The roof protecting spectators against sunshine has been designed to hang in two arched steel beams spanning across the entire arena ground.

The curved beams, each 300 metres long, are designed as steel tubes with a diameter ranging from 300 centimetres to 350 centimetres and a wall thickness from 60 to 95 millimetres. The beams are constructed by connecting 3 metres long tube elements.

The Italian construction company Cimolai, an expert in the field of steel constructions, prefabricate tube sections at their fabrication works in Italy. These are then shipped to Greece and joined together on site in Athens.

Cimolai has selected P-scan 4, an ultrasonic inspection system developed by FORCE Technology,  for the automated ultrasonic inspection of welding done in Italy and to be done onsite when the curved steel beams are raised in Athens.