Reference
Pool glossary.
41 terms - construction, finishes, equipment, water chemistry, design, and permitting - defined in plain English by a working Carolina pool builder.
Construction
- Gunite
- A dry-mix concrete sprayed pneumatically over a steel rebar cage to form the structural shell of a custom inground pool. Gunite is hydrated at the nozzle and sets into a high-PSI shell that lasts 50+ years. The dominant build method for custom concrete pools in North Carolina.
- Shotcrete
- A wet-mix concrete sprayed over the rebar cage to form the structural shell. Shotcrete arrives pre-mixed (vs. gunite, which is mixed at the nozzle) and is generally considered more consistent. Both terms are often used interchangeably in the field.
- Rebar Cage
- The grid of steel reinforcing bars tied together inside the excavated pool hole, before shotcrete is applied. The rebar cage gives the concrete shell its tensile strength and resistance to soil movement.
- Fiberglass Shell
- A pre-manufactured, one-piece pool body delivered by truck and craned into the prepared excavation. Fiberglass shells install in 8–12 weeks and carry 25–30 year structural warranties from the manufacturer.
- Excavation
- The dig phase of pool construction. In Lake Norman, NC, most lots have red clay over weathered piedmont rock; Rock Water engineers footings to soil report rather than to a generic template.
- Shell
- The structural body of the pool - gunite/shotcrete for concrete pools, or one-piece fiberglass. The shell is everything below the tile band and coping.
Finishes & Materials
- StoneScapes
- A premium aggregate interior finish for concrete pools made of small natural pebbles in a polymer-modified cement matrix. StoneScapes lasts 20+ years, hides debris, and comes in deep blues, greens, and earth tones. The most popular interior finish on Rock Water Lake Norman builds.
- PebbleSheen
- A finer-grained variant of StoneScapes using smaller pebbles for a smoother feel underfoot. Same 20+ year lifespan and color depth, with a more refined surface texture.
- Plaster
- A traditional white cement-and-marble-dust interior finish for concrete pools. Lower cost than aggregate finishes but typically needs replacement every 8–15 years vs. 20+ for StoneScapes.
- Polished Quartz
- A high-end aggregate interior finish using crushed quartz instead of pebbles. Smoother than StoneScapes, with a slight sparkle in sunlight. 20+ year lifespan.
- Travertine
- A natural stone widely used for pool coping and decking in NC and SC. Travertine stays cool underfoot, drains quickly, and weathers attractively. Saltwater-safe when properly sealed.
- Bluestone
- A dense natural stone (typically Pennsylvania bluestone) used for premium pool coping and decks. Hard, slip-resistant, and saltwater-compatible. More expensive than travertine.
- Coping
- The cap stone or material installed around the top edge of the pool shell, between the waterline tile and the deck. Coping protects the shell, defines the pool's edge, and provides a comfortable hand-hold.
- Waterline Tile
- The decorative tile band installed at the water level of a concrete pool. Glass, porcelain, or natural stone. Waterline tile resists staining and scale buildup at the waterline more effectively than the interior finish would.
Equipment
- Salt Cell
- An electrolytic chlorine generator that produces chlorine on demand from dissolved salt in the pool water. Salt cells eliminate the need to handle chlorine tabs or liquid. Cells last 3–7 years and cost $700–$1,400 to replace.
- Variable-Speed Pump
- A pool pump that runs at adjustable RPM rather than a single fixed speed. Variable-speed pumps cut electrical cost by 50–80% vs. single-speed pumps and run quieter. Required by code in many NC and SC jurisdictions on new pool installs.
- Pool Automation
- A controller (Pentair IntelliCenter, Hayward OmniLogic) that manages pumps, lights, heater, salt cell, and water features from a phone app. Modern automation supports schedules, away-mode, and freeze protection.
- Heat Pump
- A pool heater that pulls warmth from outside air to heat pool water - far more efficient than gas heaters when ambient temperatures stay above 50°F. Common choice for shoulder-season heating in the Carolinas.
- Gas Heater
- A natural gas or propane pool heater that heats water rapidly regardless of ambient temperature. Used when fast warm-up matters or for spas. Costs more to run than a heat pump but heats faster.
- Pool Filter
- The system that removes debris from circulating water. Three types: cartridge (most common, easy to clean), DE (diatomaceous earth, finest filtration), and sand (lowest cost, easiest backwash).
- Equipment Pad
- The concrete pad holding the pump, filter, heater, automation box, and salt cell - typically at least 6 by 10 feet. Suction-line physics caps placement at roughly 50–75 feet from the pool; most residential pads land 10–40 feet away for the best balance of efficiency and visual separation. Needs 2–3 feet of clearance on all sides and ventilation - equipment should be screened, never fully enclosed.
