Site determines pool type, shape

Press, 18 November 1981, Page 29

Site determines pool type, shape

Site selection is the most crucial factor for a private swimming pool. The site will influence the type of pool selected and also its shape. A sunny area is needed. The pool should not be shaded by overhanging trees, because falling leaves will mean constant maintenance. Shelter from the wind is best provided by screens, fencing or a shelter shed. The position of existing water lines and drains must be established and taken into consideration. The plans and specifications of any pool must meet the requirements of the local authority. This should show the size and location of the pool, types of construction, filtering and drainage details. . . The main types of materials used in construction are concrete, pre-engin-eered vinyl lined, fibreglass and timber. The timber pool is a relatively new addition to the local market. These pools are made of treated timber and have a heavy-duty vinyl liner. An advantage of these pools is that they do not have to be painted or tiled, and the timber blends naturally with the garden. Concrete pools are made of steel reinforced concrete. These are ideal when the site has specific design problems because they can be built to meet them. Above-ground, retaining walls are not necessary because of the method of construction and the strength of the reinforced concrete. There are four methods of using concrete: concrete blocks, concrete spun in a mould (similar to piping), boxing, with concrete poured around the box, and sprayed concrete used in free-form design. The sprayed concrete although a more expensive

method for construction of a swimming pool, provides plenty of scope for design, depth and location. A fibreglass pool uses a combination of three materials. The first is a polyester resin, which is then impregnated with layers of glass fibre, called the laminate. This forms the major structural shell. The final layer is the gelcoat, a thin layer of resin covering the exposed surface of the laminate. These materials are formed into the shape of the pool and then cured. The curing ensures a smooth, hard-wearing surface which is easy to clean. A hydrostatic relief valve

must be installed in the floor of the pool to prevent any build-up of rainwater underneath. Vinyl lined pools are easily and quickly installed. A blue vinyl liner is almost always used in this type of pool and will last for many years if properly installed. Initial cost is cheaper, maintenance is minimal, and the vinyl lined pool can be drained and packed to take with you should you shift. The liner requires no painting and, because of its smooth surface, is easy to clean. The. liner acts as a waterproof membrane with the ground beneath the liner designed to take the water pressure.