Fiberglass, vinyl and gunite side by side
| Option | Fiberglass | Vinyl liner | Gunite / concrete |
|---|---|---|---|
| Pool only, small to large | $50,000–115,000 | $38,000–95,000 | $58,000–140,000 |
| Time on site (estimate) | About 2–4 weeks | About 3–5 weeks | About 4–8 weeks of work, plus curing |
| Shape and size | Factory shapes, up to about 16x40 | Any rectangle or simple freeform | Anything, with built-in spa and sun shelf |
| Wet-lot risk | Highest if emptied (lightest shell) | Liner can lift if the pool is drained | Heaviest; still needs a relief valve |
| Upkeep | Least; gelcoat resists algae | New liner every several years | Re-plaster every 10–15 years (estimate) |
| Local builders | Few; one dealer listed in Sulphur | Some | Most, including the oldest |
Our estimates for the pool, pump and filter, standard coping and start-up, built from 2025–2026 cost guides (This Old House, River Pools, Fixr) and checked against Lake Charles permit values. Checked November 2026. Deck, fence, permits and extras are separate. Your builder prices your yard.
How a fiberglass pool goes in on wet ground
The crew digs the deep end first, so water collects there. They sink a pit about a foot below the floor, fill it with clean stone and run a pump in it while they level the gravel base and set the shell (River Pools). On very wet lots, well points around the hole pull the water down. The shell is filled with water as the backfill goes in, so it's never sitting empty.
Sizes
Shells come in set shapes and sizes, from small plunge pools to about 16x40 ft, the most a truck can carry. If you want a custom shape, a beach entry or a large built-in spa, gunite is the better match.
Who installs fiberglass here
Fewer builders, so ask. San Juan Pools lists one dealer in Sulphur and one in Lake Charles (San Juan dealer list); check that any dealer is current and licensed before you sign.
Living with it
The gelcoat is smooth, so algae has less to grip in our humid summers, and you don't re-plaster. A salt system is easy on it. The one rule: call your builder before draining it for any reason.
Sources & further reading
- This Old House: inground pool cost (updated Jun 2025). Prices by type and size; add-ons
- River Pools: what a fiberglass pool really costs (Dec 2025). Base package, patio, heat pump, salt
- River Pools: hitting water during construction
- Shotcrete: dewatering in swimming pools (2025)
- San Juan Pools: Louisiana dealers
Editorial note: General planning information, not engineering or legal advice. Prices are estimates; confirm current rules with your local officials and a qualified pro.