If you’re planning a new pool in the Chicago area, you’ve probably run across the debate: gunite vs shotcrete vs fiberglass. All three can create a great backyard experience, but our freeze–thaw climate exposes differences in structure, serviceability, and long-term value. Below, we explain how each is built, how they endure Midwest winters, and—critically—what ownership looks like years 5, 10, and 20. Spoiler: for custom design, easy renovations, and longevity, concrete (gunite or shotcrete) is the clear winner for most Chicagoland homes.
Quick Definitions (So We’re On the Same Page)
- Concrete pools are steel-reinforced shells created by spraying concrete over rebar:
- Gunite = dry-mix; water added at the nozzle.
- Shotcrete = pre-mixed wet concrete pumped and sprayed.
Either method delivers a structural concrete shell finished with plaster, pebble, or tile.
- Fiberglass pools are factory-molded shells craned into an excavated hole. They install quickly and feel smooth but are limited to preset shapes/sizes and are harder to renovate later.
Key point: Gunite vs shotcrete is a construction method choice within concrete. Performance depends more on engineering, crew skill, curing, and details than on which spray process is used.
Freeze–Thaw Reality Check (Chicago Conditions)
Concrete (Gunite/Shotcrete)
- Engineered for seasons: Steel schedules, expansion joints, and proper curing allow the shell and finishes to ride out temperature swings.
- Winterization: Typically winterized in place; plumbing is blown out, water level adjusted, chemistry balanced, and the pool safely covered.
- Serviceable shell: If something needs attention, concrete is easy to access, repair, refinish, and upgrade—for decades.
Fiberglass
- Shell behavior: A one-piece shell relies on correct base, backfill, and drainage to prevent movement and buoyancy in wet/high water-table conditions.
- Winterization: Also winterized in place. Full draining is generally not recommended without special measures due to float/collapse risk.
Maintenance: Let’s Bust a Common Myth
You’ll sometimes hear that “fiberglass is low maintenance.” In practice:
- Water is water. Testing, balancing, filtration, brushing, skimming, and cleaning apply to every pool type. Clear, safe water demands the same fundamentals whether your shell is concrete or fiberglass.
- Opening care differs. Because fiberglass pools are generally not drained, spring openings often rely on higher chemical doses and more aggressive rebalancing to restore water quality after winter.
- Concrete’s clean start (pro service): Concrete pools can be drained and deep-cleaned under professional oversight (site conditions permitting), pressure-washed/sanitized, and refilled with fresh water for a crisp reset. Environmentally, draining isn’t the greenest step—yet for many families it’s a cleaner, safer start to the season and part of why they prefer concrete. (Local discharge rules and groundwater conditions always apply.)
Bottom line: Routine water care is required for all pools. The idea that fiberglass “doesn’t need maintenance” is a misconception.
Renovation & Upgrades Over Time (Where Concrete Shines)
- Concrete (gunite/shotcrete):
- Easily renovated. Re-plaster, re-tile, change coping, add tanning ledges, benches, steps, or even re-shape elements.
- Finish refreshes (plaster → pebble, new tile, etc.) keep the pool looking current for decades.
- Equipment/feature upgrades (automation, lighting, water/fire features) integrate cleanly into a concrete build.
- Fiberglass:
- Limited resurfacing options. Gelcoat repairs are specialized and color-matching can be tricky; full “resurfacing” isn’t commonly offered by many local fiberglass providers.
- At its best on day one. As the finish ages, there are fewer pathways to a like-new refresh compared to concrete.
- Structural or aesthetic changes are largely constrained by the original mold.
Translation: If you care about future flexibility and keeping your pool fresh and modern, concrete gives you far more choices—and better local contractor support—to renovate rather than replace.
Customization, Timelines, and Aesthetics
- Design freedom: Concrete delivers any shape, size, or depth, integrated spas, beach entries, Baja/tanning ledges, vanishing edges—you dream it, we engineer it. Fiberglass is limited to catalog molds.
- Timeline: Fiberglass installs quickly once the shell arrives. Concrete takes longer (steel, spray, cure, tile/coping, plaster)—but the result is tailored to your yard.
