Flat roofs, require to be maintained regularly. There was now only one city prior to Kyiv, Cherkasy; I would consider my lunch there.
First of all you require to make sure that the roof is drinking water evidence and it stays dry. https://njspmaca.in/2024/06/26/best-material-choices-for-flat-roofs-by-dimentional-roofing-and-diagnostics/