swimming pools 4ed philip h perkins 2

swimming pools 4ed philip h perkins 2

Swimming Pools

This edition published in 2000 by E & FN Spon

11 New Fetter Lane, London EC4P 4EE

Simultaneously published in the USA and Canada by Routledge

29 West 35th Street, New York, NY 10001

This edition published in the Taylor & Francis e-Library, 2003.

E & FN Spon is an imprint of the Taylor & Francis Group

First edition 1971

Second edition 1978

Third edition 1988 (Elsevier Applied Science Publishers Ltd)

© 2000 Philip H Perkins

All rights reserved No part of this book may be reprinted or reproduced or utilised in any form

or by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying and recording, or in any information storage or retrieval system, without permission in writing from the publishers.

The publisher makes no representation, express or implied, with regard to the accuracy of the information contained in this book and cannot accept any legal responsibility or liability for any errors or omissions that may be made.

British Library Cataloguing in Publication Data

A catalogue record for this book is available from the British Library

Library of Congress Cataloging in Publication Data

A catalog record for this book has been requested

ISBN 0-203-47788-X Master e-book ISBN

ISBN 0-203-78612-2 (Adobe eReader Format)

ISBN 0-419-23590-6 (Print Edition)

1.2 Basic requirements for all swimming pools

1.3 Pools for private houses, clubs, hotels and schools

1.4 Covered pools for private houses, hotels, clubs and schools1.5 Teaching/learner pools

1.6 Public swimming pools

1.7 Floor gradients

1.8 The drainage of walkways and wet areas

1.9 Hydrotherapy pools

1.10 Pools used for sub-aqua activities

1.11 Facilities for the disabled

1.12 Swimming pools with movable floors

1.13 Wave-making machines

Recommended procedure for getting a pool built: contracts and

dealing with disputes

1.14 Introduction

1.15 Contracts: how to proceed

1.16 Dealing with disputes

3 Factors affecting the durability of reinforced concrete and

cement-based materials used in the construction of swimming pools3.1 Introduction

3.2 Corrosion of steel reinforcement in concrete

3.3 Carbonation of concrete

3.4 Chloride-induced corrosion of reinforcement

3.5 Deterioration of the concrete

3.6 Chemical attack on cement-based mortar

3.7 Swimming pool water and chemicals used in water treatment3.8 Moorland water and the Langelier Index

4.4 Flotation (uplift) of the pool shell

4.5 General comments on design and construction

4.6 Concrete construction in cold weather

4.7 Concrete construction in hot weather

4.8 Plastic cracking

4.9 Thermal contraction cracking

4.10 Swimming pools with floor slabs supported on the ground4.11 Construction of the walls of the pool

4.12 Construction of walkway slabs and floors of wet changingareas

4.13 Curing the concrete floor and walls of the pool

4.14 Construction of suspended pool shells

4.15 Thermal insulation of swimming pool shells

4.16 Under-water lighting and under-water windows

5.10 Construction of the floor

5.11 Construction of the walls

5.12 Pipework

5.13 Under-water lighting

5.14 Curing the concrete and protecting the blockwork

5.15 Testing for watertightness

5.16 Back-filling around the walls

5.23 Finishes to floor and walls

5.24 Testing for watertightness

5.25 Back-filling around the walls

5.26 Thermal insulation

Other methods of construction

5.27 General comments

5.28 Pools constructed with mass (gravity) type walls

5.29 Curing the concrete

5.30 Testing for watertightness

5.31 Pools constructed in very stable ground such as chalk or rock5.32 Pools constructed of precast post-tensioned concrete units5.33 Pool shells of steel

Finishing the pool shell and associated structures

7.1 Cement-sand rendering to insitu concrete walls

7.2 Cement-sand rendering to sprayed concrete walls

7.3 Cement-sand rendering to concrete block walls

7.4 Cement-sand screeds on insitu concrete floors

7.5 Cement-sand screeds on sprayed concrete floors

7.6 Ceramic tiles and mosaic

7.7 Walkways and wet changing areas

7.8 Testing the completed tiling

7.9 Marbelite

7.10 Coatings and paints

7.11 Sheet linings to swimming pools

7.12 Glass-fibre polyester resin linings

7.13 Finishes to walls of pool halls

The roofs of swimming pool halls

7.14 General considerations

7.15 Pressurised roof voids

7.16 The warm-deck roof

Further reading

8 Water circulation and water treatment

8.4 Layout of treatment plant

8.5 Filtration and filters

8.6 Chemical dosing of the pool water

8.7 The disinfection of pool water

8.14 The base-exchange process for softening pool water

8.15 Sulphates in swimming pool water

Further reading

9 Notes on heating swimming pools and energy conservation

9.1 Heating open-air swimming pools

9.2 Heating the water in indoor swimming pools

9.3 Heating and ventilation of pool halls and adjoining areas9.4 Solar heating of swimming pools

Further reading

10 Maintenance and repairs to swimming pools

Maintenance of swimming pools

Repairs to external works: paving

10.6 Remedial work to insitu concrete paving for pedestrians10.7 Remedial work to insitu concrete paving for light commercialvehicles

