Hi I have a garage with a concrete roof which is also my patio . It is tiled and has a sandbed below the tiles I think 30 to 40 mm thick . Every time it rains my driveway is wet up to a week after the rain water seeps out from the front edge of the slab and in the corner black mould keeps appearing? I have to change the gyprock every 6 month in the corner . I have injected that area and it still comes back I have sealed the tiles on top of the slab but still it gets black mould and leaks fron the front edge! Please can someone help me?

Would putting something to divert the water from rolling down around it work? They say the best thing for cleaning black mold is vinegar.