The intervention area, concerned by the restoration project, is located in the compound of the intercontinental Airport “Leonardo da Vinci” in Fiumicino, specifically in Terminal 3 building. The roofing sections of Eastern and Western Docks and of the Altitude 10 Air Side Terrace were in a significant state of decay, also because of some prior non-coordinated maintenance works, which had increased the complexity of the surface over the years. The project area was characterized by a plain roofing with a waterproof sheath topped by a monocomponent resin. A series of surveys and analysis was carried out to accurately assess the state of degradation and define the best approach for requalification. By means of such information, it was thus possible to identify the preexisting layers of the roofing, so as to better understand any previous maintenance activity, which represented one of the most demanding aspects of the intervention. Ultimately, a further critical aspect was the need to act on a surface with military functions and housing several mechanical plants, without interfering with the regular performance of the services.