Clay’s fired surface can crack or chip under concentrated pressure, so we always recommend soft washing over pressure washing on clay roofs. Soft washing uses a low-pressure application of a biocide treatment to kill moss, lichen, and algae at the root, followed by a gentle rinse. Because the biocide continues working after application, most of the dead growth naturally washes away in the following rainfall rather than being blasted off immediately. Visit Now:-https://arcleaning-sealing.co.uk/clay-vs-concrete-roof-tiles-do-they-need-different-cleaning-methods/