10.8 Remedial work for precast concrete flag paving

10.9 Remedial work to precast concrete block paving

10.10 Remedial work to clay pavers

10.11 Remedial work to slippery paving

10.12 Preventing trips and falls

Repairs to external works: walling

10.13 Remedial work to free-standing walls

10.14 Remedial work to earth-retaining walls

Remedial work to pools under construction

10.15 General comments

10.16 Remedial work to thermal contraction cracks

10.17 Remedial work to drying shrinkage cracks

10.18 Remedial work to honeycombed concrete

10.19 Inadequate concrete cover to the reinforcement

Remedial work to existing pools: tracing leaks and investigations10.20 Introduction

10.21 Tracing leaks

10.22 General investigations

Remedial work to existing pools: repairs following leak tracingand investigations

10.23 Remedial work to leakage

10.24 Improving support to the pool floor

10.25 Structural lining to the pool shell

10.26 Remedial work to finishes

Further reading

Appendix 1 Conversion factors and coefficients

Appendix 2 Testing swimming pools shells, walkway slabs and other

wet areas for watertightness Commissioningswimming pools

IntroductionTesting new poolsTesting existing poolsThe leakage test procedureGeneral comments on testingWatertightness test for walkway slabs and other wet areasCommissioning swimming pools (filling and emptying)Appendix 3 Investigations, sampling and testing

General considerations

Sampling and laboratory testingCover-meter survey

Appendix 4 The consultant/designer as an expert witness

IntroductionThe form of the Expert’s ReportThe expert witness and the Construction Act 1996Appendix 5 Notes on safety in swimming pools

IntroductionWater depths for divingSigns for water depths in the poolOther safety signs

Outlets for water in the pool floorWater slides and play equipmentSlipping and tripping on floors of walkways,changing rooms etc

Chemicals in water treatmentAppendix 6 List of organisations relevant to this book

Since the third edition of this book was published in 1988 there have been nostartling changes in the materials used for the construction of swimming pools Asimilar comment can be made about the design of reinforced concrete swimmingpool shells

The number of swimming pools has continued to increase both in the publicand private sectors This is particularly so with private club leisure centres whichoffer a wide range of activities

There has been significant developments in the field of National Specificationsand Code of Practice relating to construction due to the intensive work on thepreparation of Euro Standards and Codes and the issue of Directives from theEEC The latter set out minimum quality standards for a wide range of constructionalmaterials, and establish the responsibility of suppliers and designers

Of particular importance are The Construction (Design and Management)Regulations 1994 which became completely effective in December 1995 TheseRegulations make people assess risks and take precautions rather than waiting todeal with problems when they occur They target the health and safety of thosewho build, maintain, install and demolish buildings and plant

The Construction Products Regulations came into force at the end of 1991 toimplement the Construction Products Directive The potential scope of theRegulations is very wide indeed as they are applicable to all types of productwhich are intended for permanent incorporation in buildings and civil engineeringworks The Regulations provide for the application of the European Communityregulatory mark—the CE mark—to construction products The Building ResearchEstablishment Information Paper IP 11/93 gives information on Ecolabelling ofbuilding materials and building products

The British Standards Institution emphasise that the Kite Mark will continue toensure that the level of quality is above the minimum legal requirements.Health and Safety Regulations have been extended and tightened up and there

is increasing awareness of the need for a more enlightened and professionalapproach to treatment of swimming pool water The Committee which producedthe publications for the Department of the Environment on the purification ofswimming pool water is no longer in existence It has virtually been replaced bythe independent Pool Water Treatment Advisory Group

It is important to observe recognised safety precautions when using certainmaterials, and also all types of plant and equipment.

Concrete itself is not a hazardous material; however, Portland cement whenmixed with water is highly alkaline (it has a pH of about 13.5) and is considered acaustic alkali It can cause burns to the skin, particularly to people who are vulnerable

to dermatitis A safety warning is included as an Appendix in all British Standardsfor Portland cement It recommends that precautions be taken to prevent dry cemententering the eyes, nose or mouth, and prevent skin contact with wet cement.Polymer resins are now widely used in construction and there are hazardsassociated with the use of some of these compounds Users should obtaininformation from the manufacturers and be aware of the requirements of thepublications of the Health and Safety Executive relating to the use of substanceshazardous to health

The corrosion of steel reinforcement continues to be the number one cause of

deterioration in reinforced concrete structures Research Focus, No 37, May 1999,

states that: ‘Corrosion of reinforcing steel in concrete structures…is estimated to

be costing the UK £550 million a year Many of these structures continue to requiremaintenance or replacement…’

It is therefore surprising that the protection of rebars by properly formulatedand applied epoxy resin coatings (see BS 7293 and ASTM Specification A775) isstill only used on a comparatively small scale in the UK

The author acknowledges with gratitude the encouragement, and many usefulcomments, he has received from his wife He also records the help he has beengiven by numerous people, organisations and firms, and in particular, David Butler

of the Sports Council, Andrew Alphick of the Pool Water Treatment AdvisoryGroup, Ralph Riley of the Institute of Baths and Recreation Management, GeoffreyRoberts and Jim Gordon of Buckingham Swimming Pools Ltd

a Building Permit under the Building Regulations, but planning permission may

be required It is therefore advisable for any one wishing to build a swimming pool

to consult their Local Authority, and also the water supply company as there may

be special requirements, such as metering of the supply, restriction on the amount

of water used etc

While there are regulations relating to swimming pools open to the public, thelegal control over the purity of water in pools for private houses, clubs and hotels

is minimal Recommendations for the treatment and quality of swimming poolswater have been issued by the Pool Water Treatment Advisory Group (PWTAG),namely the Pool Water Treatment and Quality Standards The PWTAG is anindependent body supported by all the organisations involved in the operation ofswimming pools

In the United States, the position is different; for example in Californiaregulations are in force which apply to all swimming pools except private poolsmaintained by an individual for use by his family and friends The regulationsspecifically apply to pools belonging to hotels, clubs, schools and healthestablishments Important aspects of design, layout, operation and maintenanceare detailed and clear directions given Requirements for the chemical andbacteriological quality of the water are included

1.2 Basic requirements for all swimming pools

The recommendations given below are intended to apply to all swimming poolsconstructed of what may be termed ‘long-life’ materials such as concrete

1 The pool shell (floor and walls) must be structurally sound

2 The shell must be watertight against loss of water when the pool is full or

partially full, and if constructed below ground level, against infiltration ofground water when the pool is empty or partly empty.

