YOUR FORUM FOR PLAY, SPORTS UND LEISURE AREAS
This finding, dating from the mid 19th century and attributed to the English social reformer John Ruskin, is now even more valid than ever. Even though the cost-effectiveness of synthetic turf has been discussed for a long time, too often it is still the price alone which is taken as the decisive criterion for placing a contract. Quality is often only given cursory attention under the motto, "you can play well on it". This is the only explanation for the, in some cases frivolous, handling of the topic of synthetic turf and in particular, its powder filling.
In comparison to other sport surfaces such as natural turf or clay, tendering for a synthetic turf pitch is more comprehensive and in some areas, also more difficult. The root cause of this fact is the complexity of the material made up of plastic fibres, supporting fabric, in some cases secondary backing and back coating. In addition to this there is also often the varying problematic of a granulate filling.
One direction which is unfortunately often taken during tendering is definition of one particular product in which special trust is placed. This can be perhaps based on a seminar where the manufacturer participated, perhaps because someone has already played on this kind of pitch. In order to provide other manufacturers or suppliers with the (theoretical) possibility of entering an offer, the performance requirements are often supplemented with the phrase "or equivalent". Procedural misgivings about a product-neutral tender apart, the problems of determination and evaluation of the "equivalency" of the products offered is completely underestimated. In this case, the supplier is now obliged within the framework of his offer, to prove that his products are just as good as or, depending on the point of view, just as bad as the defined product – verification which is difficult to provide, especially in the field of synthetic turf.
At the same time, the German tendering and contract regulations for construction project management (Vergabe- und Vertragsordnung für Bauleitungen, VOB), prohibits a decision based on price alone, by stipulating that other evaluation factors such as quality, for example, must also be taken into consideration (VOB/A § 16 Paragraph 6 No. 3). It is even explicitly stated that the lowest offer is not solely decisive for awarding the contract. Consequently, a contract must be awarded not to the lowest bid tendered, but to the most economic one. This however, requires that the building contractor or planner has comprehensive knowledge of the topic of artificial turf and causes additional time and effort in the tendering and evaluation of bids.
Fundamentally, for every new contract, suppliers should be requested to provide proof of the suitability, environmental compatibility and quality assurance of the turf products they offer. In Germany since October 2011, the relevant regulations are given in the standard DIN-SPEC 18035-7 which was drawn up by the German institute for standards (Deutschen Institut für Normwesen e.V., DIN) in cooperation with all interested parties as the previously valid standard DIN V 18035-7, no longer mirrored the actual state of the art after a period of nearly a decade. No turf product should be used for which no corresponding test reports can be provided, or for which the single test reports and confirmation documents do not clearly refer to each other. Technical data sheets, possible created by the manufacturers themselves, are not test reports or confirmation documents according to DIN SPEC 18035-7. In order for the values given in the test reports to be checked for feasibility, it is recommended to request a sample of the turf product. In practical tests, a sheet-of-paper sized sample (DIN A4) has proved to be suitable for checking a wide range of test values. A sample of the powder filling material should also be requested for powder-filled turf products.
Basing a call for tenders on the standard DIN SPEC 18035-7 alone however, will also not lead to the required success. In attachment A, which is only for information purposes, a list of total 10 different grades of turf is given. It can quickly be seen that synthetic turf is not just synthetic turf. If this overview is limited to powder-filled products, the selection is reduced to eight grades of artificial turf. Further limitation to quartz sand or sand/rubber filled products reduces the list to four grades. In order to ensure that all suppliers have the same prerequisites, it is at least necessary to state which kind of surface is required. Mentioning a product name however, is unnecessary. Along with the conventional details of the tender such as submission of the above-mentioned test reports and confirmation documents, any other evaluation criteria should be mentioned in the documentation of the call for tenders. A prerequisite for this is that the criteria and quality ratings or priorities have already been decided during preparation of the call for tenders. In fig. 1, examples of criteria and their valuation are given. These will be looked at briefly in the following:
Price: Either the unit price of the corresponding position or the overall price of the offer can be evaluated. This should be determined during the preparation of the call for tenders. With a call for tenders involving trade separation, for example, prices for the artificial turf sector can be compared as the overall price per square metre of turf. Within the framework of a general tender, there is basically no other alternative than to evaluate the individual prices of the corresponding positions, as otherwise, the evaluation becomes distorted to the influence of other prices. In the evaluation, the lowest price is given the highest marks and the most expensive product the lowest marks!
