National Stadium for 2008 Olympics features ETFE roof and PTFE ceiling

Beijing N&L Fabric Technology Co. Ltd. | Beijing, China

Covertex GmbH | United Kingdom

The Beijing National Stadium, which won an Award of Excellence in the architectural structures category of the 2008 International Achievement Awards, was the center of the Beijing 2008 Olympic Games. The roof is ETFE and the acoustic ceiling is PTFE. The main function of the outer ETFE layer is to make the roof weatherproof, to protect the spectators and the roof structure — including the technical instruments — from precipitation. The inner PTFE layer ensures excellent acoustical and lighting conditions for the stadium, and it provides shade for the spectators. It also gives the stadium space a homogeneous, slowly-changing appearance as it works like a screen displaying the complexity of the roof structure. To smooth the edge from the shadow zone of the roof to the bright zone at the roof openings to achieve best conditions for television cameras, the membranes needed to be as translucent as possible. Therefore, a combination of transparent ETFE film and highly translucent PTFE fabric were used.