Swimming Pools

Copyright 2000 Philip H Perkins
Swimming Pools
Fourth edition
Philip H Perkins





London and New York

Copyright 2000 Philip H Perkins
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)
Copyright 2000 Philip H Perkins
Contents
Preface
1 The planning and layout of swimming pools
General considerations
1.1 Introduction
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 schools
1.5 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
Further reading
2 Basic characteristics of the materials used in the construction of
swimming pools
2.1 Introduction
2.2 Portland cements
2.3 Aggregates from natural sources for concrete and mortar
2.4 Admixtures
Copyright 2000 Philip H Perkins
2.5 Additions
2.6 Water for mixing concrete, mortar and grout
2.7 Steel reinforcement
2.8 Spacers
2.9 Non-ferrous metals
2.10 Bimetallic corrosion
2.11 Curing compounds for concrete and mortar
2.12 Polymers
2.13 Reactive resins
2.14 Joint fillers
2.15 Joint sealants

2.16 Ceramic tiles
2.17 British standards and euro codes
References
Further reading
3 Factors affecting the durability of reinforced concrete and
cement-based materials used in the construction of swimming pools
3.1 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 treatment
3.8 Moorland water and the Langelier Index
3.9 Alkali-silica reaction
Further reading
4 Construction of swimming pool shells in insitu reinforced concrete
4.1 Introduction
4.2 Site investigations
4.3 Under-drainage of site
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 ground
4.11 Construction of the walls of the pool
Copyright 2000 Philip H Perkins
4.12 Construction of walkway slabs and floors of wet changing

areas
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
Further reading
5 Construction of swimming pool shells in reinforced sprayed
concrete and other materials
Reinforced sprayed concrete (shotcrete)
5.1 Introduction
5.2 Design and specification
5.3 Methods of application
5.4 Execution of the work
5.5 Thermal insulation
5.6 Pipework
5.7 Testing for watertightness
5.8 Under-water lighting
Swimming pools constructed with reinforced hollow concrete
block walls and insitu reinforced concrete floor
5.9 Introduction
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
5.17 Thermal insulation
Sandwich type construction with insitu reinforced concrete
core wall and concrete blocks as permanent form work

5.18 Introduction
5.19 Construction of the floor
5.20 Pipework
5.21 Construction of the walls
5.22 Under-water lighting
5.23 Finishes to floor and walls
5.24 Testing for watertightness
5.25 Back-filling around the walls
Copyright 2000 Philip H Perkins
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 rock
5.32 Pools constructed of precast post-tensioned concrete units
5.33 Pool shells of steel
Further reading
6 External works
6.1 General considerations
6.2 Paving
6.3 Surface water drainage
6.4 Walling
Further reading
7 Finishing the pool shell and associated structures; problems with
pool hall roofs
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
Copyright 2000 Philip H Perkins
8 Water circulation and water treatment
Water circulation
8.1 Flow-through pools
8.2 Pools where the pool water is in continuous circulation
8.3 Ducts for pipework
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
8.8 Chlorination
8.9 Ozone
8.10 Bromine

8.11 Chlorine dioxide
8.12 Metallic ions (silver and copper)
8.13 Ultra-violet radiation
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 areas
9.4 Solar heating of swimming pools
Further reading
10 Maintenance and repairs to swimming pools
Maintenance of swimming pools
10.1 General considerations
10.2 Routine supervision: smaller pools
10.3 Shut-down periods
10.4 Algal growths: prevention and removal
10.5 Foot infections
Repairs to external works: paving
10.6 Remedial work to insitu concrete paving for pedestrians
10.7 Remedial work to insitu concrete paving for light commercial
vehicles
10.8 Remedial work for precast concrete flag paving
Copyright 2000 Philip H Perkins
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 investigations
10.20 Introduction
10.21 Tracing leaks
10.22 General investigations
Remedial work to existing pools: repairs following leak tracing
and 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. Commissioning
swimming pools
Introduction
Testing new pools
Testing existing pools
The leakage test procedure
General comments on testing
Watertightness test for walkway slabs and other wet areas
Commissioning swimming pools (filling and emptying)

