Ceresit CT 84 is a polyurethane adhesive used for fi xing Expanded Polystyrene & MW boards in Ceresit Ceretherm Systems for thermal insulation of external building walls (ETICS). CT 84 can be used for fi xing foamed polystyrene boards & MW in providing thermal insulation for newly erected buildings and those subjected to renovation of thermal insulation. Approximately 2 hours after the application, the insulation boards may be smoothed and anchored, then the reinforced layer may be applied using the Ceresit CT 80, CT 85, CT 87, CT 190 or ZU.