Tips & Warnings. 1  If you are cleaning an indoor concrete slab, wet it down thoroughly with a mop and plain water, then scrub with scrub brush. 2  Mix up an all-purpose cleaning solution, scrub the concrete, then rinse with a mop and clean water.
How to Repair Potholes in Dirt and Gravel Driveways - How to . Most potholes in dirt or gravel driveways are caused by water trapped below the surface, so be sure to maintain or improve the quality of underground drainage.
Natural sinkholes â as opposed to manmade tunnel or cave collapses â occur when acidic rainwater seeps down through surface soil and sediment, eventually reaching a soluble bedrock such as sandstone, chalk, salt or gypsum, or (most commonly) a carbonate rock such as limestone beneath.