Oh the Mold…the Mold is Back, with a Vengeance!!

August 15, 2013 Off By Torin Dixon
Cleaning Black Mold from Slate in Shower

Mold on Slate

It must be the Summer heat and Humidity…we are getting many calls on how to Remove Mold from Stone Showers

by Torin Dixon

Mold needs Moisture and a Food Source (more info) to grow. Naturally, a wet shower is a prime breeding ground for Mold Spores.

Its not very pleasant to think about, but when we shower, skin cells and other organic elements are rinsed off our bodies. Generally, we think that all this gunk is going down the drain, but on a microscopic level, many molecules of organic matter are sticking to the pores of natural stone, grout and is a virtual mold factory in the making.

During the moist and humid summer months, in some areas, it can be a virtual nightmare to control mold. I have received several calls this month from people needing help. Below is a comprehensive program to remove mold, AND help to prevent it from reoccurring:


  1. Use rubber gloves and safety glasses. Ventilate room
  2. Spray R60 liberally over entire affected area.
  3. Allow to penetrate for 15 minutes (do not allow to dry on surface)
  4. Scrub area with stiff scrub brush and Hot water
  5. Rinse thoroughly
  6. Repeat steps 2-5

Wash/Neutralize stone with HMK R55 Intensive Cleaner

    1. Mix a solution 1-part R55 to 3-parts warm water
    2. Scrub area with stiff scrub brush, allow to dwell on surface for 15 minutes.
    3. Rinse with hot water, allow to drain for 5 minutes
    4. Repeat

For severely affected areas follow these steps:

  • Follow instructions above Three Times
  • Use a space heater with fan, on High Heat with fan directed on worse area. This will bake/cook any remaining mold spores


Protecting your natural stone surfaces with a Professional Grade stone Impregnating Sealer will go a long way to help prevent mold from returning. I recommend using HMK S34 Silicone Impregnator. S34 will penetrate the pores of stone and grout, leaving a protective layer to prevent stains and mold from forming.


Regular maintenance using a quality product that is designed for maintaining Natural Stone surfaces will help keep the mold spores from taking hold again. For weekly cleaning use HMK P24 Liquid Stone Soap, 1/4 cup per 2 gallons warm water and scrub tile or stone shower and do not rinse. P24 Stone Soap has cleaning agents and conditioners to keep your stone clean and supports your sealer/impregnator.


If you have a stubborn stone care issue, please email Torin Dixon at torin@stonecareonline.com or call Toll Free 800-380-6881