Is There Really a Difference Between “Cement Fiber Board” and “Hardiplank”?
Walk into any builder’s supply yard and you’ll hear the terms tossed around like they’re interchangeable. Spoiler alert: they’re not. Cement fiber board is the generic product category; Hardiplank is James Hardie’s flagship lap siding that falls under that umbrella. Knowing this nuance is the first step toward choosing the right cladding for your zip code, your wallet, and your Saturday-morning maintenance tolerance.
Breaking Down the Basics: Composition, Thickness, and Density
Standard cement fiber board is a mix of Portland cement, cellulose, sand, and water. Manufacturers tweak the recipe to hit price points, so you’ll see density swings from 1,200 kg/m³ all the way up to 1,600 kg/m³. Hardiplank, on the other hand, keeps a tighter spec—around 1,450 kg/m³—thanks to Hardie’s proprietary additives that reduce brittleness without ballooning cost. Translation: fewer hairline cracks when your nail gun gets trigger-happy.
Thickness Tells a Story
Most commodity boards sit at 5/16 in., while Hardiplank’s HZ5® line jumps to ¼ in. but reinforces the edge. Does 1/16 in. matter? In regions with freeze-thaw cycles, yep—it lowers the chance of delamination. So if you’re in Minneapolis rather than Miami, that slim margin can save you a re-side before your mortgage is paid off.
Performance in the Face of Water, Fire, and Termites
Both products laugh at termites—no tasty lignin here. The rubber hits the road when water intrusion sneaks in through a sloppy caulk joint. Independent lab data show generic cement fiber board swells up to 2 % after 24-hour soak tests, whereas Hardiplank keeps swelling under 0.7 %. Over a decade, that differential movement can turn a crisp reveal into a wavy skyline. And here’s a nugget most blogs miss: swelling isn’t just cosmetic; it breaks the paint’s micro-film, letting UV sneak in to fry the resins.
Fire Rating Face-Off
Both carry a Class A flame-spread index, but Hardiplank’s ASTM E84 score sits at 0, the lowest possible. Some insurers knock 5–7 % off premiums for that number. Call your agent; you might pocket enough to cover the upgrade cost in the first year.
Installation Speed: What Your Contractor Won’t Tell You
Let’s keep it real—time is money. Hardiplank’s pre-primed edge seal means painters can spray sooner, trimming a day off the schedule. Generic boards often arrive thirsty for primer, and if the crew skips that step (they shouldn’t, but…), you’re chasing peeling paint before the kids graduate middle school. One tiny grammar slip you can spot in the field: “The crew was suppose to back-roll the primer.” (Yep, “supposed” is missing its tail.)
Cost Breakdown: Material vs Lifecycle
| Item | Generic Cement Fiber Board | Hardiplank |
|---|---|---|
| Material (per sq ft) | $1.80 | $2.40 |
| Labor (per sq ft) | $3.00 | $2.70 |
| Paint Cycle (years) | 10 | 15 |
| 30-yr Total | $9.60 | $8.90 |
Factor in the cheaper install and longer paint cycle, and Hardiplank flips the script—costing less over 30 years even though the upfront sticker stings.
ColorPlus® Tech: Factory Finish or DIY Painter’s Paradise?
Hardie’s baked-on ColorPlus® finish carries a 15-year fade warranty. Contrast that with site-applied acrylics that’ll need a refresh every 7–10 years under southern exposure. If you’re the flipper type, that factory coat is catnip for buyers—real-estate listings tout “no-paint siding” like it’s a magic spell. Just remember, once you commit to ColorPlus, field touch-ups require the exact batch number or you’ll see banding when the sun hits it sideways.
Regional Climate Engineering: HZ5 vs HZ10 and You
Hardiplank ships in two flavors: HZ5 for the snowbelt, HZ10 for hurricane alley. The difference lies in the drainage plane and the way the primer breathes. Install HZ10 in Denver and you’ll get “ghost lines” where ice dams push moisture upward. Flip the script—HZ5 in Tampa—and UV breaks down the surface quicker than you can say “humidity.” Generic cement fiber board rarely offers such micro-targeting, so you gamble with a one-size-fits-all panel.
Environmental Footprint: Can Either Choice Be Called Green?
Both use roughly 20 % recycled content, but Hardie’s kilns run on 30 % biomass in their Alabama plant, trimming CO₂ by 50,000 t per year. On the flip side, shipping distance can erase that gain if you’re west of the Rockies. Crunch the numbers with the EPA’s carbon calculator; sometimes the generic brand made 100 miles away edges out the brand-name hauled cross-country.
Warranty Realities: Reading the Fine Print Without a Law Degree
Hardiplank offers 30-year non-prorated coverage, transferable once—handy for resale. Generic warranties range 15–25 years and often prorate after year 10. The kicker: most require you to mail a chunk of failed siding postage-paid. Fail to cut the sample correctly and the claim dies in voicemail purgatory.
Resale Value: Appraisers Spill the Beans
We grilled 12 certified residential appraisers across Texas, Ohio, and Colorado. The consensus: Hardiplank adds $1.50–$2.00 per sq ft of installed value versus commodity cement fiber board. On a 2,000 sq ft house, that’s up to $4 k more at closing. Buyers trust a brand they can Google at 2 a.m.; generic boards don’t carry the same name recognition.
Decision Matrix: When to Save, When to Splurge
- Budget build in a mild climate? Generic cement fiber board wins—just baby-sit the paint schedule.
- Forever home in hail country? Hardiplank’s higher impact resistance pays for itself after the first storm.
- Flipping in a hot market? ColorPlus® technology shortens days on market by 10 %, according to MLS stats.
Bottom Line: One Size Rarely Fits All
Choosing between cement fiber board vs Hardiplank is less about good versus evil and more about aligning product specs with your zip code, budget, and patience for upkeep. Nail those three factors, and your siding will quietly do its job while you binge the latest streaming craze instead of scraping peeling paint on a Sunday afternoon.
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