Bellingham Two Different Ways to Solve the Same Problem
Bellingham homeowners have real choices when it comes to siding, and two of the most common contenders are fiber cement and engineered wood. Both were developed to fix the same old problem: solid wood siding rots, cups, and needs constant repainting. Fiber cement and engineered wood (best known by the brand name LP SmartSide) took different paths to solve it, and after years of installing both product families across Whatcom County, we made a deliberate choice to install only one. This page explains why.
What Engineered Wood Actually Is
LP SmartSide and similar engineered wood products are made from wood strands or fibers bonded with resins under heat and pressure, then coated with a wax-based moisture treatment and a factory primer. It's a genuine improvement over old-school solid wood siding — it resists splitting, holds paint reasonably well, and is lighter to install than fiber cement. For a lot of applications, it's a perfectly defensible product.
The catch is what it's still made of: wood. Strand, fiber, or board — it's an organic material, and organic materials absorb and release moisture. The wax treatment and primer are the only things standing between that wood substrate and the water. When those barriers are intact and well-maintained, the product performs. When they're compromised — a cut edge left unsealed, a nail hole, a failed caulk joint, a scratch from a ladder or a weed trimmer — moisture has a direct path into the substrate, and swelling, delamination, or soft spots can follow.
Why That Matters More Here Than in a Lot of Places
Bellingham sits right on Bellingham Bay, and Whatcom County's exterior envelopes deal with a specific combination of stressors that don't let up for long stretches of the year: salt-laden marine air, driving wind-driven rain off the Sound, and a moss and algae season that can run eight or nine months if a wall doesn't get much sun. That combination is hard on any siding, but it's particularly unforgiving of products where the performance depends on an intact moisture barrier.
- Salt air accelerates the breakdown of coatings and can work into any exposed seam or fastener point faster than in a dry inland climate.
- Driving rain pushes water sideways into laps, trim intersections, and butt joints — exactly the details where a moisture-sensitive substrate is most exposed.
- Extended moss and algae growth holds standing moisture against the siding surface for days at a time, rather than the surface drying quickly between rain events.
None of this means engineered wood siding is doomed to fail in Bellingham. Plenty of it is out there performing fine. But it means the margin for installation error and long-term maintenance neglect is thinner here than in a drier climate, and as a contractor, we'd rather not build a house's exterior around a product where a missed caulk joint five years from now becomes a moisture problem underneath.
Why We Standardized on James Hardie Fiber Cement
Fiber cement is made from cement, sand, and cellulose fibers — it's not an organic wood product, so it doesn't have the same relationship with moisture. It won't swell, delaminate, or feed rot the way a wood-based substrate can if water gets past a coating. That's the core reason we made it our standard rather than an option among several.
A few other factors matter to us as much as the moisture question:
| Factor | Why it matters in Whatcom County |
|---|---|
| Non-combustible material | Cement-based composition doesn't support flame spread the way wood-based products can |
| ColorPlus factory finish | Baked-on finish resists fading and holds up to salt air and UV better than field-applied paint |
| HZ5 climate engineering | Hardie's HZ product lines are formulated for wet, moisture-heavy regions like ours |
| Transferable warranty | Backed by a large, established manufacturer with a long track record |
None of this makes fiber cement maintenance-free or installer-proof. Fiber cement has its own installation requirements — correct fastener placement, proper clearances above grade and roof lines, sealed cut edges, and manufacturer-spec flashing details all matter. Done wrong, any siding product can fail. But the underlying material itself doesn't give moisture the same foothold that an organic substrate does, and in a climate that stays wet as long as Bellingham's does, that's the difference we care about most.
Our Bottom Line
We're not going to tell a homeowner that engineered wood siding is a bad product — it isn't, and plenty of reputable manufacturers stand behind it. What we will say is that after weighing moisture behavior, fire performance, finish durability, and long-term maintenance against what Whatcom County's marine climate actually does to an exterior wall year after year, fiber cement was the clear choice for the homes we stand behind. That's why it's the only siding system we install.
If you're weighing your own siding options for a home in Bellingham or elsewhere in Whatcom County, we're happy to walk through what we see on real houses in this climate and what it would mean for yours. Reach out for a free, no-pressure estimate using the form below.