Which types of synthetic turf surfaces are suitable for which pitch sports?
For football and rugby, “third generation” or 3G surfaces are most appropriate. These may also be described as long pile synthetic turf.
3G pitches are all capable of being played on using studded footwear although certain types, such as metal studs, are not advised. 3G surfaces for football are usually from 40mm to 60mm pile height. Surfaces for rugby must have a pile height ≥ 60mm and have a HIC ≥ 1.3m which will usually mean that a good quality shockpad has to be used to achieve this.
For hockey, non-filled, water-based, sand-filled or sand-dressed surfaces are preferred.
Detailed guidance is available in the document “Selecting the Right Artificial Surface for Hockey, Footfall, Rugby League and Rugby Union”, developed by Sport England in consultation with key sports governing bodies. Click here to access the document:
There is a large number of synthetic turf systems on the market, most of which look quite similar but may be made of different materials, manufactured by different techniques and designed for use in different ways. There are many fibre producers and even more carpet manufacturers and installers. It is therefore essential to establish or specify the precise materials and carpet types required for specific sports governing bodies’ performance requirements to be met. The preferred playing characteristics should be specified at tender stage, and each tender submission should be accompanied by independently certified proof of the proposed system’s performance together with a reference sample.
Non-filled systems differ distinctively in design and appearance from filled pitches. There are many products on the market; the very first synthetic turfs were unfilled and there are still some systems available now which are installed with no irrigation system. There are a number of systems available of the long pile length variety designed predominantly for soccer use which have a very dense pile and do not require sand or rubber infill.
Many unfilled products require the use of water to change their surface properties when in use. They are often referred to as “wet fields” or “water-based pitches”, and these types of products are in the main used for hockey. The water is applied via an irrigation system to the surface immediately before play. The presence of water reduces the player/surface friction, modifies the speed of the hockey ball and cools the surface in hot climates. When designing a non-filled installation, due consideration must therefore be given to the means of applying sufficient water over a short period of time. A direct result of the incorporation of a suitable irrigation system and the denser pile construction is reflected in the cost of installation being considerably higher than sand-filled systems.
Sand-filled systems are significantly less expensive than non-filled surfaces as the pile density can be reduced due to the sand infill. The tufting method is the most widely available. Polyolefin, polyamide and mixed co-polymer yarns are used. The silica sand infill should consist of non-abrasive, non-staining, well rounded, dust-free particles of uniform grading and density, free from extraneous contaminants. The sand infill is normally taken to within 3 mm of the fibre tips. The sand and fibre combine to provide the characteristics of the playing surface and it is essential that the level of sand fill is maintained throughout the life of the facility. Sand-filled systems do not normally require to be irrigated in the UK climate.
A derivative of the sand-filled system is the so-called “sand-dressed” carpets. These are intermediate in properties between traditional filled and non-filled carpets. They have a shorter, denser pile than the standard filled turf systems with a reduced quantity of sand fill.
Sand-dressed systems are commonly specified as alternatives to the non-filled, irrigated fields for hockey.
The long pile turf system (3G) has found favour with the football and rugby governing bodies and has been approved for football and rugby at the highest level.
Surfaces falling into this category differ from standard sand-filled systems in the height of pile, commonly up to 65mm long, and the infill used, normally 2/3 of the pile height. The infill to the 3G system is normally designed to provide some of the shock absorption by using rubber granules. The rubber granules are sometimes mixed with sand or incorporated with sand in layers. Among the benefits this system brings to sports such as football and rugby, is that a full football stud and metal BS kite-marked rugby studs can be used on the surface and the football/surface performance properties are closer to natural grass than previous synthetic turfs.
What is the budget cost for a synthetic pitch, and how might it vary?
The cost of a full-size synthetic pitch can typically vary between £400,000 and £700,000. There are many different factors that will influence the cost of such a pitch including:
Extent of earthworks or improvement to ground conditions, if required
Type and height of fencing
Type and illumination level of floodlighting
Synthetic pitch base type
Irrigation, if required
It is important to obtain realistic budget quotations and for these to take into account the contingencies that may be required to resolve any issues that may occur particularly during the earthworks and drainage phase of the contract.
Before a final price can be offered by a contractor there would have to be sufficient information available for them to price accurately. This would include a full site investigation of ground conditions under the proposed pitch.
To which Standards should a synthetic pitch be built?
The Standards to which a pitch should be built will depend on the user requirements and sports to be played.
FIFA Quality Pro is usually installed for professional clubs for pitches that are to be used for match play. FIFA Quality is often installed for pitches that have heavy community usage.
It should be considered and allowed for that, in order to maintain certification of FIFA pitches, a strict maintenance regime and ongoing testing and validation is required. A FIFA Quality Pro pitch is, for that reason, expected to lose performance at that level sooner than a FIFA Quality pitch.
FIH has various Standards that a pitch can be built to depending on the level of play required.
Global : Non-filled, irrigated short-pile turf
National: Sand-filled or sand-dressed turf
Multi-sport: Sand-filled, sand-dressed or long pile (3G)
The type of pitch base required is just as important as surface choice when choosing a synthetic pitch and guidance should be sought from consultants that have experience and knowledge of civil engineering in this regard.
