They have started cleaning the surfaces with the help of the growth remover SIPROUNIQAUT. To preserve the roofs, the surface must always be made free of grease and dirt. This has been done with UNICLEAN LOW FOAMING. In addition, the surfaces have been dried and degreased extra with ISOPROPANOL. When using NITOCOAT, the surface can be dried with ISOPROPANOL after cleaning and rinsing with tap water.
Finally, a layer of NITOCOAT has been applied to keep the surfaces clean and to guarantee the color. Afterwards, the roofs looked like new again.