3 The internal surface of the floor and walls must be finished with a smooth,reasonably impervious, easily cleaned, attractive material The water must bemaintained at a proper standard of purity and clarity

4 A walkway of adequate width (minimum about 1.5 m), with a non-slip, easilycleaned and durable surface should be provided around the pool

5 A safety step (or ledge) should be provided on all the walls of pools used byyoung children and non-swimmers This safety step should be located notmore than 900 mm (0.9 m) below top water level (Figure 1.1)

6 A diving board should not be provided unless the dimensions of the divingarea and the water depth comply with the recommendations of the AmateurSwimming Association (ASA) For pools used for international divingcompetitions, the regulations of the Federation Internationale de NatationAmateur (FINA) should be followed

Figure 1.1 Sketch showing safety step.

1.3 Pools for private houses, clubs, hotels and

schools

1.3.1 Open-air pools: location

With pools in this category, there is generally a limited choice of location as theyusually have to be built on the same plot as the main building An exception isschool pools as these may form part of sports ground facilities which are likely to

be some distance from the school

For open-air pools for private houses, and hotels, the following points shouldreceive consideration

1 A position should be selected which receives as much sun as possible,particularly in the afternoon

2 The vicinity of large trees or potentially large trees should be avoided Treeroots can cause damage to foundations, and to drains and other pipelines.Leaves can cause discolouration of the pool water and staining of the poolfinish which is difficult to remove

3 It is advantageous to utilise a natural wind-break, such as a thick hedge, gardenwall, or part of the main building, and if it does not exist, to provide one aspart of the landscaping

4 The position of existing drainage, water supply, electricity and gas supplylines is important

5 Depending on the method of construction of the pool (see Chapters 4 and 5),access for materials and plant required for the construction can be critical

6 A small building (or room in the main building) will be needed for plant andequipment and storage of cleaning materials and the chemicals used for watertreatment

7 It is desirable for the distance from the changing accommodation to the pool

to be as short as practical bearing in mind the points mentioned above

8 For private houses and hotels, landscaping of the area in which the pool is to

be located should be given careful thought and professional advice is usuallyworthwhile

9 People often find it difficult to envisage from a two-dimensional sketch whatthe completed three-dimensional project will look like The cost of a simplemodel and/or an isometric drawing could be justified

Figures 1.2 and 1.3 illustrate alternative positions for a private pool

1.3.2 The shape and dimensions of swimming pools

The shape and dimensions of a swimming pool are mutually interdependent Theprimary use of the pool will be a major factor in determining both shape anddimensions

If the primary use is for training and swimming, then a rectangular shape isnormally chosen The length should be a simple fraction of 100 m, and the width

a number of swimming lanes which are usually to be 2.0 m wide (ASA for 25 mpools)

The materials used in the construction of the pool shell will also influence itsshape Pools constructed in insitu reinforced concrete can be of any shape, but thecost of a free-formed pool would be very high due to the cost of the formwork,compared with a pool constructed in sprayed concrete (shotcrete) But this costdifferential is influenced by the size of the pool, it being greater for smaller poolsthan for larger ones The smaller domestic and hotel pools, constructed in sprayedreinforced concrete can be any shape, with little difference in cost betweenrectangular and free-formed

Figure 1.2 Pool adjacent to building.

Figure 1.3 Pool near boundary of plot.

As these pools are likely to be used by children, non-swimmers and weakswimmers, the provision of a safety step around the pool at a depth not exceeding

900 mm (0.9 m) below top water level is strongly recommended This is a standardfeature of hotel pools in Switzerland (Figure 1.1)

1.3.3 Requirements for swimming

Even the smallest pool should be large enough for a swimmer to take severalstrokes; the minimum size would be about 6.00 m long by about 4.00 m widewith a minimum water depth of 1.00 m However, a water depth of 1.00 m is notsufficient from a safety point of view for even a very flat dive For generalcomfort, there should be an allowance of about 4.5 m2 for each person whowants to swim

1.3.4 Requirements for diving

The depth of water and the dimensions of the diving area for competitive diving arecovered in the UK by the requirements of the ASA For international events thesematters are covered by the world governing body, the Federation Internationale deNatation Amateur (FINA) There are minor differences between these two sets ofregulations but both provide adequate safety for diving in properly designed pools.The relevant publications of both organisations should be consulted and followed bythe designers of any swimming pool which is intended to include a diving board Thedesigner should check and comply with the latest recommendations

It is emphasised that the dimensions given are essential for safe diving from aposition not more than 1.00 m above the water level in the pool

A natural question is ‘What about diving from the sides of the pool?’ Theonly form of dive recommended into shallow water from the pool sides is what isknown as a flat racing dive, which can only be safely executed by experiencedswimmers; even then the minimum depth of water is 1.50 m, which must be

