Swimming Pool Construction
Aboveground and On-Ground Pools
Aboveground pools range from the simplest circular model, 6 feet (1.8 meters) in diameter, with a uniform depth throughout, to more elaborate pools with an around-the-edge deck and either a sloping bottom or a bottom with a sudden drop at one end to form a "hopper".
The on-ground pool is a variation of the aboveground pool but requires an excavation at one end or in the center for a deep hopper. This allows the pool to be deepened to a maximum depth of 8 to 10 feet for diving. Portability and ease of assembly are two features of aboveground pools. These models can be assembled in a day or less, and when winter arrives they can be easily packed or stored for the season.
Typical aboveground pools are constructed of wood, steel, aluminum, Dr fiber glass. A vinyl liner about (20 mm) thick is usually placed inside the pool to retain the water and protect the pool walls. Large pools are usually reinforced with trusses that support the weight of the water on the walls. Decking, if present, ranges from a top rim just wide enough for sitting to a fully fenced-in area wide enough for sun bathing or patio furniture. For most purposes, the pool should provide at least 36 square feet (3.3 sq meters) of water for each swimmer and 100 square feet (9.3 sq meters) of 8-foot (2.4-meters) deep water for each diver.
The in-ground pool, built of concrete, steel, aluminum, or fiber glass, is nearly always installed by professional pool contractors.
The first and most important step in the installation of an in-ground pool is the excavation. Pool strength and shape depend mainly on the excavation. The most popular in-ground pool shapes are circles, rectangles, teardrops, kidney forms, and free forms.
Poured concrete was previously used extensively in in-ground pool construction but has been replaced to a large extent by Gunite concrete. Gunite is a dry mixture of cement and sand that is mixed with water and forced by a compressor through the nozzle of a hose. Gunite construction eliminates the expense and labor involved in forming the walls and in putting in and removing the wooden forms needed for poured concrete construction. The pool is excavated by machine, and then steel reinforcing rods are placed along the sides and bottom to resist pressure. The Gunite mix is then hosed over and under the steel reinforcing rods. When applied at an even consistency, the Gunite forms a one-piece shell with no weak or thin spots where cracks may form. The concrete is given a week to harden, and the surface is plastered or painted,
Metal pools have a much shorter installation time, but the cost is a little higher. Even though these pools are constructed. to hold water, most of them have a vinyl-lined interior similar to the aboveground pool to protect the pool shell from the reaction to chemicals and water.
These pools are usually constructed in straight or curved panels at the plant and arrive at the pool site ready to be bolted or welded together and dropped into the excavation. This method cuts the on-site construction time in half.
One-piece fiber glass pools are molded at the plant and delivered to the site ready to drop into the excavation. Sectioned fiber glass pools consist of panels, molded together at the pool site. The base of the wall is anchored in a concrete slab, and the sections are bolted and fiberglassed together. Standard fittings and a vinyl coping are installed. The final touch involves the pouring of a deck.
Filters and Pumps
The recirculating system of filter and pump is the most important pool accessory. By filtering and serving as a mixing site for added chemicals, the recirculating system makes it possible for the same water to be utilized over a long period of time. With a good system, one filling with fresh water should suffice for the complete season, with only small amounts of water added to make up for evaporation.
A skimmer can also be a timesaving addition to any pool. It is attached to the filter line to direct the top few inches of the water surface to the filter. The skimmer cleans off foreign matter that tends to float on the pool surface and consequently helps remove it from the pool before it sinks to the bottom where it may be missed or harder to reach.
Heating and Enclosing
Heating a pool is not a necessity from an operational standpoint, but it can extend the pool season by one or more months depending on the climate. The swimming season may be extended to a year-round basis by the installation of a pool enclosure. These vary from small inflatable models to large glass-enclosed types with sliding panels.
All pools need regular maintenance to remain in sanitary condition. The most important task involves keeping the water chlorinated to eliminate bacteria and algae that endanger the swimmers' health or make swimming unpleasant. A chlorine test kit is essential. Testing involves filling a small tube with water and adding a few drops of test solution. The treated water is then compared with color standards to determine the chlorine content. The water should be tested on a daily basis and chlorine added if required, to bring the chlorine content to within the proper range.
The pool should also receive a thorough vacuuming at least once a week to keep it clean and attractive and to remove debris that has settled at the bottom of the pool. If the pool is equipped with a surface skimmer, which is in constant use, vacuuming can be a simple procedure involving 10 or 15 minutes a week.
Both the vacuum and the skimmer pull foreign matter from the pool and direct the water through the filter. Vacuums usually include a cloth bag in which heavier particles are trapped to make the filter load lighter.
Also available are automatic pool cleaning systems that partially eliminate weekly cleaning. These systems force clean water from the filter through a floating head that churns up debris to be filtered out, while heavier particles are forced out through the main drain. During the off-season, permanent pools may be cleaned only every few weeks.