Fiber Cement Siding in Seattle — What It Is, What It Costs, How It’s Installed
A complete guide to fiber cement for Pacific Northwest homes. The material, the brands (James Hardie, Allura, Nichiha), the pros and cons, the installed cost, and the installation details that separate a 40-year wall from a 10-year wall.
WA License #GPGENGC830KD 
Hardie Certified Installer 
5-Star Rated 
HZ10 Spec InstallsGP General Corp installs fiber cement siding across Seattle, the Eastside, and Snohomish County — James Hardie HZ10, Allura, and Nichiha in lap, panel, and shingle, over a drainable rainscreen. James Hardie Certified Installer (verifiable on Hardie’s contractor locator), WA license GPGENGC830KD, MBAKS member, rated 5.0 on Google. Real installed rates on our pricing page; free written quote after an on-site assessment.
By Paul Gubenya — Owner, James Hardie Certified Installer · WA License #GPGENGC830KD · MBAKS Member · Rated 5.0 on Google · (425) 344-9635
What Homeowners Say
Real reviews from our Google profile — unedited, from real projects.
“We recently had Paul with GP General repair a damaged corner protector and sidings. His estimate was reasonable, his availability was timely, and his job was excellent. Our home hadn’t been re-painted in a while and the paint had considerably faded, yet he was able to match the color perfectly. Now we know who to turn to when in need of another repair work.”
“GP General replaced LP siding on our garage. Paul was very thorough when he came out to do the estimate; he listened to my concerns and was able to work out solutions on the spot. His crew did a great job and were very courteous. They also were careful about cleaning up (I didn’t find any nails!). Really happy with the job and can recommend GP General.”
“I highly recommend GP General Corp for siding replacement. We recently had our wood siding replaced with James Hardie lap siding, and Paul and his team did an excellent job.”
What Is Fiber Cement Siding?
Fiber cement is a composite siding made from Portland cement, sand, cellulose fiber, and water, mixed and pressed into planks or panels, then autoclaved to cure. The result is a board that looks and acts like wood but doesn’t share wood’s vulnerabilities — it’s non-combustible, doesn’t absorb moisture, won’t rot, and shrugs off insects.
The category was invented in 1903 (with asbestos as the original fiber, since replaced) and modernized in the 1980s when James Hardie introduced asbestos-free formulations. Today, James Hardie holds about 90% of the US fiber cement residential market. Allura (formerly CertainTeed) and Nichiha are the two credible alternatives.
In the Pacific Northwest, fiber cement has become the default high-performance siding choice over the past 15 years. The reasons are direct: it handles our 38 inches of annual rain without absorbing water, it survives freeze-thaw cycles that destroy lesser materials, and Hardie’s climate-specific HZ10 formulation is engineered for our exact moisture and temperature profile.
Fiber Cement Siding Pros and Cons
Every material has trade-offs. Here’s the honest read on fiber cement after years of installing it.
- Non-combustible. Class A fire rating — meaningful for WUI zones and insurance.
- Zero moisture absorption. Doesn’t swell, warp, or wick water. Critical in PNW.
- Immune to rot and pests. Cement-based: termites and fungi can’t process it.
- Long warranty. Hardie’s 30-year non-prorated substrate warranty + 15-year ColorPlus finish.
- Holds paint. Field paint lasts 8–12 years; ColorPlus factory finish lasts 15+.
- Aesthetic range. Lap, panel, shingle, board-and-batten, vertical, smooth, embossed wood textures.
- Resale value. Hardie is the most-recognized siding brand in residential real estate.
- Lower lifetime cost vs cedar. Cheaper upfront and dramatically less maintenance.
- Higher upfront cost than vinyl or LP. $14–$20/sf installed vs $7–$11/sf vinyl, $15–$21/sf LP.
- Heavier. Requires more careful handling and slightly slower install pace than wood.
- Dust during cutting. Crew needs proper masking, vacuum-assisted saws, and PPE for silica dust.
- Pre-finished colors are limited. ColorPlus is ~20 standard colors; custom colors require field paint.
- Unrealistic if installed wrong. Without HZ10 product, certified installer, and proper rainscreen, the warranty is voided and performance suffers.
- Brittle until installed. Boards can crack from rough handling or impact during install.
- Not the cheapest option. If pure cost is the only factor, LP SmartSide or vinyl beats it.
Is fiber cement worth it for a Seattle home?
For most homeowners in our climate, yes. The performance gap over vinyl is large enough to justify the price premium, the maintenance gap over cedar is large enough to justify the upfront cost, and the warranty is real. The exception: if you’re flipping a property in 12 months, LP SmartSide or vinyl gives you better cash-on-cash. For homeowners staying 5+ years, fiber cement pencils out.
James Hardie vs Allura vs Nichiha
The three major fiber cement brands. They make similar products with meaningful differences in warranty, installer programs, and PNW-specific formulations.
Why we install James Hardie on the vast majority of projects
Three reasons. One: the climate-specific HZ10 formulation is engineered for our region’s exact moisture and freeze-thaw profile. Allura and Nichiha don’t make a regional version. Two: the 30-year non-prorated warranty is the strongest in the category and only applies when a certified installer follows their published spec.
Three: brand recognition matters at resale. Buyers’ agents and home inspectors recognize Hardie. They don’t always recognize Allura or Nichiha, even though both are credible products. For most homeowners, that recognition translates to a faster sale and fewer questions during inspection. More on Hardie certification →
Fiber Cement Siding Cost in Seattle (2026)
Installed pricing per square foot of wall area for fiber cement projects in the Seattle market.
Includes: tear-off, dumpster, new HydroGap drainable WRB, ventilated rainscreen furring, HZ10 product, ColorPlus or primed finish, fasteners, and basic flashings. Not included: permits ($300–$900), substrate repair if rot is found ($2–$4/sf), trim/fascia/soffit add-on (12–18% of siding total). Full siding cost breakdown →
What Proper Fiber Cement Installation Looks Like
Fiber cement is only as good as the install. Here’s what we do on every project.
Recent fiber cement projects:
In Seattle, we install only HZ10 (the wet-climate Hardie formulation). HZ5 is cheaper at the supplier but voids the warranty in our climate. Confirmed in writing on every quote.
Old siding off, sheathing inspected for rot or compromised fasteners. Anything we find is documented with photos before proceeding.
HydroGap Drainable WRB by Benjamin Obdyke is our standard. The integrated drainage gap keeps any water that gets behind the siding moving down and out instead of soaking the sheathing. More on WRB →
Sill pan, head flashing with end dams, kickout flashings at every roof intersection. Done before the rainscreen furring goes up.
3/8″ vertical furring strips create the ventilated cavity that lets the wall dry. Vented top and bottom with insect mesh. Full rainscreen detail →
Per Hardie’s published spec: 1-1/4″ corrosion-resistant nails (or screws), proper edge clearances at windows and corners, butt joints staggered, 1/8″ gap at all penetrations sealed with sealant. Certified installer signature on every project.
Window, door, corner, and frieze trim using HardieTrim NT3 boards. Mitered or butt-jointed depending on architecture. Pre-painted or primed.
High-quality urethane sealant at all butt joints and trim transitions. Backer rod where the gap exceeds 1/4″. Tooled to a smooth concave bead.
Color-matched touch-up at fastener heads, butt-joint fills, and any field cuts. ColorPlus pens or matched field paint.
Fiber Cement Questions, Answered Honestly
Ready for a Fiber Cement Quote?
Free on-site assessment. Hardie HZ10 to spec. Certified installation. Written, line-itemized quote with material, finish, and installation details. No salesman, no pressure.
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