Often used outdoors for steps and paving slabs, limestone is durable but at the same time requires special care. Over time, rain and foot traffic will wear and etch limestone to give it a beautiful patina. Abrasive and acidic cleaners will degrade the surface of your limestone prematurely. The best advice for cleaning limestone steps is to use only non-abrasive, pH-neutral cleaners to scrub away the grime.
Dilute the pH-neutral commercial cleaner with water according to the manufacturer's instructions. Any stone cleaner or all-purpose cleaner will do. If using washing-up liquid, mix 30 ml (2 tbsp) per 4.5 litres (1 gallon) of water. Mix well.
Dip a scrubbing brush in the solution and use it to scrub any visible muck off the steps.
Rinse all of the soap residue off of the steps with plain water.
Read the instructions on commercial cleaners carefully. There may be different dilution ratios for limestone.
Sweep the limestone steps regularly to minimise the build-up of dirt.