Appendix 3 Investigations, sampling and testing
General considerations
Copyright 2000 Philip H Perkins
Sampling and laboratory testing
Cover-meter survey
Appendix 4 The consultant/designer as an expert witness
Introduction
The form of the Expert’s Report
The expert witness and the Construction Act 1996
Appendix 5 Notes on safety in swimming pools
Introduction
Water depths for diving
Signs for water depths in the pool
Other safety signs
Outlets for water in the pool floor
Water slides and play equipment
Slipping and tripping on floors of walkways,
changing rooms etc.
Chemicals in water treatment
Appendix 6 List of organisations relevant to this book
Copyright 2000 Philip H Perkins
Preface
Since the third edition of this book was published in 1988 there have been no
startling changes in the materials used for the construction of swimming pools. A
similar comment can be made about the design of reinforced concrete swimming
pool shells.
The number of swimming pools has continued to increase both in the public
and private sectors. This is particularly so with private club leisure centres which
offer a wide range of activities.
There has been significant developments in the field of National Specifications

and Code of Practice relating to construction due to the intensive work on the
preparation of Euro Standards and Codes and the issue of Directives from the
EEC. The latter set out minimum quality standards for a wide range of constructional
materials, 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. These
Regulations make people assess risks and take precautions rather than waiting to
deal with problems when they occur. They target the health and safety of those
who build, maintain, install and demolish buildings and plant.
The Construction Products Regulations came into force at the end of 1991 to
implement the Construction Products Directive. The potential scope of the
Regulations is very wide indeed as they are applicable to all types of product
which are intended for permanent incorporation in buildings and civil engineering
works. The Regulations provide for the application of the European Community
regulatory mark—the CE mark—to construction products. The Building Research
Establishment Information Paper IP. 11/93 gives information on Ecolabelling of
building materials and building products.
The British Standards Institution emphasise that the Kite Mark will continue to
ensure 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 professional
approach to treatment of swimming pool water. The Committee which produced
the publications for the Department of the Environment on the purification of
swimming pool water is no longer in existence. It has virtually been replaced by
the independent Pool Water Treatment Advisory Group.
Copyright 2000 Philip H Perkins
It is important to observe recognised safety precautions when using certain
materials, and also all types of plant and equipment.
Concrete itself is not a hazardous material; however, Portland cement when
mixed with water is highly alkaline (it has a pH of about 13.5) and is considered a

caustic 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 Standards
for Portland cement. It recommends that precautions be taken to prevent dry cement
entering the eyes, nose or mouth, and prevent skin contact with wet cement.
Polymer resins are now widely used in construction and there are hazards
associated with the use of some of these compounds. Users should obtain
information from the manufacturers and be aware of the requirements of the
publications of the Health and Safety Executive relating to the use of substances
hazardous 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 require
maintenance or replacement…’
It is therefore surprising that the protection of rebars by properly formulated
and applied epoxy resin coatings (see BS 7293 and ASTM Specification A775) is
still only used on a comparatively small scale in the UK.
The author acknowledges with gratitude the encouragement, and many useful
comments, he has received from his wife. He also records the help he has been
given by numerous people, organisations and firms, and in particular, David Butler
of the Sports Council, Andrew Alphick of the Pool Water Treatment Advisory
Group, Ralph Riley of the Institute of Baths and Recreation Management, Geoffrey
Roberts and Jim Gordon of Buckingham Swimming Pools Ltd.
Copyright 2000 Philip H Perkins
Chapter 1

The planning and layout of
swimming pools
GENERAL CONSIDERATIONS
1.1 Introduction

In the United Kingdom, the construction of the shell of a swimming pool (without
ancillary buildings such as plant house, changing rooms etc.) is unlikely to require
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, the
legal control over the purity of water in pools for private houses, clubs and hotels
is minimal. Recommendations for the treatment and quality of swimming pools
water have been issued by the Pool Water Treatment Advisory Group (PWTAG),
namely the Pool Water Treatment and Quality Standards. The PWTAG is an
independent body supported by all the organisations involved in the operation of
swimming pools.
In the United States, the position is different; for example in California
regulations are in force which apply to all swimming pools except private pools
maintained by an individual for use by his family and friends. The regulations
specifically apply to pools belonging to hotels, clubs, schools and health
establishments. Important aspects of design, layout, operation and maintenance
are detailed and clear directions given. Requirements for the chemical and
bacteriological 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 pools
constructed 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
Copyright 2000 Philip H Perkins
partially full, and if constructed below ground level, against infiltration of
ground 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 be
maintained at a proper standard of purity and clarity.
4. A walkway of adequate width (minimum about 1.5 m), with a non-slip, easily
cleaned 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 by
young children and non-swimmers. This safety step should be located not
more 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 diving
area and the water depth comply with the recommendations of the Amateur
Swimming Association (ASA). For pools used for international diving
competitions, the regulations of the Federation Internationale de Natation
Amateur (FINA) should be followed.
Figure 1.1 Sketch showing safety step.
Copyright 2000 Philip H Perkins
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 they
usually have to be built on the same plot as the main building. An exception is
school 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 should
receive 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. Tree

roots can cause damage to foundations, and to drains and other pipelines.
Leaves can cause discolouration of the pool water and staining of the pool
finish which is difficult to remove.
3. It is advantageous to utilise a natural wind-break, such as a thick hedge, garden
wall, or part of the main building, and if it does not exist, to provide one as
part of the landscaping.
4. The position of existing drainage, water supply, electricity and gas supply
lines 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 and
equipment and storage of cleaning materials and the chemicals used for water
treatment.
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 usually
worthwhile.
9. People often find it difficult to envisage from a two-dimensional sketch what
the completed three-dimensional project will look like. The cost of a simple
model 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. The
primary use of the pool will be a major factor in determining both shape and
dimensions.


