and a warranty structure that matches that confidence. That's the whole reason we standardized on it.
If you're weighing siding options for a home in Bellingham or anywhere else in Whatcom County, we're happy to walk through what we see on local homes and why we'd recommend Hardie for yours. Reach out for a free, no-pressure estimate — no obligation, just a straight answer.