How do we clean white spots from bird droppings on colored concrete?
Q. How do we clean white spots from bird droppings on colored concrete? We have a church under construction with tiles on the floor. Windows hadn't been put in yet, and birds came in. The tiles are left stained white from the droppings. There were owls, as well, for some time. We were wondering if you have a tip for us about how we can clean the floor. The material is dark purple colored, polished cement tiles. We have tried cleaning it. Of course, the rough poo came off, but there is a white stain left, which doesn't go away. We used Handy Andy, Sunlight Soap, mold cleaner, and vinegar.