James Hardie Siding Seattle — Certified HZ10 Installer
Most siding fails in Seattle because of moisture. Hardie doesn’t absorb it — that’s why it works here. We install every board to Hardie’s written spec, which is what your 30-year warranty actually depends on.
WA License #GPGENGC830KD — Verify
Hardie Certified Installer
5-Star Rated
Honest Assessment — No UpsellGP General Corp installs James Hardie fiber cement across Seattle, the Eastside, and Snohomish County — HZ10 boards, ColorPlus factory finish, and HydroGap drainable WRB behind every wall. 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 James Hardie Siding?
James Hardie siding is fiber cement exterior cladding manufactured by James Hardie Industries, an Australian-founded building products company that has produced fiber cement siding for the U.S. residential market since 1990. In Seattle and across the Pacific Northwest, it’s the most-installed premium siding by volume — because fiber cement handles wind-driven rain, freeze-thaw cycles, and UV exposure better than any wood-based or vinyl alternative.
Recent Hardie projects:
- Mercer Island cedar-to-Hardie reside with R-5 insulation + Shou Sugi Ban accent →
- Bellevue modern new construction with metal coping & cedar soffit →
- Bellevue mixed Hardie lap & panel with composite accents →
Most of these Hardie projects sit on the Bellevue / Eastside corridor. See our full Bellevue siding contractor overview for permit pull-through with City of Bellevue DSD, HOA Architectural Review coordination, and Lake Washington wind-driven-rain WRB detailing.
What Is Hardie Board Made Of?
Hardie board is a composite of roughly 50% Portland cement, 30% silica sand, 10–15% cellulose fiber, and 5% water and additives, cured under heat and pressure. The cement gives it dimensional stability and fire resistance, the silica adds strength, and the cellulose fibers — kraft pulp from softwood — provide the workability of wood without the rot, insect, or moisture problems real wood has. The product is non-combustible, dimensionally stable through freeze-thaw, and warranted by James Hardie for 30 years against rotting, cracking, splitting, and delaminating.
What Is HardiePlank?
HardiePlank is the horizontal lap siding line — long planks that overlap horizontally to form the most common Seattle residential siding profile. Standard exposures are 4″, 5″, 6″, 7″, and 8.25″ face. HardiePlank ships pre-primed for field paint or factory-finished in 17 ColorPlus colors with a baked-on coating that holds 15–20 years in Seattle weather. It’s the fastest of the Hardie family to install and lowest cost per square foot — the default choice for most full re-sides we do.
What Is HardiePanel?
HardiePanel is large-format vertical sheet siding — 4′×8′, 4′×9′, or 4′×10′ panels installed vertically. Combined with 1×3 or 1×4 wood battens it creates a modern board-and-batten facade; without battens it’s a flat-panel modernist look. HardiePanel handles the load on tall walls and gables better than horizontal lap and is what you typically see on contemporary Seattle homes, ADUs, and new-build infill.
What Is HardieShingle?
HardieShingle is fiber cement shingle siding — staggered or straight-edge individual shingles for Craftsman, shingle-style, and historic-revival homes. HardieShingle costs more per square foot than HardiePlank because of per-piece handling and higher cut count, but it carries the same 30-year warranty and removes the recurring re-stain maintenance that real cedar shingles require. Common on Capitol Hill, Queen Anne, and older Mercer Island homes where the original cedar has reached end-of-life.
What Is Hardie Trim, HardieSoffit, and HardieBacker?
Hardie Trim is 5/4-thick fiber cement trim board with crisp factory edges, used for window and door trim, corner boards, frieze, and fascia. HardieSoffit is vented or unvented fiber cement soffit panels for eaves and overhangs. HardieBacker is a separate cement board product used as a tile underlayment behind kitchen and bathroom tile (not exterior siding). Together with the cladding, Hardie Trim and HardieSoffit make every visible exterior wood surface non-combustible and rot-proof — the goal on every full Hardie re-side we do.
Why “Hardiboard” or “Hardy Board” Is the Same Thing
Homeowners often search for hardiboard, hardy board, hardi siding, or hardie plank — these are all common misspellings or informal shorthand for James Hardie’s fiber cement product line. Officially the product is James Hardie® HardiePlank®, HardiePanel®, HardieShingle® with the registered marks. If you’ve been told your house has “Hardie board” siding, it’s the same thing this page covers.
