Removing Mildew from Tumbled Marble

• 1). Inspect your tumbled marble surfaces for water stains. Through wear and tear, especially in high-traffic areas, sealed surfaces can become etched. In showers, steam can seep into any cracks in the grout of sealant and will be absorbed into the porous stone. If you see mildew, check the grout for cracks or wetness; inspect the stone for signs of wetness.
  
  
• 2). Wash the mildew-stained surface with a pH-neutral cleaner. As a preventative measure, tumbled marble surfaces should be cleaned with a soap-less cleaner, rinsed well with cool water and dried with a soft towel. Many stone tile distributors carry their own line of cleaners and sealants or will recommend a product line. Follow directions on the cleaner. If the mildew stains don't disappear, consider a poultice.
  
  
• 3). Poultice powders are designed to reabsorb a wide range of stains from porous stone surfaces, including tumbled marble. Depending upon the stain (oil, ink, food or mildew), stone tile distributors will typically recommend a specific poultice. For example, Stone Care International markets MPP poultice powder specifically for mildew and mold. When made into a paste and spread on the stone, the poultice acts to reabsorb stains from the porous stone.
  
  
• 4). Follow directions on the poultice product. Spread the poultice mixture over the entire stone surface. Because colors will change after cleaning with the poultice, you want to make sure that surfaces are cleaned all at once. Use a soft-bristle brush to work the poultice into grout and grout joints. Maximize the absorption potential of the poultice by allowing it to rest on the stone surface.
  
  
• 5). Cover the poultice with a plastic sheet. Tape the sheet in place and allow it to sit on the tumbled marble surface for the amount of time recommended on the product. Rinse well with cool water. Make sure all product is rinsed away, especially in grooves and craters of the stone and grout. If mildew stains remain after the poultice, you might need to have the surfaces professionally honed and sealed.
  
  
• 6). Apply a sealant. Once the mildew stains have been removed, you need to reapply the best sealant your budget can afford. Again, the stone tile distributors who installed your tumbled marble will recommend one of their own sealants or a preferred line.