15.10.2016 - Ausgabe: 5/2016

Artificial turf, hybrid turf or natural grass? – Finding the right surface for the sports ground

Conversion of sports fields and football pitches in particular is a very current trend. Following the many conversions in the last years and the modern sports fields created in this way, the clubs involved have been able as a rule to generate many new members and to become better positioned in the sport. In the wake of these developments, many other clubs have felt themselves under pressure to modernise their own facilities in order to avoid being at a competitive advantage in the long term. In this way, new sports fields have been created in many places. The choice of correct playing surface, however, is not always easy. Artificial turf? Hybrid turf? Natural grass? It is not always costs which are the decisive factors.

Up until a few years ago the picture in many places was very similar. The sports clubs, in general as today, these were football clubs, had either a clay pitch or a natural grass pitch or both – the clay pitch for training (in rural areas, often a second grass pitch) and the natural grass pitch for matches and sporting events. Where matches were played on a clay surface, this was not as popular with the players, but was easier to care for and more resistant to weathering. This evened out the conditions in a regional context if the condition of the sports facilities were not taken into account.
The picture today is essentially somewhat different with artificial turf pitches, hybrid sport turf pitches, natural grass pitches and clay playing surfaces. All these have advantages and disadvantages but they are not really balanced out. The players have a choice and many change the club if they have the opportunity to play on a more comfortable or preferred pitch in a different place. As the clubs do not want to lose members however, and in fact perhaps even want to gain new ones, modernisation of playing fields are pushed ahead in many places. But the question remains for many community authorities and clubs; which is the best suited surface for which sports facilities? A growing number of options and suppliers are available in the market. In order to make the right choice, six main criteria should be taken into account: duration of use, renovation costs, maintenance outlay, playing behaviour, weatherability and sustainability. In the following, the different kinds of artificial, hybrid sport and natural grass pitches are compared to each other according to the criteria given above.

 

Duration of use

Duration of use should be taken as the first criterion as the different surfaces already differ greatly in this point. Clubs looking for a sports surface which can be used more than 1200 hours a year can only really look at an artificial turf pitch where more than 2000 hours of play a year are easily possible. As a rule, a natural grass pitch provides only 600 – 800 hours of play, a hybrid sports turf up to 1200 hours. This means that an accurate overview of the number of hours use throughout the year needs to be drawn up in order to precisely calculate the number of hours of use.

 

Conversion costs

Money is naturally the number one criterion many cases. There are also some differences with regard to conversion costs. It must basically first be checked whether or not the existing drainage systems can still be used. If some elements of the existing sports field are still usable, this can reduce the conversion costs. The least expensive concept is known as "green ashes" which means the direct transformation of a clay surface into a natural grass pitch. The clay surface is not removed, it is mixed with sand and fertiliser and hardy sport-resistant grass planted. This concept has existed for some time and with conversion costs from 120,000 Euros, takes first place in the price ranking. Conversion to a "conventional" natural grass pitch, sown from seed or laid as a roll of turf, usually costs in the region of 170,000 – 250,000 Euros. Hybrid sport turf pitches cost around 250,000 to 350,000 Euros depending on system and artificial turf pitches around 400,000 to 600,000 Euros.

 

Maintenance costs

The fairy tale about artificial turf pitches needing no maintenance work remains obstinately lodged in many people's minds, despite many efforts to counter this. Artificial turf pitches need regular care and maintenance work using appropriate machinery. Calculations have been made by the KGSt (German community agency for administrative management) which report annual maintenance costs of natural grass pitches (and therefore hybrid sports pitches) to be around 2.24 €/m² and for artificial turf pitches 1.92 €/m². These figures are collected from surveys and show that the difference in care and maintenance costs between natural and artificial turf is not as large as often assumed.

 

Ball behaviour

Football is a natural grass sport and ball behaviour on all other pitches is measured against this original feeling. While, for instance, hockey sports are now played completely on artificial turf pitches, a natural grass pitch in an optimum condition is still the most favoured surface for a game of football. A hybrid sport turf pitch may cause a different playing feeling or ball behaviour, depending on the actual type used, although it is very similar to a natural grass pitch. During recent renovation work at the Allianz Arena football stadium in Munich, a natural grass pitch was laid again due to the hardness of the previous hybrid sport turf. On third and fourth generation artificial turf pitches, ball behaviour is very natural and the playing feeling reported as positive by the majority of players. Here again, development work is still oriented towards natural grass pitches which will probably continue to take first place in the list with regard to this criterion.

 

Resistance to weathering

Come sun or rain – a sports field is used under different weather conditions. In very intense sunshine an artificial turf pitch may become uncomfortably hot, so that a good irrigation system is also worthwhile for this kind of pitch. All playing surfaces are slippery in the rain and a good drainage system is always important. The advantage of an artificial turf pitch compared to other playing surfaces is that it needs no recuperation time after lasting periods of heat or rain. Natural grass, and therefore also hybrid sports turf, can suffer serious damage from the effects of weather even though a hybrid sports turf pitch remains much firmer and more stable than a pure grass pitch in rainy weather.

 

Sustainability

Natural grass sports pitches are the most efficient with regard to ecological and economic sustainability. As a naturally renewable raw material, only the use of fungicides and exhaust emissions from machinery can be mentioned as negative factors in the ecological balance, and strictly speaking, water consumption in summer. Due to the use of artificial fibres, a hybrid sports turf pitch comes of worse. While a natural grass pitch has no determined "best before" date, hybrid sports turf will sooner or later need to be replaced. Problems have also been reported with landscape protection authorities who are not happy with artificial fibers being introduced into natural substrate and further tests will be necessary in this field.

Sustainability of artificial turf, on the other hand, is not so positive. As an synthetic material, the artificial turf surface is not only questionable from an environmental point of view, it must also be replaced after 15 years use at the latest, which also causes additional costs (200,000 Euros on average) and comprehensive and correct disposal of the replaced material.

 

… and clay?

With regard to some of the criteria mentioned here, a clay playing surface comes up positive, but it will always fails in one major point – the playing feeling. Players prefer other kinds of surface and as mentioned, can even change clubs for this reason. In many cases, parents will not register their children with clubs playing on clay pitches if an alternative club with an artificial, hybrid or natural grass pitch is available locally; and even though clay pitches are excellent from the point of view of cost-to-performance ratio, they have passed their zenith. They are furthest away from the optimum case of a natural grass pitch and this cannot be compensated by the other positive factors. In ten years, clay sports surfaces will probably be as good as extinct in an urban setting.

 

Summary

The comparison based on these criteria has shown that all kinds of sports surface considered have advantages and disadvantages. To what extent the individual criteria have priority must be decided individually in each case, some factors are automatically excluded. In most cases, the duration of use and costs for conversion and maintenance of the new pitch are surely the strongest criteria. The players' opinion should not be underestimated however, as many clay surfaces would otherwise still remain in many places. In the end, the goal is to inspire as many players as possible for sport itself – in the end possibly the most important criterion – and the trend towards conversion and modernisation of sports facilities is definitely leading in this direction.

TT