Seattle Siding One Product, One Standard
We get asked about this a lot: why does a Seattle siding contractor only install one brand? It's a fair question, and the answer isn't marketing spin. After years of tearing old siding off houses in Ballard, West Seattle, Shoreline, and everywhere in between, we got tired of seeing the same failure patterns from certain products in our climate. We made a decision to standardize on James Hardie fiber cement and stop installing everything else. This page explains the reasoning, not the sales pitch.
What Our Climate Actually Does to Siding
King County doesn't get hurricanes or hard freezes, but it puts a different kind of stress on a house. We get months of low-intensity rain that finds every gap and seam. Homes near Puget Sound and the Sound-facing neighborhoods deal with salt-laden air that accelerates corrosion and finish breakdown. And nearly every yard in the region grows moss and algae on north-facing walls for a good chunk of the year, which means siding sits damp longer than it would in a drier climate. Add wood-adjacent landscaping, sprinklers hitting the lower courses, and roof runoff, and you've got a material stress test that plays out over years, not days.
Wood-based products — cedar, primed spruce, and engineered wood siding like LP SmartSide — are organic materials. Even with good treatments and coatings, they're vulnerable to moisture absorption, swelling, and rot when a coating gets breached and the wall stays wet. Vinyl doesn't rot, but it expands and contracts with temperature swings, can look flat and thin against Seattle's older housing stock, and its color is baked into a plastic that fades and chalks over time. Other fiber cement brands, like Cemplank and Allura, are chemically similar to Hardie but aren't engineered specifically for our region's moisture exposure, and we've found the factory finish and warranty backing aren't in the same league.
Why Fiber Cement, and Why This Brand
James Hardie fiber cement is a mix of cement, sand, and cellulose fiber, cured into a dense, stable board. It doesn't absorb bulk water the way wood does, it doesn't expand and contract like vinyl, and it's non-combustible — a real consideration given the wildfire smoke seasons the Pacific Northwest has seen in recent summers. It holds paint and factory finish far more consistently than wood substrates because the board itself is dimensionally stable.
Climate-Engineered Product Lines
Hardie makes region-specific formulations under its HZ5 and HZ10 designations, engineered for different moisture and freeze-thaw profiles across the country. Western Washington falls into the wetter, milder HZ5 category, and installers order the version built for it — not a generic national product. That distinction matters more here than people expect, given how many months of the year our siding stays wet.
ColorPlus Factory Finish
Instead of field-painting after installation, Hardie's ColorPlus finish is baked on at the factory in multiple coats, cured, and warrantied separately from the substrate. It resists fading and holds color consistency much better than a job-site paint job, and it means fewer repaint cycles over the life of the siding — a real cost consideration in a market where labor and material prices keep climbing.
Product Lines We Install
- HardiePlank lap siding — the most common choice for Seattle-area homes, in smooth or cedar-textured finishes
- HardiePanel vertical siding — often used for modern facades or as an accent
- HardieShingle — for homes wanting a shingle-style look without the maintenance of actual wood shingles
- HardieTrim — matched trim boards for a consistent, factory-finished look at corners and openings
The Warranty Backing It Up
Hardie backs its siding with a 30-year non-prorated limited warranty on the substrate and a separate warranty on the ColorPlus finish, both transferable to a new owner if the home sells. That's a meaningfully different commitment than what most wood or vinyl products offer, and it's part of why we're comfortable standing behind installs for the long haul.
Installation Is Not Optional Detail
Fiber cement only performs as designed when it's installed to Hardie's published specifications — correct fastening, proper clearances above grade and roof lines, flashing at every penetration, and caulking only where Hardie calls for it. A beautiful product installed loosely will still trap moisture behind it. That's why we train to the spec sheet, not habit, on every job in King County.
If you're planning a siding project and want the straight explanation of what's involved — product, cost range, and what correct installation looks like on your specific house — we're happy to walk the exterior with you. Reach out for a free, no-pressure estimate.