Seattle Siding Homeowners ask us this question more than almost any other: why does a siding contractor with decades of combined crew experience install just one product line? It's a fair question, and it deserves a straight answer instead of a sales pitch. This page walks through how we got here, what we ruled out, and why James Hardie fiber cement is the only siding that leaves our trucks.
The Short Version
We install James Hardie fiber cement siding exclusively. We don't install vinyl, LP SmartSide, cedar, primed spruce, or competing fiber cement brands like Cemplank or Allura. That's not a marketing gimmick — it's an operational decision we made after years of callbacks, warranty disputes, and repair jobs on other products. Standardizing on one manufacturer means our crews install it the same correct way every time, we know exactly how it behaves in Seattle's climate, and we can stand behind the work without hedging.
What Seattle's Climate Actually Does to Siding
King County isn't a brutal climate in the way of hailstorms or hard freezes, but it is a relentless one. Siding here doesn't fail in a single dramatic event — it fails slowly, from constant low-grade exposure that never really lets up.
Salt Air and Marine Moisture
Homes closer to Puget Sound and the Sound-adjacent neighborhoods deal with a steady drift of salt-laden marine air. That air accelerates corrosion on fasteners and metal trim, and it keeps humidity levels elevated against exterior walls even on days without rain.
Driving Rain
Seattle doesn't get the heaviest annual rainfall in the country, but it gets a lot of wind-driven rain — the kind that hits siding at an angle instead of falling straight down. That matters more than total rainfall totals suggest, because driving rain forces water into laps, seams, and butt joints that a vertical rain would never reach.
The Long Moss Season
Shade, moisture, and mild temperatures give King County an extended moss and algae season — often eight months or more depending on sun exposure and tree cover. Moss holds water against a wall surface long after the rain has stopped, which is exactly the condition that rots wood-based products and stresses the paint film on anything not built to handle it.
Put those three factors together — salt air, driving rain, and a long moss season — and you have a climate that is quietly harder on siding than it looks on paper. It's not one bad storm a year; it's 300+ days of low-grade moisture pressure.
What We Ruled Out, and Why
Every product below has a legitimate place in the market. We're not calling any of them defective. We're explaining why, given our climate and our standards for a 30-plus-year installation, we stopped installing them.
Vinyl Siding
Vinyl is inexpensive and low-maintenance in the sense that it never needs paint. But it's a thin plastic product that expands and contracts significantly with temperature swings, which over time opens gaps at seams and corners — exactly where our driving rain wants to get in. It also can't be painted to refresh a faded color without specialized products, and impact damage means replacing whole panels rather than patching a section. In a marine climate, we found the long-term moisture management case for vinyl weaker than we were comfortable standing behind.
LP SmartSide
LP SmartSide is an engineered wood product — strand board with a resin-saturated overlay, not solid lumber. It's genuinely improved over old-school hardboard siding and has reasonable performance data behind it. Our concern is what happens at cut edges, fastener penetrations, and any point where the factory seal is compromised during installation or later by a homeowner hanging something on the wall. Wood-based cores are unforgiving of sustained moisture exposure, and our moss season means sustained moisture exposure is the norm, not the exception, on shaded elevations.
Cedar and Primed Spruce
Real wood siding has a look many homeowners love, and we understand the appeal. But solid wood requires a maintenance commitment — recoating, caulking, and moisture monitoring — that most homeowners don't keep up with on a real-world schedule. Once maintenance slips even one cycle in a climate with an eight-month moss season, rot can get a foothold in ways that are expensive to catch early and expensive to repair once found.
Cemplank and Allura (Competing Fiber Cement)
This one surprises people. These are fiber cement products too, and fiber cement as a category is the right call for this climate. Our decision here isn't about the core material — it's about the factory finish, the warranty structure, and the depth of climate-specific product engineering behind James Hardie's HZ5 line for the Pacific Northwest. We'd rather install one system deeply and correctly than stock parts and match colors across several product lines with different technical bulletins and different installation tolerances.
What James Hardie Gets Right
| Factor | Why It Matters Here |
|---|---|
| Non-combustible core | Portland cement, sand, and cellulose fiber — no ignition risk from the siding material itself |
| ColorPlus factory finish | Baked-on finish is more consistent and more fade- and moisture-resistant than field-applied paint |
| HZ5 climate engineering | Formulated for wet, moderate climates like ours rather than a one-size-fits-all national spec |
| Moisture behavior | Fiber cement doesn't swell, rot, or delaminate the way wood-based products can under sustained dampness |
| Transferable warranty | A material warranty that can pass to the next owner, which matters at resale in a market like Seattle's |
| Insect resistance | No food value for carpenter ants or moisture-loving pests, a real consideration under Pacific Northwest tree cover |
How Correct Installation Actually Works
Fiber cement's real-world performance depends heavily on installation, more so than most homeowners realize. A good product installed wrong will still fail early, and a lot of the "fiber cement problems" people hear about trace back to installation shortcuts rather than the material itself.
The Details That Matter
- Correct fastener type, spacing, and penetration depth — under- or over-driven nails are a leading cause of early paint failure at fastener heads
- Proper clearance at grade, decks, and roof lines so siding never sits in standing water or snow
- Rain screen or drainage plane behind the siding so incidental moisture has somewhere to go
- Correctly lapped and sealed joints, especially at butt joints where two boards meet
- Factory-cut and sealed edges wherever possible, since a cut edge is the most vulnerable point on any fiber cement board
- Flashing integration at windows, doors, and penetrations done before siding goes on, not caulked over after
We train our crews on one manufacturer's installation manual because it lets us hold every job to the same checklist. Mixing product lines means mixing installation specs, and that's where mistakes creep in.
Cost Factors Homeowners Should Understand
We won't quote fake numbers, but it's worth being honest about where the cost differences actually come from, since "Hardie costs more" is only half the story.
| Cost Factor | How It Plays Out |
|---|---|
| Material price | Fiber cement typically costs more upfront than vinyl or engineered wood per square foot |
| Installation labor | Heavier material and precision cutting mean more skilled labor hours than vinyl |
| Maintenance over time | ColorPlus finish reduces repaint cycles compared to wood or field-painted siding |
| Repair cost after damage | Individual boards can often be replaced rather than requiring full elevation replacement |
| Resale consideration | A transferable warranty and recognized brand can be a selling point in a competitive market |
The honest way to think about it: you're paying more up front for less maintenance and fewer surprises over a 30-year window, not just for a nicer-looking board.
A Standard, Not a Sales Pitch
We get that "we only install one brand" can sound like we're just pushing a product we make more margin on. The reality is closer to the opposite — a single-product standard limits what we can offer on tight budgets, and it means walking away from jobs where a homeowner specifically wants vinyl or cedar. We accept that trade-off because it lets our crews master one system instead of doing five things adequately. For homes in King County dealing with salt air, driving rain, and a long moss season year after year, we think that trade-off is the right one.
Questions to Ask Any Siding Contractor
- Which specific product line and climate zone rating are they proposing for your home?
- Do they follow the manufacturer's written installation manual, and can they explain their fastening and flashing approach?
- What does the manufacturer's warranty actually cover, and is it transferable to a future owner?
- How do they handle moisture management — rain screen, drainage plane, clearances at grade?
- Will they put their scope of work and product specification in writing before any deposit changes hands?
If you're weighing siding options for a home in Seattle or anywhere in King County, we're glad to walk through what we'd actually recommend for your specific house — sun exposure, elevation, and moisture exposure all factor in. Reach out for a free, no-pressure estimate and we'll give you a straight answer, not a script.