- Finishes: Concrete offers premium plaster/pebble interiors and custom tile work; fiberglass offers smooth gelcoat with color choices but fewer finish options.
Gunite vs Shotcrete (Within Concrete)
Both produce excellent shells when executed correctly.
- Gunite (dry-mix): Water added at the nozzle; superb for complex custom geometry with an experienced nozzleman.
- Shotcrete (wet-mix): Factory-mixed consistency; excellent for uniform sections and production schedules.
More important than method: structural design, crew skill, curing, and inspection.
Ownership Experience & Lifespan
|
Factor |
Concrete (Gunite/Shotcrete) |
Fiberglass |
|
Weekly care (testing, cleaning) |
Required (like all pools) |
Required (like all pools) |
|
Spring opening approach |
Can be drained (pro oversight), sanitized, refilled for a fresh start* |
Generally not drained; relies on chemical rebalancing/opening treatments |
|
Renovation options |
Broad: re-plaster, tile, coping, add features |
Limited: specialized gelcoat work; full resurfacing often not locally available |
|
Long-term look |
Refreshable to “new” with finish updates |
Harder to refresh once finish fades/ages |
|
Lifespan |
Decades, with periodic refinish |
Long service life if base/backfill/drainage are perfect |
*Draining any pool must consider groundwater conditions, hydrostatic relief, and local discharge rules; leave it to pros.
Cost & Value (Big Picture)
Upfront prices can overlap depending on design and site access, but think lifecycle:
- Concrete’s renovation path and finish refresh options help protect your investment and keep the design current—especially important for premium Chicago backyards.
- Fiberglass’s speed is attractive, but limited upgrade/refresh paths can make long-term aesthetics harder to maintain.
If you want a pool that looks custom on day one and can be updated at year 10, 20, and beyond, concrete provides the most value over time.
Chicago-Smart Build Tips (Whichever You Choose)
- Engineer for soil & water: Our region’s water tables and clays require proper drainage, sub-base, and hydrostatic relief.
- Winterization details: Blow-outs, isolation valves, and a quality safety/automatic cover reduce winter headaches.
- Efficient equipment: Variable-speed pumps, LED lighting, and smart controls cut operating costs.
- Decking for seasons: Expansion joints, correct slopes, and drainage keep surfaces safe and clean.
Which Should You Choose?
- Pick concrete (gunite or shotcrete) if you want true customization, easy future renovations, a professionally clean spring start, and a structure that—when engineered and winterized properly—handles freeze–thaw with confidence.
- Choose fiberglass if a fast install and a preset shape meet your needs—and you’re comfortable with limited renovation options down the road.
Work With a Builder Who Owns the Details
Performance through Chicago winters comes down to craftsmanship and serviceability. As a family-owned builder with 17+ years in custom concrete pools and spas, Sunset Pools & Spas designs for our climate and for your future—so your pool looks incredible at opening day and is renovation-ready decades from now.
Contact Sunset Pools & Spas today for a free consultation or quote.
Gunite vs Shotcrete vs Fiberglass — Chicago Freeze–Thaw FAQs
Is gunite stronger than shotcrete?
Both can produce excellent, long-lasting shells. Design, steel, crew skill, mix control, and curing matter more than which spray method is used.
Do fiberglass pools really need less maintenance?
No. Water care is fundamentally the same across pool types. Fiberglass openings often rely on higher chemical rebalancing because the pool generally isn’t drained.
Can I drain a fiberglass pool to clean it?
Generally don’t without professional measures; shells can float or deform if groundwater is high. Most fiberglass pools are opened via chemical treatment.
Why do concrete owners like the annual deep clean?
A professional drain, sanitize, and refill (when site conditions allow) gives a fresh, clean start each season—many families prefer it for clarity and peace of mind. Sunset Pools & Spas can advise if draining is appropriate for your site.
Can fiberglass be resurfaced later?
Comprehensive resurfacing options are limited and not widely offered locally. Concrete is far easier to refinish and upgrade over time.