Ready to talk about your project?
Free walk-through with Paul. No-pressure quote. Honest assessment of what your home needs.
Why Most Seattle Re-Sides End Up with Hardie
It’s not brand loyalty — it’s that fiber cement handles our weather better than anything else we’ve seen in 10+ years of tearing siding off houses.
150+ rainy days a year. Humidity above 75% for months. Cedar and LP SmartSide soak it up. Hardie doesn’t. Won’t swell, cup, or warp — ever.
Cement, sand, and fiber — nothing in it for rot or bugs. In shaded neighborhoods like Ravenna and Maple Leaf, we pull off wood siding and find rot clear through to the studs. Hardie on the same block? Looks like the day it went up.
ColorPlus is Hardie’s factory finish — baked on under controlled conditions. Lasts 15–20 years vs. 8–10 for field paint in Seattle’s climate.
Hardie isn’t always the answer. If you’ve got a Craftsman where the review board wants real wood, or you love Western Red Cedar — we do that too. But for most homes here, Hardie’s the smart pick.
James Hardie Product Lines We Install
We install all four Hardie lines. Most houses get a mix — lap on the body, panels on the gable, shingles as an accent.
Horizontal lap boards in smooth or cedarmill texture. Works on any style home.
Large vertical panels for a modern board-and-batten look.
The look of cedar shingles without the rot or bugs.
Twice the thickness of standard HardiePlank for real shadow lines.
The Board Matters — HZ10 vs. HZ5
Hardie makes two formulations: HZ5 for mild climates and HZ10 for places like ours that get months of rain and freezing nights.
HZ10 has additives that stop moisture from getting into the board’s core. Without HZ10, water gets in, freezes, expands, and cracks the board from the inside.
The warranty angle: put HZ5 on a Seattle house and your Hardie warranty is void. Period.
How to check: every board is stamped on the back. We verify every pallet before it goes up and photograph the stamps for your warranty file.
We order direct from Hardie — no third-party surplus, no out-of-region stock. Every board is HZ10.
Hardie Certified Installer vs. Regular Contractor — What’s Different
Anyone can buy Hardie boards and nail them to a wall. The Certified Installer certification means Hardie has trained and audited us — and it’s the only way you get the full 30-year warranty.
| Factor | Hardie Certified Installer (GP General Corp) | Standard Siding Contractor |
|---|---|---|
| Warranty Level | Full 30-year non-prorated product warranty + 15-year ColorPlus finish warranty activated automatically | Must file warranty registration manually; often only 5-year default coverage |
| Installation Training | Hardie-certified training on fastener patterns, gap spacing, flashing integration | No required manufacturer training |
| Installation Audits | Subject to periodic Hardie field audits | No manufacturer oversight |
| Material Sourcing | Direct access to Hardie distribution; verified HZ10 product | May source from secondary distributors; risk of HZ5 in HZ10 zone |
| Documentation | Photo documentation of installation details and product stamps | Typically no installation documentation beyond a basic invoice |
| Fastener Requirements | Follows Hardie spec: corrosion-resistant nails, 1” from board edges, blind-nailed | May face-nail or use incorrect fasteners |
This isn’t a marketing badge — Hardie audits us to make sure we’re still meeting their standards.
James Hardie Installation Cost — Seattle Area
Compare pricing against cedar, metal, LP SmartSide → · See pricing rates → · Hardie vs cedar head-to-head → · Fiber cement guide → · ColorPlus colors →
Installed costs depend on product line, home size, and substrate condition.
The most popular choice. HZ10 boards, WRB, flashing, and ColorPlus factory finish included.
Shingle and vertical panel options.
Premium thick-profile siding with deeper shadow lines.
Prices include material, labor, WRB, and standard flashing. Request a free assessment for a written quote.
How We Do It
Hardie doesn’t hide bad work. Cut a corner and it shows — fast.
Existing siding removed. We inspect every square foot of sheathing for dry rot, moisture damage, and structural deficiencies.
Code-compliant WRB installed with proper lapping, taped joints, and window/door flange integration.
