Court Testing

Tennis is played on a variety of surfaces, more so perhaps than any other sport. The properties of each surface influence the style of play and affect the quality of performance. The following notes seek to outline and quantify the key properties that affect play, with the aims of:

1. Establishing a minimum level of quality and encouraging high-quality workmanship.

2. Improving standards, based on what is currently achievable by experienced contractors using quality materials and conventional methods at reasonable cost.

3. Enabling comparisons between courts, giving court constructors, suppliers and end-users a common language to describe different products.

4. Protecting contractors against unreasonable demands.

It is further intended to provide a guide to tests suitable for tennis courts for end-users, tournament organisers and court proprietors, in addition to acting as a manual for test houses, suppliers and constructors. The methods described herein will be particularly applicable to surface testing in:

- Venues for elite-level tennis tournaments, such as the Davis Cup.
- National/regional tennis centres.
- Other tennis facilities where the standard of play demands the specification of precise playing characteristics.
- Research and development laboratories.

The ITF has identified ‘definitive’ and ‘predictive’ methods for testing the key properties of a surface. Definitive methods are recommended for laboratory testing and on-site testing of courts for professional competition. Predictive methods provide a more economical means of on-site testing.

IMPORTANT NOTE: Whilst these test methods are recommended by the ITF, they are not mandatory.

The properties of court surfaces are known to change, due to factors such as ambient conditions, use and maintenance. Unless otherwise stated, this section refers to court surfaces which have been given sufficient time to stabilise (as advised by the contractor or supplier).

Follow the links to the right to see details of all court tests.

On-site and Laboratory Testing

It is preferred that surfaces are tested in situ, although it is accepted that the testing of samples in a laboratory may be more practical (and effective) in some cases. The test method for court pace (ITF CS 01/02) is applicable to both laboratory and on-site testing.

On-site testing

Following installation, on-site tests should not be carried out until the court surface has been given sufficient time to stabilise. Typically, the playing surface of an acrylic court requires a week to stabilise, whereas clay or artificial grass may need several months. Factors that affect stabilisation time include: surface type, site conditions, e.g. climate and shade, usage and maintenance. The stabilisation time should be agreed with the contractor in advance of testing. Prior to testing, the court shall be prepared using the manufacturer's, supplier's and/or contractor’s procedures.

Testing commences with a visual inspection of the court. At a minimum, the court should have a uniform appearance, with no gaps between joins or crack, and straight court markings.

During testing, the prevailing environmental conditions should be recorded, including:

- Maximum and minimum temperature of the air, surface and test balls.
- Maximum and minimum relative humidity.
- Maximum and minimum atmospheric pressure.
- Condition of the surface, i.e. dry, damp, etc.

Unless the surface is designed to be damp/wet when in its optimum condition, tests should be made when the surface is dry. To minimise the effects of changes in ambient conditions, the test should be completed as soon as is reasonably possible. Tests for court pace ITF CS 01/02 should not take place if the average temperature of the test balls cannot be maintained within the range 10-30°C.

Tests conducted at above 1,219 m (4,000 feet) should use balls recommended for play at high altitude as defined in the Rules of Tennis.

Tests for court pace ITF CS 01/02 and ball rebound should be carried out in at least four different locations. Recommended locations – representative of high, medium and low usage areas, and court markings – are shown in figure 1 (the arrowheads indicate the location and direction of testing).

Note: In addition to the recommended locations, any area of particular concern, such as joins between modular systems, should be tested.

Figure 1. Recommended locations (and test directions) for on-site testing.

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Laboratory testing

For tests in the laboratory, the test specimen must be conditioned at the test temperature (23 ± 2°C) for a minimum of 3 hours.

Test specimens for laboratory testing should be flat and have minimum dimensions of 0.5 m × 0.5 m, and include any relevant supporting layers or aggregate used in construction.

Note: Loose-laid specimens should be anchored at the edges.

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Test balls

A high specification ball is required for court testing to reduce the effect of ball properties on the measurement of surface characteristics (see table 1).

Type of ball Pressurised
Mass 57.6 ± 0.3 g
Diameter 6.60 ± 0.05 cm (2.598 ± 0.020 inches)
Forward Deformation 0.64 ± 0.04 cm (0.252 ± 0.016 inches)
Return Deformation 0.94 ± 0.14 cm (0.370 ± 0.055 inches)
Rebound 141 ± 1 cm (55.5 ± 0.4 inches)
Woven Cloth 55 ± 5% wool, 45 ± 5% nylon
Table 1. Ball specification for surface testing

For all tests, balls should be kept pressurised in their cans at 23 ± 2°C prior to testing and pre-compressed before use. Pre-compression is intended to remove temporary ‘set’ in the ball, which may occur during prolonged storage. Pre-compression consists of compressing the ball by approximately 2.5 cm on each of three diameters at right angles to one another in succession; this routine is carried out three times (nine compressions in all). Firing the ball three times at an oblique angle onto a smooth, rigid surface using a ball projection device at 30 ± 2 m/s is an optional means of applying precompression.

Balls should not be subjected to more than 12 impacts each, excluding any precompression impacts, to ensure that their original properties are retained throughout testing.

Average ball temperature should be recorded to the nearest degree Celsius for each test location/sample. An infrared thermometer, calibrated to ± 1°C, is recommended for this purpose.

Test reports

Each test performed requires a report to document the results and conditions. The
test report should contain all relevant information, including:

- Reference to the ITF test method and code.
- Identification, and detailed description, of the surface composition, including supporting layers, and its condition.
- Information on the test environment: temperature; humidity; atmospheric pressure; altitude; venue.
- Statement of the ball brand name and country of manufacture.
- All results.
- Overall result, typically the average and variation of the measurements (for comparison against the category or recommendation).

Disclaimer: This section does not intend to, nor does it in fact, establish any binding rules or regulations relating to acceptable standards for tennis courts. This section is not part of the Rules of Tennis. The ITF cannot be held responsible for, and accepts no liability for, the failure of any product or service manufactured, produced or provided according to the information given in this section or for any acts or omissions made in reliance upon it or in connection with it. In relation to the contents of this section and/or any act or omission made in reliance upon it or in connection with it, the ITF accepts no liability for any loss of income or revenue, loss of business, loss of profits or contracts, loss of anticipated savings, or for any indirect or consequential loss or damage of any kind however arising and whether caused by tort (including negligence) breach of contract or otherwise, even if foreseeable. Furthermore, the ITF cannot be held responsible for, and accepts no liability for, any injury sustained during the testing of surfaces using the methods described herein, or for any injury sustained while playing on a court that meets any guideline or recommendation in this section.