Resources
Pool Terminology Glossary
Plain-English definitions for every term you'll hear during a pool build. No jargon, no guesswork.
Construction and Structure
- Gunite
- A dry-mix form of shotcrete where cement powder and aggregate are premixed, then water is added at the nozzle just before spraying. Gunite pools are built on-site by spraying the concrete mixture over a steel rebar cage, forming the shell of the pool.
- Shotcrete
- Concrete pneumatically projected (sprayed) at high velocity onto a surface. Gunite is a specific type of shotcrete. Both methods produce a strong, durable concrete shell and are used interchangeably in pool construction — your builder's crew and equipment determine which method is used.
- Rebar Cage
- A grid of steel reinforcing bar (rebar) tied together and placed in the excavated pool shape before concrete is applied. The rebar cage gives a gunite or shotcrete pool its structural strength and prevents cracking over time.
- Bond Beam
- The top structural edge of a gunite pool's concrete shell, typically the top 12 inches or so. The bond beam anchors the coping, supports tile work, and ties the pool shell to the surrounding deck. A well-built bond beam is critical for long-term structural integrity.
- Fiberglass Pool
- A pool shell manufactured off-site from fiberglass-reinforced plastic, then trucked to your yard and dropped into the excavated hole. Fiberglass pools have a smooth, non-porous gel coat surface that resists algae, and the shell is flexible enough to handle Virginia's freeze-thaw soil movement better than bare concrete.
Surfaces and Finishes
- Plaster
- The interior finish applied to a gunite pool shell after construction. Standard white plaster (marcite) is a mix of white Portland cement and marble dust. It creates the smooth, watertight surface you actually touch and swim against. Plaster typically lasts 10-15 years before replastering.
- Pebble Finish
- A premium interior finish that blends small natural pebbles or quartz aggregates into the plaster mix. Pebble finishes (brands like PebbleTec) are more durable than standard plaster, last 20+ years, and give the pool water a natural, jewel-toned look.
- Coping
- The cap or edging material installed along the top perimeter of a pool shell, sitting on the bond beam. Coping creates a finished edge between the pool water and the deck, provides a safe non-slip grip for swimmers, and protects the pool structure from water runoff. Common materials include travertine, bullnose brick, and cantilevered concrete.
- Waterline Tile
- A band of tile installed around the perimeter of the pool at the waterline. Waterline tile protects the coping and plaster from the oils, sunscreens, and minerals that concentrate right at the water's surface. It's also one of the most visible design elements in a finished pool.
Pool Features and Add-Ons
- Tanning Ledge (Baja Shelf)
- A large, shallow platform built into the pool, typically 6-9 inches deep. You place a lounge chair on it and sit in the water without fully submerging. Tanning ledges are one of the most requested features in new pool builds and work equally well as a wading area for young children.
- Spillover Spa
- A hot tub or spa attached to the pool that sits elevated enough so water spills over the edge into the main pool. Spillover spas share the pool's plumbing and equipment but can be heated independently, giving you both a heated spa and a cooler swim pool.
- Vanishing Edge (Infinity Edge)
- A design where one or more edges of the pool have no visible wall — water flows over the edge into a catch basin below, creating the illusion that the pool merges with the horizon or landscape beyond. Vanishing edge pools require a second pump system and a catch basin, and they work best on lots with a grade change or a view.
- Sheer Descent
- A water feature that produces a thin, glass-like sheet of water falling from a raised ledge into the pool. Sheer descents add visual elegance and the sound of moving water. They're controlled by a valve and can be turned on or off as desired.
- Bubbler
- A small water jet installed in shallow areas like tanning ledges or beach entries that shoots a gentle arc or column of water upward. Bubblers are popular in family pools because young children enjoy playing in them while adults relax nearby.
- Automatic Cover
- A motorized pool cover that rolls across the surface of the pool at the push of a button. Automatic covers reduce evaporation, keep debris out, retain heat, and meet most local safety barrier requirements for pool enclosures in Virginia.
Plumbing and Equipment
- Skimmer
- An inlet built into the pool wall at the waterline that draws surface water (and floating debris like leaves) into the filtration system. Most pools have two or more skimmers. Keeping skimmer baskets clear is one of the most important weekly maintenance tasks.
- Main Drain
- A drain at the bottom of the pool that provides suction to the pump and helps circulate water from the deep end. Modern pools use dual main drains with anti-entrapment covers to meet VGB Act safety requirements. The main drain works alongside skimmers to ensure full water circulation.
- Returns (Return Jets)
- The fittings built into the pool walls that push filtered, treated water back into the pool. Aiming returns correctly creates a circulation pattern that moves debris toward the skimmers and helps distribute chemicals evenly throughout the water.
- Variable-Speed Pump
- A pool pump that can run at multiple speeds rather than a single fixed speed. Running a variable-speed pump at lower speeds for longer periods moves the same volume of water while using significantly less electricity — often 50-80% less than a single-speed pump. Virginia and most states now require variable-speed pumps on new pools.
- Heat Pump
- A pool heating system that extracts heat from ambient air and transfers it to the pool water, similar to how a household heat pump works. Heat pumps are far more efficient than gas heaters in moderate climates like Northern Virginia, where spring and fall temperatures stay above 50°F. They cost more upfront but dramatically less per month to operate.
Water Chemistry
- Salt Chlorination (Salt Water Pool)
- A system that generates chlorine on-site by passing pool water over a salt cell, which uses electrolysis to convert dissolved salt (sodium chloride) into chlorine. Salt water pools still use chlorine — they just produce it continuously from the salt instead of requiring you to add chlorine manually. The water feels softer and less irritating to eyes and skin.
- Cyanuric Acid (Stabilizer)
- A chemical that protects chlorine from being broken down by UV sunlight. Without stabilizer, chlorine in an outdoor pool degrades within hours of direct sun exposure. Too little stabilizer and chlorine burns off before it can sanitize; too much and chlorine becomes ineffective even at normal levels.
- Total Alkalinity
- A measure of the water's ability to resist changes in pH. Keeping total alkalinity in the correct range (typically 80-120 ppm) prevents pH from swinging rapidly up or down, which protects pool surfaces, equipment, and swimmer comfort.
Deck and Surrounds
- Pool Deck
- The hard surface area surrounding a pool. Common materials in the Fredericksburg area include brushed concrete, exposed aggregate, pavers (travertine, bluestone, or brick), and stamped concrete. Deck material affects heat absorption, slip resistance, and maintenance requirements.
- Cantilever Deck
- A poured concrete deck that overhangs the pool coping slightly, creating a smooth, seamless edge with no visible gap between the deck and the pool. Cantilever decks eliminate the joint where debris and water accumulate in traditional coping installations.
Know the Terms. Now Build the Pool.
K&D builds custom gunite and fiberglass pools in Fredericksburg, Spotsylvania, Stafford, and Northern Virginia.