Will the project need planning permission?
In most cases, unless it is a resurfacing project, full planning permission will be required. The planning authorities will usually provide consultation, and it is always sensible to find out about planning requirements at an early stage before monies are expended on site investigation etc. The planning authority would be able to give an opinion on whether a project is likely to encounter planning issues that may unfortunately mean a proposal is not feasible.
How should we choose a pitch contractor?
The members of SAPCA’s Pitch Division have been verified as having the requisite experience and technical knowledge to undertake the design and construction of synthetic pitches. As members of the Association, they are required to comply with the requirements of the Associations various Codes of Practice, and adhere to SAPCA’s Code of Professional Conduct.
Which is better - an engineered base or a dynamic base?
Both systems have merit in the right circumstances.
An engineered base has always been considered to have superior longevity and the capacity to sustain its performance over a longer period of time than a dynamic base.
Dynamic bases are generally specified to reduce the initial cost of a pitch build. It should be noted however that they may require rectification when resurfacing in future years.
What is the purpose of a shock-pad, and is it necessary?
The introduction of a resilient layer between the base and the synthetic turf is used to provide a degree of comfort to players and to create defined performance and safety characteristics for specific sports. Its correct design may also help systems to meet the required playing characteristics over longer periods of time. There are various ways of achieving this resilient layer, with assorted laid in-situ shock-pad systems, prefabricated or combinations of both. Typical components of in-situ systems are rubber crumb/shred mixed with a resin binder. In the case of pre-fabricated systems, the shock-pad is delivered to site as rolls or tiles of prefabricated material. In the case of in-situ systems the components are mixed on site and laid to form a continuous layer of material.
Each system, whether in-situ, composite pad or roll form, will have different features and benefits which the manufacturer will confirm and demonstrate before a choice of system is made. Careful evaluation of systems and laying processes is essential when making comparisons between products. Experience has shown that carpet and shock-pad movements may prove more likely if the shock-pad is not fully jointed and/or is not dimensionally stable.
What type and height of fencing will we need?
For football and hockey pitches it is usual to have 3m high fencing down the side lines and 5m fencing at the goal ends. However, if the pitch is adjacent to a road or other properties it may be necessary to install 5m fencing all around the facility. Higher fencing can also deter intruders if the area has a vandalism problem.
What drainage is needed for a synthetic turf pitch?
A suitable drainage scheme should be designed and installed which will:
Ensure that all surface water is removed from the site at a rate which will safeguard against surface flooding occurring.
Not allow excess water to remain present in the construction which might result in a reduction of the load-bearing capacity of the formation or in any frost damage to the construction.
Protect the installation from the effects of ground or surface water from the surrounding areas.
Meet the requirements of the Environmental Agency or Local Water Authority. This aspect is usually required at planning stage for most facilities, therefore a drainage design will normally form part of the client’s design criteria.
A basic design will have lateral drains incorporated beneath the pitch, the centres of which should be determined by the composition of the subsoil and the designed infiltration and outfall rates. Centres usually range from 5 m to 15 m. The ends of lateral drains should be capped to prevent contamination, and connectors should be used when joining lateral drains to collector drains. Collector drains should be located on the outside of the perimeter edging.
What sort of infill should we choose?
Most 3G surfaces require a free draining silica sand base layer topped off with a soft infill material.
There are various types of infill available, such as:
SBR (granulated rubber tyres to a specific grading) is usually the most cost effective. It should be noted that some users complain of the smell if used in indoor areas.
EPDM or coated SBR can be manufactured to the required gradings and will be coloured.
Other types e.g. cork.
It is important that the 3G surface has been tested using the type of infill required. Your consultant should be able to provide advice on this.
What quality control measures are important for the project?
The quality of the workmanship should be checked at various ‘key’ stages during the construction process against the specification for the works. Such stages may include the following:
At completion of the formation, to check size, levels, gradients and bearing capacity.
At completion of the construction of the drainage system, to ensure that all connections have been made and that the correct falls have been made in pipe work.
At completion of the installation of the sub-base, to check that the correct depth has been installed and that level tolerances have been met.
At completion of the base again to check that level and thickness requirements have been met.
At completion of the shock-pad to check thickness and tensile strength.
At completion of the surface to ensure consistency of infill depth across the pitch and conformity to the appropriate performance standard required.
When the pitch is handed over, what are the most important things to check to ensure it has been installed to the right quality?
The specification for any pitch should include the specific sports performance requirements dictated by the sport or sports to be played. These performance requirements are specified in a number of ways, either to the relevant sports governing body requirements or to British/European standards. Independent performance testing should be carried out on the completed facility, where possible prior to handover. It is recognised, however, that some types of synthetic turf do not reach their normal playing performance until the pile filling has settled into the carpet pile which may take up to a couple of months to occur. The purpose of these tests is to ensure that the completed facility meets the requirements of the works specification, and if funded by a sports governing body, that their requirements have been met. Once handed over, the facility should be tested prior to the end of any defects liability or maintenance period and also at the end of the warranty period if a performance-based warranty was required. Furthermore, some sports governing bodies require annual or biennial retesting for certain levels of competition.