Section 2 – Types of Pools and Fountains
2.1 In-Ground
There are three types of in-ground pool constructions: fiberglass, vinyl, and concrete. Each type of in-ground pool needs a pump, filter, drains, returns, plastic piping, and a chemical feeder.
Fiberglass pools are noted for their relatively quick installation, non-abrasive finish that resists staining, and inert composition that inhibits algae formation. Fiberglass pools are manufactured in a variety of shapes and sizes and are shipped to the installation site in one piece. Once the pool is in place and leveled, heating, filtration, and other systems can be installed and set up. The installation crew then backfills the site and fills the pool with water. Fiberglass pools are rarely tiled completely, but many do have a decorative band installed around the waterline of the pool. The use of a 100% solids epoxy setting material (e.g. LATAPOXY® 300 Adhesive) is required for installation of tile to fiberglass.
Vinyl-lined pools, known for their smooth, stain-resistant surface, are a very popular choice for in-ground pools. Design options are typically limited, but they are less expensive than fiberglass or concrete pools. Depending on the soil composition, once the excavation is complete, a wall system is constructed of wood, poured concrete, steel, or polymer. Bottom material might be of packed sand that is free of stones or poured concrete. Once the vinyl liner is installed and the heating, filtration and other systems are set up, the site is backfilled and the pool is filled. Liners usually have to be replaced about every 10 years, depending on usage and geographic location. Tile should not be installed in a vinyl lined pool.
A concrete pool is, by far, the most popular choice for in-ground pools. Concrete pools can take several weeks to construct and set up, but the design possibilities are endless. There are basically 4 choices when choosing the type of concrete pool construction.
Concrete Block – In concrete block pool construction, a floor foundation is poured and a concrete block wall is constructed to the desired shape of the pool. After the filtration attachments are inserted into the structure the walls are typically reinforced with deformed steel bars and all internal cavities of the block are solid filled. Once the shell is completed the pool can be tiled or finished in any number of ways.1
Poured Concrete – In poured concrete construction, a form is typically created using plywood in the desired shape of the pool. The pool floor is poured first and the walls are constructed on top of the floor, around a steel reinforcing web. The cavities in the forms are filled with a high density concrete specifically designed and mixed for pool construction. A vibrating tool is utilized to fill any cavities and honeycomb voids and to make sure that the steel reinforcing is completely encapsulated. Once the forms are removed and the concrete is allowed to cure for a specified length of time, the pool can be tiled or finished using another method.2
Gunite – In Gunite pool construction, a wood form is created and installed inside the excavated pool hole. The shape and size of the wood form is made larger than the desired finished pool by the thickness of the walls. Steel reinforcement is constructed and installed at pre-determined distances based on local construction code requirements. This steel reinforcement is suspended away from the wood form which helps keep the reinforcement centered within the wall and away from the bottom of the drainage material layer underneath the pool. The Gunite concrete is then pneumatically sprayed onto and around the steel reinforcement and wood form to the desired thickness of the pool walls. The Gunite mix (cement and pool aggregate mix) is delivered down a hose as a dry mix under pressure and blended at the spray head with potable water. The Gunite operator is responsible for maintaining the proper water to powder ratio to get the maximum strength from the concrete. Once sprayed in place the interior of the pool is troweled and formed to straighten the interior walls. Once cured, a Gunite pool can be tiled or finished using another method.3
Shot-Crete – In Shot-crete pool construction, the preparation of the form and steel reinforcement is similar to Gunite. The main difference is the way that the concrete is delivered and applied. Shot-crete arrives at the site as a ready-mix concrete from the batching plant and is delivered in a cement truck. Quality of the concrete is determined at the batching plant during mixing and the spray operator has no control over the final quality of the concrete. Once cured a shot-crete pool can be tiled or finished using another method.4
Finished cost of a concrete pool will vary depending on region, landscaping, construction type, and design. A concrete pool requires an interior surface finish which, with the various colors and textures to choose from, is limited only by your imagination. Concrete finishes typically need resurfacing about every 10–15 years. However, tile installations in a properly maintained swimming pool or fountain can
last a lifetime.
2.2 Above Ground
Above ground pools function much the same way as an in ground pool but at a fraction of the cost.
There are two types of above ground swimming pools – pools with hard sides and pools with soft sides.
Hard sided above ground pools are normally round or oval and are available in a variety of sizes and depths. They have a sheet metal frame which has a one piece flexible metal wall fixed to it with a sheet metal rail attached to the top for stabilization. A vinyl liner is then inserted and attached to the top rail to contain the water. Although cheaper than a soft side above ground pool, a metal sided swimming pool requires more elaborate ground preparation and is considerably more difficult to assemble.
Soft sided above ground pools are normally available in both round and the more popular rectangle shape. Although they have been around for some time, soft sided above ground swimming pools have become increasingly popular over the last 10 years. Like their metal wall predecessor, they are also available in a variety of sizes and depths. In fact, due to their strength and durability, they are quite often custom built in extremely large sizes for use in commercial applications. Soft sided pools can be placed on any surface, grass, dirt, concrete, even sand or gravel, and will normally tolerate up to 3" (75 mm) out of level. The pool liner material is similar to that used for bullet proof vests and therefore is extremely durable and puncture resistant. The average family can normally assemble a soft side pool in a relatively short amount of time and can move it as often as needed.
Both types of above ground pools require a filter and an electric pump to circulate the water and a ladder to get in and out of the pool. Other desirable accessories may include an
automatic pool cleaner, an automatic chlorinator, a pool heater, lighting or a swimming pool slide. Due to the types of construction materials and the flexibility of the walls, tile is never used in above ground pools.
2.3 Suspended Pools
Pools and fountains do not necessarily have to be located in or on solid earth. In fact, many pools and fountains are located above ground level, either within a structure or on top of a structure, and are supported by the structure itself. This type of pool or fountain must be designed with critical factors in mind; the pool cannot leak and the structure must be able to support the total weight of the pool, the water and occupants within the pool. If the pool is located indoors then the structure must also be designed and constructed to handle the excessive humidity created by the pool, and the chemicals used to sanitize and maintain the pool. In most cases, the pool mechanical room is located in a room below the pool level to better utilize gravity in the circulation of water.
Tile is a common feature inside of a suspended pool or fountain, and can be installed within the entire pool and deck area or just in a band around the waterline.
Figure 2.1 – Suspended pool on an upper floor of the Swissôtel in Chicago, IL.
2.4 Spa / Therapeutic
The use of spas, hot tubs and therapeutic pools has been consistently rising for several decades as new and less expensive manufacturing techniques have been established. Many of these installations contain tile. Some of the differences between a pool and a spa, hot tub or therapeutic pool are temperature (these vessels typically contain hot water or water that is routinely heated), and size (many of these vessels are designed to hold a small number of occupants). The construction of spas, hot tubs and therapeutic pools commonly consist of stainless steel or fiberglass. Water treatments are similar to what is used in a swimming pool (Bromine is the preferred treatment for hot water) but the increased temperature can have an impact on the effectiveness of these treatments and how they react with fittings, tile or stone, plumbing, etc...
We will cover the methods of swimming pool and fountain construction in greater detail in Section 3 “Types of Pool and Fountain Construction”.
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