Gunite (sprayed concrete)
A rebar cage is tied in the excavated pool shape, then a concrete-mix slurry is pneumatically sprayed over the rebar. The result is a fully custom, monolithic concrete shell. After curing, the shell is tiled at the waterline, the interior is plastered (or pebble-finished), and the surrounding decking is installed.
- Build timeline: 8-16 weeks from excavation to fill.
- Customization: Total. Any shape, depth, attached spa, vanishing edge, beach entry, sun shelf — all possible.
- Cost: $70K-$200K+ depending on size + features.
- Gross margin (builder): 25-40% on the full project.
- Lifespan: 25-50+ years with periodic re-plastering (every 10-15 years).
Fiberglass
A pre-manufactured fiberglass shell is trucked to the site (sometimes by crane) and lowered into a prepared excavation. Plumbing is hooked up, the surrounding area is backfilled with sand or gravel, and decking is poured around the perimeter.
- Build timeline: 1-3 weeks from excavation to fill.
- Customization: Limited to manufacturer's shell catalog. Most major manufacturers offer 20-60 models.
- Cost: $50K-$120K depending on size + decking + features.
- Gross margin (builder): 30-45% on the full project.
- Lifespan: 25-50+ years with minimal interior maintenance (gel coat may need refinishing at 20-25 years).
Tradeoffs side-by-side
- Speed: Fiberglass wins decisively. 1-3 weeks vs 8-16 weeks.
- Cost: Fiberglass typically 10-25% cheaper.
- Customization: Gunite wins. Any shape, premium features possible.
- Surface feel: Fiberglass wins. Smooth gel coat is gentler on swimmers' feet than concrete-plaster.
- Chemical maintenance: Fiberglass wins. Less chemical drift; better algae resistance.
- Resale value: Custom gunite often appraises higher in premium markets; well-built fiberglass holds value in mid-market neighborhoods.
Which builders run which
Most established pool building operations specialize in one method but offer the other as a secondary product line. The economics are different enough that crews + project management workflows don't perfectly transfer:
- Gunite-primary builders: Run their own concrete + rebar + plaster crews. Higher fixed-cost operation. Marketing positions on "fully custom design."
- Fiberglass-primary builders: Partner with one or two manufacturers (Latham, San Juan, Trilogy, Imagine). Focus on excavation + plumbing + decking crews. Marketing positions on "fast install + clean swim experience."
Match the right pool method to your customer's yard.
Free account, free rendering, $1 per mailed pool quote. Aerial renders show the pool shape before excavation.
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