( Disclaimer & Health Warning: See also cautionary advice on the Building & Repairing Eton Fives Courts)
Eton Fives Court | Court Diagram | Court Plan - 1 2 3 4 5 6The following notes have been prepared at the request of the Eton Fives Association and address specification requirements for the playing surfaces (walls and floors) of new and refurbished courts.
A previous report by G F Blackledge, Chief advisory Engineer to the South East Region, Cement and Concrete Association, "Recommendations for Fives Court Renderings" forms the basis of section A. References to British Standards within that document, have been updated and additional information has been included to reflect both current practice and the experience of the writer from involvement in the refurbishment of two courts and the construction of one new court at Ipswich School.
A drawing showing court dimensions has been prepared and is also available, reference 558/01. The dimensions given, are based on an earlier drawing provided by the EFA with conversions to metric figures and on a survey of competition courts at Eton College.
Where reference is made to British Standards, the standards quoted are the latest editions. At the time of writing, many standards are under review, particularly as part of the work of the European Committee for Standardisation (CEN). Specifiers should check the latest editions of all standards before proceeding.
Whilst every effort has been made to address the conditions likely to be faced by specifiers, care should be taken to select methods appropriate to the particular circumstances of each project, particularly when dealing with the preparation of existing surfaces and backgrounds.
Further information on cement, concrete, screeds and cement based renderings can be obtained from:
The British Cement Association, Century House, Telford Avenue, Crowthorne, Berkshire Tel:01344 762676.
A charge may be made for technical advice.
The Concrete Society. Tel: 01443 237210 by subscribers to their Advisory Service.
The prime requirement of the finished applied rendering is that it shall be uniformly hard, smooth, level and of a consistent colour. The achievement of these requirements will be dependent on the materials which are used and the workmanship employed. Hard, smooth surfaces such as those required can only satisfactorily be achieved using a cement rich rendering. Unfortunately, such mixes tend to be prone to cracking due to shrinkage resulting from drying, and surface cracking due to over-trowelling, this latter being necessary to achieve a hard and compacted dense surface. The following clauses have been drafted to ensure the use of the correct materials and as a guide to the workmanship which will be necessary.
The cement used should be ordinary portland cement complying with the requirements of BS 12:1989. The suppier of OPC should be registered as being of Assessed Capability under the British Standards institution. Registered Firms scheme with assessment against the appropriate part of BS 5750: Quality Systems.
2.02 - Where the final surface is required to be coloured, a coloured Portland cement, in which the pigment is incorporated during manufacture and complying with clause 3.3 of BS12, shall be used. The mixing of a pigment with OPC on site should not be permitted.
2.03 - All cement should be stored off the ground, stacked clear of walls, away from all damp surfaces and undercover. Stacking should be arranged so that bags can be taken out for use in the same order in which they were delivered.
The sand should be well graded, clean and complying with BS 1199:1976 including amendments 1-3(1984-86) Building Sands from Natural Sources. Note: sea sands and sands containing calcium chloride, dirt or clay should be avoided.
2.05 - Aggregates should be stored on clean, hard, dry ground and protected from contamination by soil or any harmful substances.
Lime used to improve placticity should not exceed the proportions given in 7.00 below. Lime should be hydrated lime powder complying with BS 890: 1995 Specification for Building Limes. Lime for the works should be the subject of third party certification of product conformity with BS 890 coupled with assessment of the supplier's quality system against the appropriate Part of BSEN ISO 9000.
No admixtures should be permitted.
Metal lathing, where required, should be stainless steel expanded metal lath complying with the requirements of BS 1369: Part 1: 1987.
3.01 - The nature of the background to which a rendering is applied is important, and from the point of view of rendering treatment there are the following classes:
3.02 - Dense, strong and smooth materials.
Such materials as high density clay bricks or blocks and dense concrete have low porosity, little suction and smooth surfaces that afford no mechanical key. Sometimes, therefore. difficulties are found in securing satisfactory bond between the rendering and the background, so that some artificial means of ensuring good bond is often necessary. Spatterdash treatment is recommended, although for dense concrete, hacking or bush hammering may be advisable.
3.03 - For concrete backgrounds it is important to control suction just before application of renderings. Dry concrete often creates a suction sufficiently high to impair its bond to the applied finish. Treatment with a wet brush will convert the suction and remove any loose material at the same time. Care should be taken not to apply so much water that some is left on the surface.
