Unsealed slate tile flooring can be a beautiful floor choice, but it also can become damaged and show wear and tear. Stains can seep down into the pores. Since unsealed slate tile can chip or stain easily, it's important that you clean it using proper care and cleaning products.
Sweep the floor to remove crumbs or small pieces of debris that could scrape or chip the floor when you begin mopping.
Use a dust mop after you use a regular broom. This will trap any finer dust particles, which also could cause small scratches under the weight of a wet mop.
Prepare a cleaning solution of warm water mixed with a small amount of gentle laundry detergent. Use about 1 tablespoon of detergent per gallon of water.
Mop the floor with the solution using a standard wet mop or rag mop. Wring out the mop thoroughly after each rinsing, and rinse it often.
Mop the floor again using just water if there is any noticeable soap residue left on the tiles.
Spot treat any stains in the slate with a mixture of abrasive cleaning powder and water. Mix the powder and water into a thick paste, apply it to the stain and let it sit for two days. Remove the dried paste with a plastic spatula. Test this method on a small, inconspicuous area of the floor first to be sure it won't alter the color of the tile.