Table 1.1 Examples of rectangular swimming pools for private houses, hotels, clubs and

schools

maintained forward for a distance of 7.6 m and the water level in the pool shouldnot be more than 0.38 m below the pool edge These recommendations are given

by the courtesy of the Institute of Baths and Recreation Management

Diving should not be permitted nor attempted into pools which do not meetthe above recommendations Should an accident occur to a person diving into apool from a diving board which does not meet authoritative safetyrecommendations, the pool owner/manager may be faced with a claim thatwould be difficult to contest

1.4 Covered pools for private houses, hotels,

clubs and schools

There are obviously many advantages in having a covered swimming pool instead

of an open-air one A covered pool can be used in comfort 365 days a year comparedwith the ‘season’ for an open-air pool of about 150 days The conditions underwhich the pool has to operate are much less onerous; problems arising from freeze-thaw do not arise, staining of the walls and floor is much reduced, and discolouration

of the water from leaves and air-borne dirt will be eliminated

See Figures 1.5–1.6 for views of private house pools, and Figures 1.7–1.10 forviews of hotel, club, and school pools

A major problem with covered pools is the occurrence of condensation on thewalls, windows and ceiling, and, depending on the method of construction, withinthe roof space

The environment in the hall of a heated indoor swimming pool can be considered

as particularly hostile to many building materials; the air temperature is relativelyhigh—probably about 28 °C to 30 °C, and the relative humidity is also high, say,70–75% The surfaces in contact with the air in the pool hall will generally have alower temperature than the temperature of the air in the hall; if the air is saturated

Figure 1.4 Section through 25 m pool with diving pit.

Figure 1.6 Indoor private house pool Courtesy, Buckingham Swimming Pools Ltd Figure 1.5 Pool with Roman end and steps and fully automatic cover Courtesy,

Buckingham Swimming Pools Ltd.

Figure 1.8 Open-air pool at private club leisure centre Courtesy, Buckingham Swimming

Pools Ltd.

Figure 1.7 Indoor hotel deck-level pool with spa pool Courtesy, Buckingham Swimming

Pools Ltd.

Figure 1.9 Indoor, 25 m school pool Courtesy, Buckingham Swimming Pools Ltd.

Figure 1.10 Indoor hotel pool, Switzerland.

with water vapour, condensation will occur on the contact surfaces The temperature

at which condensation occurs is known as the dew point

The design and detailing of the roof requires special attention and this is discussedbriefly in Chapter 7

1.5 Teaching/learner pools

This section deals with general principles relating to layout and dimensions ofteaching pools irrespective of whether they belong to a school or form part of alarge swimming pool complex (leisure centre) run by a local authority

The first principle is that the pool must be absolutely safe for swimmers The pools are usually rectangular on plan with an almost levelbottom The water depth generally varies from 0.80 m to 1.00 m A useful size

non-is 12.00 m by about 7.0 m

There are often shallow steps into the pool extending the full length of theshort side

There are different opinions as to whether the walkway around the pool should

be lower than the deck to enable the teacher to carry out his duties without having

to bend down, or whether the pool shell should be elevated similar to thehydrotherapy pool shown in Figure 1.15 and briefly described in Section 1.9

In the UK, it is customary for the teaching pool to be quite separate from themain swimming pool so that the two different types of use do not interfere witheach other If the teaching pool is in a separate enclosed part of the main building,

it is usual for the temperature of the water and the air in the pool hall to be a fewdegrees above that in the main part of the building

1.6 Public swimming pools

1.6.1 Introduction

In the UK and most countries in the temperate zone, all new large swimmingpools which are publicly owned are covered to enable them to be used throughoutthe year

Table 1.2 Examples of dimensions of teaching pools

There are a number of large open-air pools in the UK which are owned bylocal authorities, but these were built many years ago, generally before theSecond World War These are only in operation for four or five months in theyear, usually from May to September A few of these are heated They arerectangular on plan and some contain sea water which contributes to a high rate

1 provision of adequate public transport;

2 provision for adequate car parking;

3 provision of public sewers (foul and surface water), water supply, electricity,gas and telephone;

4 adequate access for emergency services, fire brigade and ambulance;

Figure 1.11 View of part of pool at Bletchley Leisure Centre.

Figure 1.12 View of pool in Rushcliffe Leisure Centre Courtesy, British Cement Association.

Photographer, T.Jones.

Figure 1.13 View of pool in Swansea Leisure Centre with wave machine in operation.

Courtesy, British Cement Association Photographer, T.Jones.

5 sub-soil conditions including water table levels, presence of aggressivechemicals and presence of contaminated ground This is of particularimportance in view of the alleged shortage in the UK of ‘good building land’,which in some cases exerts pressure to build on land-fill sites TheEnvironmental Protection Act 1990 should be studied Requirement C2 ofSchedule 1 of the Building Regulations 1991 states that ‘precautions shall betaken to avoid danger to health and safety caused by substances found on or inthe ground covered by the building…’ Approved Document C, 1992 edition,sets out detailed requirements for dealing with containments Reference canalso be made to Section 4.2, and the list of Further Reading at the end of thischapter.

