Cluj Arena is a multi-use stadium in Cluj-Napoca, Romania. It is to be ranked as an Elite UEFA stadium. Its capacity is 30.200 people - making it the 2nd largest stadium in Romania. The architects were tasked with creating a stylish roof capable of coping with exceptionally high wind loadings while providing natural light for the pitch and specta- tor stands and complimenting the overall aesthetics of the stadium. Multiwall polycarbonate sheets were the cho- sen material to glaze the inner edge of the canopy roof.
The architects were faced with the challenge of creating a symbolic contemporary landmark. They wanted to cre- ate a structure with fluid and flowing of forms with a strong connection to the meander of its neighboring river. The architectural theme for this project was transparency. The walls of the stadium were cleverly designed with a transparent ‘skin’ to allow free and amazing views of the external surroundings from inside the arena during the day and allowing spectacular views of the shows and events inside the stadium when lit at night.
The vision of the architects originally consisted of the impressive curved canopy roof of the stadium being com- pletely clad with metal. After site visits it became clear that metal wasn’t the best solution because of the ovoid shape of the roof and its large curvatures. The location of the stadium meant that the roof would have to be able to cope with extraordinary wind loads (of over 5kN/sqm) and heavy snow loading, using metal would result in heavy and costly constructions for the supporting structure.
Polycarbonate sheets used in the project are light in weight, have a high resistance to impact and damage and are easy to maintain. The metallic silver colour of the PC sheets which were used blends in perfectly with metal allow- ing a seamless transition between the corrugated steel roof and the polycarbonate glazing. It also follows the trans- parency theme refining the vision of the architect allowing a very interesting penetration of light which would not have been possible with a completely metal roof.
The decision to use multiwall polycarbonate sheets instead of metal was based on the many benefits the material offers, including:
- Strength for high wind and snow loading;
- Increased spanning between supports;
- Light transmission capabilities;
- Fire performance;
- Ease of installation and maintenance;
- Heatguard metallic silver finish;
- Cost effectiveness;
- Versatility for freedom of design.