Pile weight: The pile weight indicates how much yarn material is used in the manufacture of the turf. In contrast to the old standard DIN V 18035-7 where the pile layer weight was required, the backing material of the synthetic turf is now also taken into account even though this is not an actual user surface. The pile weight of a turf is always higher than the pile layer weight. As the pile material is one of the most expensive components of an artificial turf, a product with a large amount of pile material should be given higher points than one with less material.
Number of tufts: Expressed in a simple way, the number of tufts is obtained by multiplying the number of tufts in a line with the number of lines and expresses the pile density of the artificial turf. Here again, it is considered that the more dense the pile material the better, as life expectancy of the turf is dependent on the yarn used and the density of the pile. In addition, infill material is retained better by denser pile, which means that the amount of maintenance work required is also reduced.
Secondary backing: The dimensional stability of a synthetic turf pitch is particularly dependent on the secondary backing material. As fabric provides greater stability than nonwoven material, it is also given better marks.
In order to avoid possible misunderstandings with regard to later calculation of the evaluation points, it is recommended to explain the process with a short example as included here (fig. 2).
Price:
Lowest price per m² € 15.00 = 100.00 % x factor (5.00) = 500.00 evaluation points
Highest price per m² € 17.50 = 85.71 % x factor (5.00) = 428.55 evaluation points
Pile weight:
Highest pile weight.1100 g/m² = 100.00% x factor (2.60) = 260.00 evaluation points
Lowest pile weight. 900 g/m² = 81.82% x factor (2.60) = 212.73 evaluation points
Fig. 2: Calculation example
The selected evaluation criteria and factors are always subjective estimations from the person writing the bid for tenders. This can and should therefore, be adjusted individually to meet the objectives in each case. In addition, it is also possible to include further evaluation criteria, such as the kind of tape, fibre structure, and the distance between lines of tufts or pile height, in a call for tenders. Other features of a synthetic turf pitch, such as perforation of the backing, are of less importance as sufficient values are given in corresponding regulation standards. In the case of perforation of the backing, this would refer to water permeability.
Figure 3 shows an example of how a fictive call for tenders should be written. The key figures given in the four offers for synthetic turf are real values, which have been changed and renamed for reasons of data protection. In this example Supplier A has given one main and one secondary offer with the two products "FuBa" and FuBa Top". At the same time, Supplier B as general contractor, has also offered the surface "FuBa Top" of Supplier A but at a slightly higher price as he has added additional costs, for example for coordination of the work or general overhead costs, onto the price of the turf. Supplier C takes second place with his offer and the material "KSR One", i.e. it is not the least expensive bid.
During a comparison of the bids, along with the general check, the factors to be evaluated such as price, pile weight, number of tufts and secondary backing are determined from the bids tendered and from samples provided, and the values entered into an evaluation matrix. After this has been carried out, the material "FuBa Top" provided by Supplier A takes first place for the criteria "Price" and "Number of tufts". After the pile weight has been taken into consideration however, Supplier C with the synthetic turf "Next Generation" takes first place overall and it is clear that use of a heavier garn results in a higher pile weight. Consequently, in relation to all evaluation criteria, Supplier C has provided the most economic tender and should be awarded the contract to supply and lay the artificial turf. As can be seen from the example provided, compared to the gross tender result, (total Supplier A, "FuBa Top": 156,187.50 €, minus total Supplier C, "KSR One": 159,757.50 €), the contract is awarded to an offer which is 2.29% more expensive.
As can be seen from this example, evaluations based only on price misjudge the fact that the difference between individual turf materials is based on several factors. Confirmation of equivalence is already not possible for the three synthetic turf materials offered.
It is naturally possible to make a product neutral call for tenders for a synthetic turf surface, although this requires the corresponding building contractor or planner making the call for tenders, to have corresponding expert knowledge. The specification that not necessarily the least expensive offer is awarded the contract is regulated by the VOB directives. The most economic tender, taking all points of view of the requirements into consideration, should be accepted as, "When you pay too little, you sometimes lose everything because the thing you bought was incapable of doing the thing it was bought to do". (John Ruskin).
