Hope someone can help, havent cleaned the patio Indian Sandstone paving in the back garden in a while so tried to start today with no great visible improvement, I used a cleaning product for paving areas and alot of scrubbing with not great reuslts. My problem is small groups of small black spots that seem to really discolour and are taking over the paving stones I think they might be lichens theres no flower on htem though just like kind of like ink spots they are more like stain spots on the sandstone slabs, Was wondering if there is another product I could use to get rid of them and clean up the paved area or would a power washer do the trick. Im sick of rubbing and scrubbing and getting no where. Those black spots or stains are hard to shift.
Any help on these would be greatly appreciated