Jagvir Goyal
There were times when a swimming pool used to exist either in a five star hotel or in the sports training institutes. Times have changed and now, swimming pools are developed in all the clubs of standard, society complexes, farm resorts, big bungalows and even on terraces. These add to the style and status of the owner. However, simple construction of a swimming pool in a complex or house doesn’t close the chapter. Rather a full job of its maintenance lands in the hands of the owner and he has to draw a clear cut program for its periodic maintenance.
The culture of having a personal swimming pool within the boundary of a large bungalow, a farmhouse or a villa is fast catching up in metros. Somehow the blue waters with umbrellas and lounging chairs put nearby attract people like a magnet. Many builders are today providing swimming pools in penthouses or at terraces for apartments.
Area Requirements: A club, colony or hotel can always have a swimming pool of desired shape and size. Barring a few exceptions, within a residential unit, area constraints are always there. However private pools are always of smaller size than public pools. The smallest size of a pool can be as less as 150 square feet. However it may give the feeling of a large tub or a wading pool. Normal pool size for private use is 16 feet X 32 feet.
Depth Requirements: Depth of a swimming pool depends upon the fact whether it is to be used for swimming only or for diving also. In residential areas, diving in pools is avoided as it requires too much depth in diving portion of pool so that the head doesn’t strike the floor on diving. Depth of a swimming pool may be kept uniform or variable. A pool with uniform depth shall have a flat bottom. A pool with variable depth has a combination of two different depths by combining a flat bottom for some length with a sloping one for balance length. A flat bottom pool is good for freshers, a variable depth pool for a family and a deep sloping one for sports persons. A swimming pool, in general has a depth between 0.80 metre to 1.80 metres.
Level: Level of the pool means whether it is to be constructed on the ground or on a floor of the building. These days, swimming pools are provided by builders on various floors in luxury apartments. It is a costly proposition and requires immense care and safety in design against structural failures and leakages. A pool at any floor of the building will alter the structural design of the building as the weight of the pool and the water contained in it will have to be taken into account.
Shape: A pool may be of any shape but a rectangular or square pool is most preferred as there is no hindrance in straight swimming. In an oval or dumbbell shaped pool, one has to take care that he doesn’t strike the wall. The swimming distance also gets reduced and the number of users is restricted. Therefore, prefer a rectangular shape for the swimming pool.
The Structure: Once the parameters are decided, structural design of the pool should be evolved. See that the pool has a RCC base slab with RCC walls all round, their joints with the base slab made water proof by inserting PVC water bars or stoppers in them. This has to be done at the time of concreting of slab and walls. Here, proper insertion of water bar or stopper, equally in the slab and wall is very important. Generally this bar is not given due attention and is found inserted in a wavy manner. This results in leakages at the junctions. To avoid leakage and maintenance problems, a swimming pool must be made hydraulically tight. Add water proofing compound to concrete. Thickness of bottom slab can be kept between 9 to 12 inches. The walls may have varying thickness, thicker at bottom and thin at top end. Keep wall thickness as 9 inch at top and around 14 inch at bottom. Always provide steel on both faces of walls and bottom slab. 8 mm dia and 10 mm dia steel if provided at suitable spacing can make the structure safe. Use M20 mix for concrete.
The Tiles: Choose glazed or mat finish tiles for the pool. Glass mosaic tiles look still better. The deck flooring can be in terracotta tiles or a mix of red sand stone and kota stone.
Filtration Plant: Filtration plant is the most important attachment to a swimming pool to keep it hygienic and workable. Its capacity depends upon two things:
1. Volume of water in the pool
2. Turn over period.
Turn over period is the time period in which in which the total pool volume shall pass through the filtration system once. Lesser is the turnover period, more clean and clear is the pool water. However too less turn over period unnecessarily increases the load on the filtration units. Therefore, choose turn over period carefully by estimating the number of users and the hours in which the water is likely to get dirty. Peak hours of summer days should be considered. For a pool having a water volume of 1 lac litres, a turn over period of 5 hours is normally sufficient. Residential pools may have turn over periods of 8 to 10 hours.
The filtration plant consists of circulating pump and filters. The circulating pump turns the pool water through the filters to clean it. The capacity of Circulating pump can be worked out by dividing the volume of water with turn over period. A pool having 1 lac litres of water and turn over period of 5 hours should have circulating pumps of 20000 litres per hour capacity. Prefer pumps of smaller capacity but more in number as the circulation system will continue to work if some pump goes out of order.
The filters are called pressure sand filters. These may be of stainless steel or anti-corrosive fibre glass or polyester resin filters. Their filtration rate is kept low. Slower is the filtration rate, more effective is the filtration. However in private home pools, medium or high filtration rate is permissible. A rate of 6 litres per sq. inch per hour can be said as a low rate while a rate of 20 litres per sq. inch per hour is a high rate of filtration.
Choose a filtration plant that is capable of handling any type of water pollution such as dust, leaves, chemical wastes, bacteria, spores, pollen etc. It should also be able to handle the pollution caused by swimmers through sweat, sun tan oils, urine, bacteria and viruses. The filtration plant should have proper system of valves to handle backwashing of filters.
Backwashing of all filters should always be done at least once a week. When the pressure gauges start showing extra pressure of 0.2 kg/sq.cm that means extra clogging of filters has occurred and these should be backwashed.
The Dosing: Add a dosing pump system to your pool maintenance kit. There should be separate dosing pumps for chlorine and Soda Ash. These should add chlorine and soda ash to water to disinfect it and to correct its pH value.
Piping & Valves: Take special care of the pipes, valves and gratings for the pool. These are required for inflow of clean water and outflow of used water. Keep the main drain in stainless steel. See that the bottom inlets and grating Supports are anti corrosive, preferably made in plastic. The other piping and valves may be of unplasticized PVC and able to handle the required pressure. Provide the pool with deck overflow channels. The drainage pipes connecting the overflow channels to the balance tank should have 25% extra capacity.
The Lighting: Under water lights add to the beauty of the swimming pool, make it usable during night and should always be provided. Prefer to have extra flat lights and that too without requirement of niche so that these make no hindrance in swimming. Color choice is yours.
The Construction: It is always better to get a swimming pool constructed on turnkey basis. You need to tell the capacity, size, shape and depth of the pool required, finalize the amount to be paid and rest can be left to them. However, you can always prescribe the makes of equipment, type and color of tiles, color and pattern of lighting. A maintenance guarantee should be secured from the turn key contractor. Chinese equipment should be avoided. Prefer the equipment supplied by a FINA approved company. FINA is the international body that approves the equipment suppliers for Olympics swimming events. These companies can’t put their own reputation at stake and provide standard equipment at reasonable rates.
Portability: These days, portable pre-fab swimming pools have also become available. These can be of any shape or size, can be installed indoor or outdoors, above or below ground level. A 20 feet X 12 feet pool with depth of 4 to 5 feet costs around Rs. 5 lacs. These are equipped with filtration unit, chlorine dispenser, purifier, special liners and other accessories. Choose one if you want to avoid all the construction activity.
The last word: It is better not to have a swimming pool than first constructing it and then not maintaining it. An ill maintained swimming pool invites unhygienic conditions around its location, spreads disease among the users and ultimately stops functioning, making waste of all the expenditure done on its construction. Draw a pool and equipment maintenance chart and religiously get the chores done. We may discuss this when we dawn upon maintenance problems.
