Everything you always wanted to know about pools

Before you invest in your pool or spa, you need to know exactly what your contractor is talking about. The more you know, the more able you are to get exactly the result you want from your renovated pool. So here are some important terms to understand:

Auxiliary area: A dressing, locker, shower, toilet area, or building space intended to be used by bathers.

Backwash: The process of thoroughly cleansing the filter media and/or elements, and the contents of the
filter vessel.

Bottom suction outlet: See main drain.

Cantilever Deck: Monolithic poured concrete that overhangs the edge of the pool waterline
(See Vertical Mastic).

Chlorine Generator: Apparatus by which salt is transformed into chlorine by means of an electrical charge through a cell.

Clear pool water: Pool water that is free from cloudiness and is transparent.

Clean pool water: Pool water that is free of dirt, oil, scum, algae, floating materials, or other visible organic and inorganic materials that would sully the water.

Coping: The cap material installed on top of the pool edge that finishes flush with the surrounding deck.

Deck: An area surrounding a pool Drain: A fitting or fixture, usually at or near the bottom of a pool, through which water leaves the pool--normally to the recirculation pump.

Effective particle size: The theoretical size of sieve (in millimeters) that will pass 10 percent by weight of the sand in a high-rate sand filter.

Equipment area: an area used for pool recirculation and purification equipment and related piping.

Expansion joint: Non-corrosive material used to separate two structures and allow for movement.

Elevation: Height at which the top of the pool is set in relation to other structures. The elevation of the pool usually denotes the top of the finished coping material.

Epoxy Injection: Process of installing non-structural epoxy at high pressure to seal cracks in a
gunite structure.

Gunite: One sided dry mix application of pneumatically placed concrete used to create the structure of a
pool or spa. Also known as shotcrete.

Inlet: A fitting or fixture through which circulation water enters the pool. Ladder: A series of horizontal
treads or rungs, either connected by vertical rail members or independently fastened to an adjacent
vertical pool wall.

Main drain: A fitting or fixture at the deepest portion of the pool, through which circulation water is removed from the pool for the purpose of recirculation or draining.

Mastic: a soft, pliant, joint material that forms a seal between the coping and the concrete deck.

Medical pool: A special-purpose pool used by a state-recognized medical institution engaged in the healing arts under the direct supervision of licensed medical personnel.

Overflow system: Perimeter overflow gutters, surface skimmers, surge or collector tanks, other
surface water collection system components, and their interconnecting piping used to remove excess
water from pools.

Overlay: Process of installing rock, tile, or thin concrete over and existing concrete deck.

Plaster Preparation: The means of preparing a pool or spa for replaster by means of sandblast
or hydro-blast.

Pool volume: The amount of water, expressed in gallons, that a pool holds when filled.

Recessed steps: A riser/tread or series of risers, extending down from the deck and terminating at the pool well that creates a stairwell.

Recessed treads: A series of vertically spaced cavities in the pool wall that creates tread areas for
step holes.

Recirculation system: The interconnected system traversed by recirculated pool water. For example, from the pool through the collector or surge tank, recirculation pump, filters, chemical treatment, and heater, and back to the pool.

Shallow pool: A pool with a maximum depth of less than six feet.

Skimmer: A fixture mounted in the side wall of a pool, through which surface water is removed from the pool for the purpose of recirculation.

Strip: Removing the existing plaster from the pool exposing the original gunite structure underneath.

Surge tank: Large vessel for capturing overflow water in competition pools equipped with a gutter recirculation system.

Trim tile: 1” or 2” non-skid tiles installed on each step or bench to mark the edge of the vertical riser.

Turnover time: The period of time in hours, required to circulate a volume of water equal to the
pool capacity.

Vertical Mastic: Mastic installed between the waterline tile and a cantilevered deck.

Waterline: Either the midpoint of the operating range of the skimmer(s), or the top edge of the overflow rim.

Water treatment: The process of conditioning and disinfecting pool water by filtration and the addition
of chemicals.