1.6.3 Types, shapes and dimensions

When the first edition of this book was published in 1971, the standard shape ofpublic swimming pools in the UK was rectangular or L-shaped Some large poolshad two shallow ends In L-shaped pools, the long leg can be used for swimmingand the short leg for diving

However, with the advent of the leisure centre, the shape, size and use of poolshave changed considerably Figures 1.11–1.13 show examples of public swimmingpools in leisure centres In these centres, it is usual for the main pool to be free-formed and incorporate a sloping ‘beach’ and the installation of a wave-makingmachine which is switched on for relatively short periods several times a day

It is emphasised that for competitive swimming, diving and aquatic sports, therequirements of the ASA (for national events) and FINA (for international events)must be fully complied with The requirements mentioned in this book are only afew of the very detailed requirements laid down by these two organisations Thefollowing are examples of some of these requirements:

1 For competitive swimming (national events), the water depth in front of thestarting blocks must not be less than 1.80 m and this must extend forward for

4 For life saving certificates, a water depth of 2.0 m is required and this mustextend for a length of 6.00 m over the full width of the pool

The provision of a diving pit as part of the main pool is deprecated as diving into

a pool in which persons are swimming is unpleasant and can be dangerous Thereare many advantages in having a separate diving pit which is used only for diving

By having a separate diving pit, swimming and diving events can be heldsimultaneously, and the same applies to training.

Pools intended for competitive swimming are normally 25 m or 50 m long with

a width based on a number of swimming lanes, either 2.0 m for national events or2.5 m for international events Reference must always be made to the latest edition

of the relevant regulations

For efficient emptying of the pool, hydraulic considerations require a gradient

of about 1 in 80 (25 mm in 2.00 m) The gradient should be uniform betweenclearly marked locations and depth markers on all walls are essential A furthersafety precaution is to provide non-slip tiles on the floor

The above comments on gradient do not apply to the steep slope down to adiving pit as shown in Figure 1.4

Water outlets in the floor at the deep end of the pool should be fitted with smallaperture gratings See Section 8.2.6

1.7.2 Walkways and wet areas

In this context ‘wet areas’ include all those areas, such as changing areas, walkwaysaround the pool, shower cubicals etc., which are made constantly wet by poolusers and by cleaners It is in these areas that injuries resulting from slipping aremost likely to occur There is a conflict between the need for a non-slip (or slipresistant) surface and the need for easy cleaning and efficient drainage (run-off)

At the time of writing, there does not appear to be any formal and recognisedgradients for floors in these areas

There is also the problem of ponding To avoid ponding, a gradient of about 1

in 40 (25 mm in 1.00 m) is normally required, but for safety a gradient of 1 in 60(25 mm in 1.50 m) is probably needed The frictional characteristics of the finishedsurface when in contact with the bare feet of pool users are relevant It should benoted that the gradient suggested here is considerably less than for the floor of thepool in Section 1.7.1

1.8 The drainage of walkways and wet areas

Where walkways and wet areas form part of a covered pool complex, thedrainage of these areas should not discharge into the water circulation system

of the pool but should be connected to the main drainage system of thebuilding

1.8.1 General comments

In some cases the public sewers are designed on the ‘separate’ system in whichsurface water is carried in surface water sewers, but in other areas, the seweragesystem is ‘combined’ and the foul and surface water is carried in the same sewer

It is important that an adequate number of inspection chambers/man-holes should

be provided and drainage system laid to gradients which will provide a self-cleansingvelocity

With open-air pools, the surrounding paving should slope away from the pool

1.9 Hydrotherapy pools

The advantages of carrying out special exercises under water have been known tothe medical profession for many years; the weight of the body is reduced by theweight of water displaced and thus movements are made much easier with lessmuscular effort

While spas in the UK have declined in popularity, this has not happened on thecontinent of Europe There, special health resorts, with names starting with ‘Bad’

in Germany, Switzerland and Austria, continue to flourish and attract large numbers

of visitors/patients The spas are mainly situated in beautiful country and make avery pleasant location for a holiday

Many of the special baths and swimming pools contain naturally heated highlymineralised water from springs, which in some places is slightly radio-active Thereare often a number of pools which operate at different temperatures and possesstherapeutic properties Under-water massage by powerful jets located at differentdepths below the water surface is a common feature of many of these pools Thelength of stay in the pool is strictly limited

Figure 1.14 shows a pool at a spa in Switzerland

Figure 1.15 shows a hydrotherapy pool at a school for pupils with severelearning difficulties The pool is 10 m×5.00 m and the depth varies from 0.90

m to 1.50 m It is a deck level pool and the water temperature is maintained

at 32°C

In the UK there are many therapeutic pools but these are mainly attached tohospitals, recuperation homes and similar institutions and are used for treatmentprescribed by a physician They seldom form part of a holiday resort

Special features to be taken into account in the design of such pools include thefollowing:

Figure 1.14 Open-air pool with wave machine in operation Bad Vals, Graubunden,

Switzerland.

Figure 1.15 Hydrotherapy pool in school for pupils with severe learning difficulties Courtesy,

Buckingham Swimming Pools Ltd.