Copyright 2000 Philip H Perkins
If the primary use is for training and swimming, then a rectangular shape is
normally 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 m
pools).
The materials used in the construction of the pool shell will also influence its
shape. Pools constructed in insitu reinforced concrete can be of any shape, but the
cost 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 cost
differential is influenced by the size of the pool, it being greater for smaller pools
than for larger ones. The smaller domestic and hotel pools, constructed in sprayed
reinforced concrete can be any shape, with little difference in cost between
rectangular and free-formed.
Figure 1.2 Pool adjacent to building.
Copyright 2000 Philip H Perkins
Figure 1.3 Pool near boundary of plot.
Copyright 2000 Philip H Perkins
As these pools are likely to be used by children, non-swimmers and weak
swimmers, 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 standard
feature 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 several
strokes; the minimum size would be about 6.00 m long by about 4.00 m wide
with a minimum water depth of 1.00 m. However, a water depth of 1.00 m is not
sufficient from a safety point of view for even a very flat dive. For general
comfort, there should be an allowance of about 4.5 m
2

for each person who
wants to swim.
1.3.4

Requirements for diving
The depth of water and the dimensions of the diving area for competitive diving are
covered in the UK by the requirements of the ASA. For international events these
matters are covered by the world governing body, the Federation Internationale de
Natation Amateur (FINA). There are minor differences between these two sets of
regulations but both provide adequate safety for diving in properly designed pools.
The relevant publications of both organisations should be consulted and followed by
the designers of any swimming pool which is intended to include a diving board. The
designer should check and comply with the latest recommendations.
It is emphasised that the dimensions given are essential for safe diving from a
position 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?’. The
only form of dive recommended into shallow water from the pool sides is what is
known as a flat racing dive, which can only be safely executed by experienced
swimmers; 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
Copyright 2000 Philip H Perkins
maintained forward for a distance of 7.6 m and the water level in the pool should
not 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 meet
the above recommendations. Should an accident occur to a person diving into a
pool from a diving board which does not meet authoritative safety
recommendations, the pool owner/manager may be faced with a claim that
would 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 compared
with the ‘season’ for an open-air pool of about 150 days. The conditions under
which 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 for
views of hotel, club, and school pools.
A major problem with covered pools is the occurrence of condensation on the
walls, windows and ceiling, and, depending on the method of construction, within
the 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 relatively
high—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 a
lower 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.
Copyright 2000 Philip H Perkins
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.
Copyright 2000 Philip H Perkins
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.
Copyright 2000 Philip H Perkins
Figure 1.9 Indoor, 25 m school pool. Courtesy, Buckingham Swimming Pools Ltd.

Figure 1.10 Indoor hotel pool, Switzerland.
Copyright 2000 Philip H Perkins
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 discussed
briefly in Chapter 7.
1.5 Teaching/learner pools
This section deals with general principles relating to layout and dimensions of
teaching pools irrespective of whether they belong to a school or form part of a
large swimming pool complex (leisure centre) run by a local authority.
The first principle is that the pool must be absolutely safe for non-
swimmers. The pools are usually rectangular on plan with an almost level
bottom. The water depth generally varies from 0.80 m to 1.00 m. A useful size
is 12.00 m by about 7.0 m.
There are often shallow steps into the pool extending the full length of the
short 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 the
hydrotherapy 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 the
main swimming pool so that the two different types of use do not interfere with
each 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 few
degrees 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 swimming

pools which are publicly owned are covered to enable them to be used throughout
the year.
Table 1.2 Examples of dimensions of teaching pools
Copyright 2000 Philip H Perkins
There are a number of large open-air pools in the UK which are owned by
local authorities, but these were built many years ago, generally before the
Second World War. These are only in operation for four or five months in the
year, usually from May to September. A few of these are heated. They are
rectangular on plan and some contain sea water which contributes to a high rate
of general deterioration.
In Europe, mainly in Switzerland and Germany, in spas, there are large open-
air heated pools, some with wave-making machines.
Figures 1.11–1.13 are examples of pools in public leisure centres.
1.6.2

Location
It is not possible to lay down detailed rules for the location of public
swimming pools, but the following are matters which should receive careful
consideration:
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.
Copyright 2000 Philip H Perkins
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.

Copyright 2000 Philip H Perkins