How to Paint Limestone | Hunker
Step 1. Wash the limestone surface with either soapy water or a specialist trisodium phosphatebased cleaner (TSP), which helps to remove dirt and grease. Wear protective gloves if you use TSP. Scrub the surface with a stiff brush to remove any loose materials or dust. Start at the top of the wall and work your way down. Leave the surface to dry.