Buyer's guide
We build both. Here's the honest breakdown - cost, timeline, features, lifespan - and a three-question quiz to point you in the right direction.
Side by side
| Concrete (Gunite) | Fiberglass | |
|---|---|---|
| Cost range (NC/SC) | $95k–$400k+ | $60k–$140k |
| Build timeline | 14–22 weeks | 8–12 weeks |
| Custom shape | Unlimited | Manufactured shells only |
| Custom depth | Any depth (3'–10'+) | Up to ~5.5 ft typical |
| Integrated spa | Custom design | Only if shell includes it |
| Tanning ledge | Custom design | Only if shell includes it |
| Vanishing edge | Yes | No |
| Interior finish options | Plaster, StoneScapes, polished quartz, tile | Manufacturer gel-coat colors only |
| Daily maintenance | Slightly higher | Lower (smooth gel coat) |
| Resurface cycle | Every 15–25 yrs | Not typically resurfaced |
| Structural lifespan | 50+ yrs | 25–30 yr warranty |
| Best for | Estate builds, lake lots, custom features | Faster install, lower-maintenance family pools |
Head to head
Cost over 20 years
Fiberglass wins on day-one cost - typically $30k–$60k less than a comparable concrete build. Over 20 years the gap narrows. A concrete pool will need one re-plaster cycle ($8k–$15k) and slightly higher chemical use; a fiberglass pool may want a gel-coat refresh in year 18–22 ($12k–$18k) but uses 30–50% less chlorine. Net 20-year cost-of-ownership delta is usually $20k–$45k in fiberglass's favor - meaningful, but not the whole story.
Resale & appraisal
Both materials add real value to a Lake Norman or Charlotte-area home. Appraisers in our market typically credit 50–70% of the installed cost on a well-built pool, regardless of shell type. Concrete tends to read as "premium" on estate-tier properties ($1.5M+); fiberglass reads as "thoughtful and well-maintained" on family homes in the $600k–$1.2M range. The biggest resale lever isn't the material - it's whether the design fits the house.
Design freedom
Concrete is the answer when your lot, your view, or your taste asks for something specific - a vanishing edge over the lake, a 9-foot dive well, a spa that spills exactly the right way, a beach entry that grades into a sun shelf you sketched on a napkin. Fiberglass is the answer when one of the catalog shells already does what you want. Walk the catalog before you decide; the "perfect shell" question answers itself in 20 minutes.
Maintenance reality
A well-set fiberglass pool with a salt system runs about 2–3 hours of owner attention per month in season - skim, brush the waterline, check chemistry. A concrete pool with the same equipment runs 4–6 hours: more brushing, occasional spot treatment, more attentive chemistry to protect plaster. Both can be put on a weekly service contract for $160–$240 per month if you'd rather not touch it.
How to decide
The honest answer is that most homeowners can build either material and be thrilled. Where the decision actually breaks is on three questions, in this order:
We build both. A Rock Water consultation walks the lot, looks at the catalog, talks budget, and recommends the material that fits the answer to those three questions - not the material with the higher margin.
3-question quiz
Answer three quick questions. We'll point you in the right direction. No email required.
Question 1
Question 2
Question 3
FAQ
Both work well in NC and SC. Concrete (gunite) is the right call when you want a custom shape, depth over 6 feet, an integrated spa, vanishing edge, or a one-of-one design. Fiberglass is the right call when you want a faster install (8–12 weeks vs. 14–22), lower lifetime maintenance, and you can find a manufactured shell shape you love.
In our market, fiberglass installs typically run $60,000 to $140,000. Custom concrete pools run $95,000 to $400,000+. The price gap reflects what concrete enables: any shape, any depth, any feature.
Concrete: 14 to 22 weeks from contract to first swim. Fiberglass: 8 to 12 weeks. The fiberglass timeline assumes the shell is in stock or already in transit from the manufacturer.
Concrete shells last 50+ years structurally. Fiberglass shells carry 25–30 year manufacturer warranties on the gel coat. Both outlast the equipment package - pumps, heaters, and automation typically need replacement every 7–12 years regardless of shell type.
Modern premium fiberglass shells (we install Latham, Thursday Pools, and similar) are UV-stabilized and warrantied against gel-coat fade. Cracks are extremely rare and almost always trace back to bad installation, not the material. We back-fill with sand and water-balance during install to prevent shifting.
Yes - but only if the manufactured shell shape includes them. We can't add a custom tanning ledge to a fiberglass shell after the fact. If those features matter and the shell options don't fit, concrete is the answer.
Fiberglass wins on day-to-day maintenance. The smooth gel coat resists algae and uses less chlorine. Concrete needs slightly more brushing and occasional acid washes. Both should be on a weekly service schedule for serious users.
Concrete pools are fully resurfaceable every 15–25 years (StoneScapes/PebbleSheen typically last 20+ years). Fiberglass shells can be re-coated with specialty products but it's a workaround - most fiberglass owners replace equipment rather than refinish the shell within the warranty period.
Ready when you are
Schedule a complimentary consultation with a Rock Water designer.
