How to Clean Mold/Mildew from Sealed Natural Stone Shower


Amy asked: How do I clean mold and mildew from a sealed, natural stone shower? We have remodeled and used natural stone. The stone is sealed, but since it is natural, it has “artifacts” that are pits/holds in the stone. This collects mold and mildew. Most commercial products say “not for natural stone.” I use a hard brush, and I try to squeegee the shower walls, but still, there is some mold on the stone and grout.

Natural stone is attractive, durable and relatively easy to care for, especially if it has been properly sealed. In the case of sealed natural stone in the shower, removal of mold and mildew is simply a matter of getting the right product for the job. Here’s a no-scrub method that makes cleaning almost effortless!

You Will Need:

Steps to Remove the Mold and Mildew:

  1. Before you begin, be sure to protect nearby non-masonry surfaces from overspray. You should also spot test the product in a hidden area before first use.
  2. Spray the mildew remover onto the mold and mildew areas, holding the bottle 2-4 inches from the surface.
  3. Allow the spray to sit on the stains for 5 minutes.
  4. Rinse well with cool water.
  5. If needed, wait 30 minutes and repeat.

Additional Tips and Advice

  • Another option is to use a degreaser diluted with hot water. Combine 10 parts water to 1 part degreaser. Use a scrub brush with plastic bristles to apply the mixture to the stains and scrub them away. Make sure the product you use is safe for stone and spot test before you begin.
  • Although it’s often suggested as a way to eradicate mold and mildew, bleach is not a good option for stone. Use of bleach may result in fading or discoloration of stone, grout and/or nearby surfaces.


  1. Whitney says:

    I have natural stone in my shower and the bathroom and limited ventilation. I’m constantly trying to clean the mold/mildew from the shower with no great solution. I knew I wasn’t supposed to, but used a mold/mildew remover (Tilex) with bleach because I was sick of feeling unclean in my sh/ower, and now I have stone that feels unsealed and stained. Is there an easy fix?

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