1 The floor should have a flat gradient of about 1 in 80 (25 mm in 2.00 m)which should be adequate for emptying.

2 The floor of the pool and all wet areas should be finished with non-slip ceramictiles or ceramic mosaic

3 If the pool is not deck-level, then glazed ceramic scum channels should beprovided as these are more efficient in providing good water circulation thanskimmer outlets

4 The turn-over period (the time required to completely circulate all the water

in the pool) should not exceed 3 hours; some pools operate on a 1½hour cycle.See Section 8.2.1

5 The water temperature and the air temperature in the pool hall and changingareas should be maintained at a higher temperature than in normal swimingpools A water temperature of 30–32°C and an air temperature of 33 °C isadopted in many pools

6 All fittings should be corrosion resistant (austenitic stainless steel or bronze)

phosphor-7 As these pools will certainly be used by disabled persons, special arrangementsshould be included to enable such persons to enter and leave the pool easily;see also Section 1.11

8 If the pool contains saline water, then a detailed chemical analysis should

be obtained, including information on any variations in the concentrationand type of dissolved salts This is essential in order to decide whetherspecial protective measures are needed for the pool shell, finishes andfittings

1.10 Pools used for sub-aqua activities

Sub-aqua activities have become very popular in all parts of the world

Training in the sea, lakes and rivers in the UK and other countries in the temperatezone is often difficult owing to low temperatures, low visibility, currents etc Thus,there are many advantages in carrying out training in a swimming pool The BritishSub-Aqua Club (BSAC) requires that every beginner should receive basic training

In any event, these finishes require maintenance and repair in the course oftime Small damaged areas can be repaired under-water which eliminates the need

to lower the water level or empty the pool

The BSAC have published a booklet giving detailed information on allaspects of aqualung diving—see Further Reading at the end of this chapter

The BASC Code of Conduct contains some 21 directions, including emphasis

on the prohibition of dropping heavy equipment in the pool and anywhere inthe pool premises

As far as the pool itself is concerned, the requirements for sub-aqua activitiesare very modest The minimum dimensions required for a group lesson are 3.60m×5.00 m, with a minimum depth of water over this area of 1.50 m Theserequirements can be increased with advantage, with special reference to waterdepth to 3.50 m and if possible 5.50 m

Designers should contact the BSAC for their latest recommendations Figure1.16 shows sub-aqua training

1.11 Facilities for the disabled

The absolute need to provide satisfactory arrangements for disabled persons to usepublic swimming pools is now recognised

The specification and design of the necessary facilities require special study

at the design stage as it can be difficult and costly to provide these facilities at alater date

Work in this field is done by a number of organisations and reference should be

Figure 1.16 Aqualung training in public pool Courtesy, British Sub-Aqua Club.

Photographer, T.Jones.

made to BS 5810 1979 Code of Practice for Access for the Disabled to Buildings

and to the publications of the Thistle Foundation

1.12 Swimming pools with movable floors

The desirability of having separate pools for swimming, diving and teaching hasbeen mentioned earlier in this chapter Such separation entails additional capitalinvestment and increased operating and maintenance costs; also, the teaching anddiving facilities are only used from time to time

This led to the development of hydraulically operated movable pool floors andseparating walls The depth of water can be reduced over part of the pool by raising

a section of the floor thus forming a teaching/learner area

This feature has proved more popular in Europe than in the UK where thenumber of public pools with movable floors is small and very few have beenconstructed in recent years Figure 1.17 shows a movable floor in the raisedposition

Figure 1.17 View of movable floor in public pool Courtesy, Buckingham Swimming Pools

Ltd.

1.13 Wave-making machines

1.13.1 Introduction

The provision of equipment which generates artificial waves in swimming poolshas become increasingly popular in recent years When the first edition of thisbook was published in 1971, there was only one pool with wave-making equipment

in operation in the UK, namely the large open-air Portobello pool at Edinburgh,which was installed in 1936

During the past 25 years, wave-making equipment has been installed in manynew leisure centre pools

The wave-making machines are usually switched on at stated times for about15–20 minutes

There are several methods of creating artificial waves in swimming pools, themain methods being by (1) swing arm equipment, and (2) compressed air

1.13.2 Swing arm equipment

The makers usually make a model of the pool so that they can assess all importanthydraulic features, such as wave height, location of ‘breaking’ point, backwash,cross currents etc The shape and sloping floor create the effect of a sloping beachwith the waves breaking naturally The shape also provides adequate area of shallowwater for non-swimmers

The wave-making equipment consists of two swing arms which operate togetherbut not in complete unison For example, one arm oscilates at 17.5 oscillations perminute and the other at 18.0 oscillations per minute A specially designed screen isprovided in front of the wings

1.13.3 Compressed air equipment

There are a number of patented systems using compressed air to create artificialwaves

The creation of waves of the desired height and distance from crest to crest(wave-length) is not a simple matter and all relevant factors must be taken intoaccount This usually includes the making of a scale model

Figures 1.13 and 1.14 show pools with a wave machine in operation

RECOMMENDED PROCEDURE FOR GETTING A

POOL BUILT: CONTRACTS AND DEALING WITH

DISPUTES

1.14 Introduction

The recommendations which follow are intended mainly for private persons,club committees and owners of small hotels, although it is hoped that evenlarge hotel groups and local authorities will find some of the points mentioneduseful

1.15 Contracts: how to proceed

It is not recommended that a swimming pool should be built on a do-it-yourselfbasis Although there is a theoretical saving in capital cost the dividing linebetween success and failure is a very narrow one and the cost saving does notjustify the risk

The two procedures recommended are:

1 To engage a qualified professional person with proven experience in swimmingpool design and construction who will take responsibility for the preparation

of the design, drawings, specification and other contract documents, andobtaining all necessary permits The consultant should recommend a list of,say, three contractors, send out the invitations to tender, recommend to theclient the adjudication of the contract, certify the contractor’s accounts, andinspect the work at appropriate stages

