3 ms·Were these buildings then cleaned, or do the buildings "recover" through natural processes (rain etc)?by jordn 8y agoWere these buildings then cleaned, or do the buildings "recover" through natural processes (rain etc)?berkut 8y agoI think cleaned by sand-blasting... Several cities in the UK (Bath, Coventry in particular) I remember as a child in the 80s suddenly had a lot of buildings that were no longer black.toyg 8y agoThey need to be cleaned. The elements actually make things worse.