Pitch protection in place at EURO 2012 stadia
Seven of the eight stadia being used as venues for the current European Football Championships have underpitch heating systems installed by REHAU. The stadia in Warsaw, Poznan, Wroclaw, Gdansk, Kiev, Lviv and Kharkiv have all been built or renovated during the last two to three years, and all have the company's pipework installed beneath the playing surface.
The systems ensure a constantly playable football pitch throughout the year – not just keeping the ground from freezing during the winter in a reliable and turf-friendly way, but also providing the drainage routes that maintain the permeability of the surface so that the pitch does not become waterlogged during periods of heavy rain.
The technology behind underpitch heating is very similar to that of underfloor heating and cooling. For its underpitch heating systems, REHAU uses PE-Xa pipes made from the same polyethylene used in its underfloor heating systems because they offer the durability that is required.
The pipework is typically installed at a depth of 25cm below the grass root level and is clamped to REHAU fixing rails at precisely pre-defined intervals. This ensures, for example, that the turf in the penalty area will remain free from ice, while the grass roots on the penalty spot do not suffer from excessive heat.
The systems are controlled by a weather dependent regulating facility, which maintains the turf surface temperature at a maximum of 2˚C, with the temperature limited at root level to prevent damage to the grass itself. A mixture of glycol and water circulates through the pipes in a closed loop, with the glycol acting as an antifreeze agent allowing the heating to be completely turned off, for example, during the Christmas playing break which operates in many European countries, with no risk of the pipes freezing due to the cold.
Ground staff can maintain the turf using standard machinery with virtually no risk of damaging the heating pipework but, if an accident should occur, then the Everloc compression sleeve jointing system, which is used on all REHAU’s pipework, enables rapid access for repairs without the need to remove large quantities of earth.
At the European Championships, one of the more unusual installations was at the new national stadium in Warsaw where the turf is heated by a concrete slab beneath the playing surface. This concept – TABS (thermally activated building structures) uses the mass of solid building components to create a giant thermal energy store with pipework embedded within the concrete and the temperature regulated by the flow of cold or hot water. This stadium is a multi-functional arena, which will not only be used for matches, but is also intended as a venue for concerts, so the concrete slab allows the turf to be laid or removed as needed.
There is growing international acceptance of the concept of underpitch heating to avoid the costs and disruption associated with the postponement of matches. The German Football Association (DFB) has already made it a standard requirement that stadia in the first and second German Bundesliga install turf heating, and in Ukraine, turf heating is mandatory for all stadia that hold Champions League and Europa League matches.