The consultant should be a Chartered Civil or Structural Engineer orChartered Architect In the case of large contracts for public swimming pools/leisure centres, there will be several professional firms involved responsiblefor structural and civil design, heating and ventilating, electrical and mechanicaland architectural, and quantity surveyors; the Architect is usually the head ofthe team

2 To employ a consultant to advise on the selection of a suitable ‘package deal’contractor The names and addresses of swimming pool contractors can beobtained from the Swimming Pool and Allied Trades Association Theconsultant, in discussion with the client (referred to as the Employer in thecontract), should prepare a clear brief setting out the requirements (see Section1.2) It is important that the contractors should submit a list of recentlycompleted pools; these should be checked by site visits by the consultant,with the client

The financial standing of the selected contractors should also be checked,and information obtained on the extent the contractors employ sub-contractors

A test for watertightness should be clearly described and included in the

contract; see Appendix 2 at the end of this book for details of this test.The consultant’s brief should also include for periodic site inspections tohelp ensure that the contractor is carrying out the work in accordance with thecontract.

1.15.1 Insurance-backed guarantees and warrantees

In recent years there have appeared on the market ‘insurance-backed guarantees’.These are offered by contractors/sub-contractors and material suppliers claimingthat should the work prove defective, then the insurance company will provide thefunds to have remedial work put in hand in the event of the contractor/supplierfailing to do so This suggests that the client will avoid the necessity of legal action

to obtain redress These ‘guarantees’, which are sometimes referred to as

‘warrantees’, are stated to be valid for periods of 10–20 years from the completion

1.16 Dealing with disputes

The above may appear to be exaggerated, but experience suggests that caution andattention to detail is the best approach Irrespective of which procedure is adopted,

if things do go wrong, such as work unduly delayed, poor workmanship, the use ofsub-standard materials, the failure of the pool to pass the leakage test etc., thebuilding owner will find he is faced with the following limited choice:

1 He can accept the situation, which he would be most unwilling to do, or

2 He can instruct the contractor to put things right, in accordance with the terms

of the contract, and if he fails to do so he can follow the procedure laid down

in the Conditions of Contract

If the faults are serious, it is unlikely that even after completion of the remedialwork, the finished job will be as satisfactory as if it had been done properly thefirst time

One of the worst things that can happen is for the contractor to go intoliquidation during the contract The cost of employing another contractor tocomplete the project will be very high and the chance of obtaining financialcompensation from the original contractor is extremely small This is why it isimportant for the consultant not to feel obliged to recommend the acceptance

of the lowest tender even though the tenders are from a list which he hasdrawn up There can be many reasons why a contractor will submit an

exceptionally low price The client would be unwise to disregard hisconsultant’s advice in this matter.

The value of an experienced consultant, a properly drawn-up contract, and care

in the selection of the contractor cannot be over emphasised

1.16.1 General comments

The method of dealing with disputes which may arise during or aftercompletion of a contract will depend mainly on whether the contract comeswithin the scope of the Housing, Grants, Construction and Regeneration Act

1996 which came into force on 1 May 1998 (known as the ConstructionAct 1996)

If the contract falls outside the scope of the Act then dealing with disputeswould follow established procedure However if the contract falls within theAct, entirely new procedures would have to be followed Unfortunately, thewording of the Act in a number of important matters is lacking in clarity and

at the time of writing this book, there is little reported experience in theoperation of the Act

The Act covers a very wide field, but the construction of a private swimmingpool is likely to be outside the Act as it would most probably come under theexemption given to residential contracts

The coming into force of the Construction Act has necessitated the revision ofthe Standard Forms of Building Contract and Sub-Contract, and the ICE Conditions

The changes can be divided into three areas:

(a) The restriction of legal aid;

(b) The expansion of contingency fee arrangements (‘No win, No fee’) for allproceedings except crime and family;

(c) Fundamental changes to court proceedings which should decrease costs andincrease speed

In the main, all Personal Injury work will be excluded from the new Legal Aidstructure…’ Except in certain cases, ‘the case will be dealt by another route, e.g aconditional fee arrangement, or via alternative dispute resolution.’ (This change indealing with personal injury cases is likely to affect claims arising from accidents

in swimming pools.)

‘Even before litigation starts there will be changes in the manner in which

parties conduct themselves There will be a series of preaction protocolsdealing with various categories of litigation…There is a single objective to thenew court rules—to enable the court to deal with the cases justly Lord Woolf

felt that the two evils of modern litigation were delay and disproportionate

costs…

Expert evidence will be more restricted and may not be adduced without leave

of the court Normally experts will not be allowed to give oral evidence but willprovide a written report and answers to written questions put to them by the opposingparty…’

There will be considerable control of costs ‘Prior to taking interlocutory stepsdetails of the costs must be given to the other side…’

All the above changes face the test of practical use and there may well be furtherchanges in the light of experience

1.16.2 Notes on procedure for contracts outside the

construction Act 1996

As stated in Section 1.16.1 above, the situation may arise where the owner isfaced with the choice of accepting an unsatisfactory swimming pool or takinglegal action against the contractor, and/or the consultant A Solicitor experienced

in construction disputes would be able to advise the client on the appropriateprocedure The action to be taken is generally laid down in the GeneralConditions of Contract

Action against the consultant could arise if it was considered by the employer’sSolicitor that he had been guilty of professional negligence