Water Chemistry
- Free Chlorine
- The active sanitizing chlorine in the water (vs. combined chlorine, which is already used up). Target range: 1–3 ppm in residential pools. Below 1 ppm, algae and bacteria can establish.
- pH
- A measure of how acidic or basic the pool water is. Target range: 7.4–7.6. Low pH corrodes equipment and irritates eyes; high pH causes scale and reduces chlorine effectiveness.
- Total Alkalinity
- A measure of the water's resistance to pH change. Target range: 80–120 ppm. Stable alkalinity makes pH easier to manage and protects the interior finish.
- Calcium Hardness
- The amount of dissolved calcium in the water. Target range: 200–400 ppm. Low calcium pulls minerals from plaster and stone; high calcium causes scale on equipment.
- Stabilizer (Cyanuric Acid)
- A chemical that protects chlorine from UV breakdown by sunlight. Required outdoors. Target range: 30–50 ppm. Excess stabilizer (above 100 ppm) reduces chlorine effectiveness.
Design Features
- Vanishing Edge
- A pool design where one edge of the pool slopes away into a hidden catch basin, creating the illusion that the water extends to the horizon. Also called an infinity edge. Adds $30,000–$60,000 over a comparable pool without one. Common on Lake Norman lake-front and view lots.
- Tanning Ledge
- A shallow shelf (typically 6–12 inches deep) inside the pool, designed for in-water lounging on submerged chairs or sunbathing. Standard on most modern Carolina builds. Often paired with bubbler jets or umbrella sleeves.
- Sun Shelf
- Another name for a tanning ledge - a shallow in-pool shelf designed for in-water lounging.
- Spillover Spa
- An integrated spa at one end of the pool that overflows back into the main pool body. Provides hot-tub function while moving water and circulating chemistry. Common in Lake Norman builds.
- Raised Spa
- A spa built above pool deck level, typically with a sheer-descent or weir spillway returning to the pool. Adds $18,000–$32,000 over a flush spillover spa.
- Sheer Descent
- A water feature that delivers a thin, smooth sheet of water from a wall or raised spa into the pool. Visual centerpiece on many premium Lake Norman builds.
- Fire Bowl
- A decorative gas-fired bowl mounted on the pool deck or raised spa edge. Typically installed in pairs or sets of four. Adds $14,000–$22,000 for six bowls on automation.
- Beach Entry
- A gradual concrete slope from the pool deck into the water, dropping at roughly 1 inch per foot with no steps. Also called a zero-entry or zero-depth entry. Adds $8,000–$18,000 to a new build, or $12,000–$28,000 combined with a tanning ledge. Needs return jets or bubblers to keep the shallow water circulating - poor circulation turns it into an algae zone.
- Grotto
- A built-in rock cave or cavern integrated into the pool design, typically 4–6 feet deep with a waterfall entry and interior lighting, built from steel-reinforced gunite during original construction. Budget $20,000–$50,000. Works best on pools with 450+ square feet of water surface; all plumbing, electrical, and audio conduit must be planned in from the start, since retrofitting means breaking into cured gunite.
- Swim-Up Bar
- An in-pool bar with submerged seating, typically 36–40 inches deep - shallower than the main swim zone but deeper than a tanning ledge. A wet ledge bar built into the shell adds $8,000–$15,000; a full freestanding bar structure with utilities runs $20,000–$45,000. Electrical, plumbing, and gas rough-ins must be run during excavation, or trenching later adds $3,000–$8,000.
Process & Permitting
- ARC (Architectural Review Committee)
- The HOA committee that reviews and approves exterior changes - including pool builds - at planned communities. Lake Norman communities with active ARCs include The Peninsula, The Point, The Farms, Bridgeport, and Davidson Landing. Reviews typically take 2–5 weeks.
- Pool Permit
- Every NC and SC inground pool requires a building permit, electrical permit, and often stormwater or land-disturbance permits. Iredell County permits typically issue in 3–5 weeks; Mecklenburg County in 5–8 weeks.
- Soil Report
- An engineering analysis of the soil composition at the pool location. Required by some jurisdictions and used to engineer the structural footings and drainage. Most Lake Norman lots show red clay over weathered piedmont rock.
- Start-Up
- The final phase of pool construction: filling the pool, balancing chemistry, commissioning equipment, and orienting the homeowner. New StoneScapes finishes require 30 days of stabilization service before normal use.
- Pool Fence / Barrier
- North Carolina and South Carolina require a 4-foot barrier around every inground pool. The barrier can be the property fence or a dedicated pool fence; gates must be self-closing and self-latching.
Keep learning
For deeper reads, see our buyer's guides and Carolina-specific pool knowledge. For pricing detail, see concrete vs. fiberglass.
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