3.04 - Moderately strong and porous materials.
Most bricks and blocks, other than the dense type considered under 3.02 above, fall into this class. These have relatively high suction, generally good mechanical key and good adhesion for renderings.
4.01 - It is of the utmost importance that surfaces to be rendered should be in proper condition and cleaned of all dust and loose particles. If any dubbing-out is needed, it should be done well in advance of the application of the first undercoat, using a mix stronger and coarser than the first undercoat but not stronger than the background. If the thickness needed is greater than 16mm if should be built-up in two or more coats, each not more than 16mm thick.
Joints of brickwork to be rendered should be raked out during construction to a depth of not less than 13mm.
Laitance and efflorescence should be removed. Ridges or fins left on concrete by shuttering imperfections should be removed before cleaning down. A spatterdash treatment should be applied by throwing, either from a trowel or scoop. A mix should be made to a wet consistency, almost a slurry, but varied according to the suction of the backing material. The whole surface should be just covered with a thin layer, 3mm to 6mm thick, and no attempt should be made to level or smooth the coating in any way before applying the undercoat. Under hot, dry conditions the spatterdash should be wetted to ensure satisfactory hardening.
4.04 - If the background includes junctions between dissimilar meterials, especially if this includes straight joints, stainless steel expanded metal lathing should be fixed across the junction in a continuous band of minimum width 300mm (15Omm each side of junction) and fixed along each edge at maximum 100mm centres. It is most important when plastering over metal lathing, to allow sufficient time for each coat to dry and shrink before applying the next coat.
5.01 - The rendered treatment should not be less than two coats, applied at intervals to allow each coat to dry out before applying the next. One undercoat followed by a finishing coat will normally be adequate. Any spatterdash coat is considered already to have been applied as 4.03 above.
The undercoat provides a means of straightening or levelling an uneven surface and provides a surface of even suction and good adhesion for the finishing coats. The undercoat should not exceed 16mm or be less than 9mm in thickness of any part.
The thickness of the final coat will normally be 6mm - 9mm as finished.
6.01 - The mix for each successive coat should never be of a type richer in cement than the mix used for the coat to which it is applied.
When used to provide a key, spatterdash should consist of one part Ordinary Portland Cement to 1.5 - 2 parts sand by volume.
The mix proportions should consist of one part Ordinary Portland Cement to 0 - 0.25 part hydrated lime to 3 parts sand by volume.
7.01 - The proportions given in 6.00 are by volume. The sand is assumed to be damp and no allowance for variation in bulking is practicable. Mixing should be done in a mechanical mixer and should continue until the materials are uniformly mixed. Water should then be added as required and the mixing continued until the whole is of a uniform and workable consistency. The materials should preferably be weigh batched but gauge boxes may be used provided that the method of filling is consistent through the course of the work. Mixer containing cement should be used within two hours of the addition of the cement and in no circumstances should material that has partly set or dried be retempered; if should be discarded. When lime in the form of putty made from quick lime or hydrated lime is required to improve the plasticity the proportion should not exceed 0.25 part of lime to 1 part of cement by volume.
8.01 - Work should not be started until the background has been properly prepared.
8-02 - The undercoat should be kept thoroughly damp for 24 hours after application by continuous spraying with water. It should then be left for at least 14 days before applying an additional undercoat or the final coat. It should be left rough and open from the edge of the laying trowel and, after if has been left long enough to set firm, the surface should be combed or scratched, care being taken to leave the scratch marks sufficiently deep to provide a key for the following coat, but not so deep as to penetrate the rendering.
8.03 - If a second undercoat is necessary, the first undercoat should be brushed down to remove any dust and loose particles and should be completely saturated with clean water such that it is in a damp condition before the application of the subsequent undercoat. Subsequent undercoats should be 9mm to 13mm thick and the surface, when firm, should be combed or scratched. It should be kept continuously wet for a period of 24 hours and left to dry out for at least 14 days before applying the final coat.
8.04 - The finishing coat should be not less than 6mm or more than 9mm thick and should be applied with a laying trowel and finished with a wood float. After the surface of the final coat has become just firm it should be trowelled using a steel trowel in order that the surface maybe compacted to a dense composition. Overworking with the steel trowel when the final coat is not firm enough will draw to the surface an excess of laitance; this shoud be avoided at all costs.
8.05 - The final coat should be kept saturated by spraying continuously for a period of 7 days before it is allowed to dry out.
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