The majority of construction contracts (prior to the 1996 Act), contain aprovision for referring disputes as a last resort to arbitration But subject tocertain conditions, a party can apply to the Court to have the matter settled byCourt action

It is important to remember that Arbitration can be more expensive than Courtaction as the Arbitrator has to be paid (Arbitrators fees are high), and payment has

to be made for the hire of the arbitration room Costs usually ‘follow the event’which means that the losing party may have to bear his own legal costs and those

of the other party Court judgments can be quite surprising This, together with thehigh cost of litigation, is no doubt why so many disputes are settled out of Court(about 75–80%)

In the event of Arbitration or Court action, the employer would beadvised by his Solicitor to engage a professional person to act as an ExpertWitness Some information of the duties of an Expert Witness are given inAppendix 4

In Court proceedings, difficult technical considerations can arise if adefence of ‘Limitation’ is put forward Such a defence is only likely to arisesome years after the completion of the pool A defence of limitation would

involve the Limitation Act 1980 and the Latent Damage Act 1984, and theexpert witness would be asked for his opinion on the following two issues:

1 When did significant damage first occur?

2 What was the earliest date on which the Plaintiff had both the knowledgerequired to bring an action for damages in respect of the relevant damage andthe right to bring such action?

Such questions give rise to very complex technical considerations to which there

is unlikely to be a clear-cut technical answer

Due to the enormous cost of High Court actions and the very considerabledelay which occurs between the time of the issue of the Writ and the handingdown of the judgment, proposals have been made in recent years to find alternativemethods of settling disputes This is generally known as ‘Alternative DisputeResolution (ADR)’

While the majority of cases in the Official Referee’s court and in arbitrationsettle before trial, few do so early enough to avoid the substantial costs incurred inthe preparations leading to trial

The essence of ADR is to create a framework in which the parties involved in adispute can reach a solution for themselves This usually requires the assistance of

a neutral third party

There are a number of ADR techniques which include:

Conciliation;

Mediation;

Mini-trial;

Expert fact finding and adjudication

The success of ADR depends entirely on the willingness of all parties to resolvetheir dispute in a mutually satisfactory way, and this requires considerable giveand take Some references on ADR are given under Further Reading at the end ofthis chapter

1.16.3 Notes on procedure under the construction Act

The Adjudicator must then be appointed within seven days of the issue of anotice by the party wishing for adjudication The Adjudicator must reach adecision on the dispute within 28 days of referral, unless both parties agree to

an extension of time With the consent of the referring party, the Adjudicatormay extend the 28–day period by up to 14 days

The decisions of the Adjudicator are binding until the dispute is finallydetermined by legal proceedings or by arbitration or by agreement between theparties The orders of the Adjudicator must be complied with and they are bindinguntil the dispute is finally determined

The Act contains numerous new concepts and conditions and anyoneintending to have work carried out by contract after 1 May 1998 shouldseek legal advice on whether the contract will come within the scope ofthe Act

Reference can usefully be made to the publication Construction Briefings, issued by Merricks, Solicitors, Chelmsford and London, and Notes of a

Seminar on the Construction Act, given by Lawrence Graham, Solicitors,

London

Further reading

General

British Sub-Aqua Club Pools for Sub-aqua Use.

Cottam, G Adjudication under the Scheme for Construction Contracts Thomas Telford,

London, 1998.

Department of the Environment Building Regulations (Amendment) Regulations

1998, S.I 2561—Revision to Part M, Access and Facilities for Disabled

People.

Institute of Baths and Recreation Management Practical Leisure Centre

Management, Vol 2.

Institute of Baths and Recreation Management Diving in Swimming Pools.

International Board for Aquatic, Sports and Recreation Facilities International Standards

Swimming Pools: Part B, Construction, Finish and Equipment, 1977.

Sports Council Safety in Swimming Pools, 1998.

State of California, Department of Public Health Laws and Regulations Relating to

Swimming Pools, excerpts from the California Health and Safety Code and the

California Administrative Code.

Swimming Pools and Allied Trades Association Swimming Pool Guide, 1995.

Construction Act 1996

Merricks, Solicitors Construction Briefing—The Housing Grants, Construction and

Regeneration Act 1996, Merricks, Chelmsford and London, May 1998.

Lawrence Graham, Solicitors Four papers at a seminar on The Housing Grants,

Construction and Regeneration Act 1996, Lawrence Graham, London, July 1998.

Health and safety and environmental law

Fink, S Health and Safety Law for the Construction Industry, Thomas Telford, London,

1997.

Health and Safety Executive Slips and Trips HS (G) 155.

Stubbs, A Environmental Law in the Construction Industry, Thomas Telford,

London, 1998.

Alternative dispute resolution

McKenna and Company, Solicitors Law Letter, Autumn/Winter 1989, McKenna, London,

The expert witness

Newman, P Professional liability of expert witnesses, Journal CIArb, August 1993, pp.

173–81.

Lord Taylor The Lund lecture—The expert witness, Journal CIArb, May 1995, pp 113–17.

The Times, Law Report: 6 Oct 1999: Court of Appeal Judgement 27 July 1999; Stevens v Gullis (Pile third party).

EEC construction legislation

Department of the Environment Construction products directive, Euronews, Construction ,

Special supplement, September 1991.

Kay, T and Wyatt, B European Standards for protection and repair, J Concrete, September

1997, pp 11–17.

Taylor Joynson Garrett, Solicitors The Construction (Design and Management) Regulations,

1994, Construction Review, Issue No 1, 1995.