Head flashings, kickout flashings, step flashings. We flash every transition before a single board goes up.
Blind-nailed with corrosion-resistant nails. Proper gap spacing. Every cut end sealed.
Elastomeric sealant at all transitions per Hardie spec. No over-caulking, no under-caulking.
Full walkthrough, photo documentation, and 30-year warranty registration through our Certified Installer account.
Not sure where to start?
We’ll come out, look at your siding, and give you a straight answer — even if the answer is “you don’t need us yet.”
James Hardie vs. Cedar Siding — When Each Makes Sense
We install both. Here’s an honest look at how they stack up.
| Factor | James Hardie Fiber Cement | Western Red Cedar |
|---|---|---|
| Installed Cost | $14–$20/sq ft | $20–$30/sq ft |
| Lifespan | 40–50+ years | 30–40 years |
| Moisture | Does not absorb moisture | Absorbs moisture (mitigated by priming and rainscreen) |
| Maintenance | Repaint every 15–20 years | Re-stain every 5–8 years |
| Warranty | 30-year non-prorated | None — depends on maintenance |
| Best For | Most Seattle homes | Craftsman, bungalow, character homes |
We also install LP SmartSide and metal siding.
Reviews from Seattle Hardie Projects
“Paul was straight with us from the start. Told us which walls actually needed replacing and which ones were fine. Saved us about $4,000.”
“We got three quotes. Paul’s was the only one that explained what HZ10 was and why it mattered.”
“Found rot behind our old cedar on the north side — exactly where Paul said it would be. Night and day difference.”
Read all 30 reviews on Google — 5.0 star average
James Hardie Siding Seattle — FAQ
Why hire a James Hardie Certified Installer in Seattle?
What is HZ10 and why is it required for Seattle siding?
How long does James Hardie siding last in Seattle?
How much does fiber cement siding installation cost in Seattle?
What does the James Hardie 30-year warranty actually cover?
What does HZ10 mean and why can’t I use HZ5 in Seattle?
How much does James Hardie siding cost in Seattle?
How long does a Hardie siding installation take?
ColorPlus vs. primed Hardie — which should I choose?
Do I need a permit for Hardie siding replacement in Seattle?
Can you paint James Hardie siding a different color later?
Is James Hardie siding better than LP SmartSide for Seattle homes?
How often does James Hardie siding need to be repainted?
What is the difference between HardiePlank, HardieShingle, and HardiePanel?
James Hardie Siding — Across Seattle Neighborhoods
We work across King and Snohomish Counties.
Why Hardie Certified Installation Matters More Than You Think
Not every contractor installing James Hardie is actually certified by Hardie. Many aren’t. They buy the boards, nail them up, and call it a day. The problem? Hardie’s warranty excludes damage caused by installation that doesn’t follow Hardie’s written instructions — so how your installer works decides how well that warranty holds up.
Hardie’s 30-year non-prorated warranty covers the boards against manufacturing defects. It never pays labor, and it doesn’t cover failures caused by wrong fasteners, missing clearances or skipped flashing. That’s the gap a careless install leaves you holding. Here’s the Hardie warranty in plain English.
Here’s something else most homeowners don’t know: some companies use subcontracted crews who aren’t individually certified. The company has the certification, but the crew actually nailing boards to your house might never have been trained by Hardie. The certificate hangs in the office. The guys on your scaffolding? They may have never seen it.
At GP General Corp, Paul’s crews — trusted friends and family members who’ve worked alongside him for years — are trained to Hardie spec. They know the fastener patterns, the gap spacing, the flashing integration. Paul verifies every installation personally. He’s not managing from a desk — he’s on your jobsite.
“Before you sign with any Hardie installer, ask: ‘Is the crew that will be on my house certified, or just the company?’ The answer tells you everything you need to know about how your warranty will hold up.”
Want to Know if Hardie Is Right for Your House?
Paul comes out, checks your siding, looks for moisture issues, and gives you a straight answer. Written quote, everything spelled out, no surprises.
GP General Corp · James Hardie Certified Installer · WA License #GPGENGC830KD — Verify · King & Snohomish Counties
James Hardie Seattle — see the work
Real projects from our crew — photos, specs, and the problems they solved.