As a pervasive natural organism, mold often manages to form colonies within grouting, thus turning the area dark green before becoming completely black and hard to remove. Mold on grout lines is a biological stain that requires killing the organism. Homeowners who use organic soap to remove mold may actually be feeding the spores instead of killing them, which is something bleach can certainly do.
Homeowners whose floors are covered with ceramic tiles or laminate materials often use bleach to remove mold. For natural-stone surfaces, bleach cannot be recommended for various reasons. There’s only one exception to this rule, and it will be mentioned below, but there are better options for marble, slate, granite, and other types of natural stone. If you’re wondering how to clean grout and whether or not bleach is safe to use, read on.
Bleach Can Stain Natural Stone
On the pH scale of acidity and alkalinity, bleach scores somewhere between 12 and 13. Any substance with a pH level higher than 7 is considered a base chemical, which means it has properties that can initially cause staining and later etching. Once a chemical reaction has progressed to etching, the molecular structure of natural stone will change, damaging the surface.
Keep These Other Cleaners Away from Natural Stone
Bleach, ammonia, and vinegar are part of a trifecta that can weaken the protective seal of natural stone and damage the surface. Their very high or very low pH levels make them abrasive and caustic. Moreover, they can often be found in common household cleaners, which is why you should only use pH-balanced products such as Granite Gold Grout Cleaner®.
Here’s a quick yet informative video explaining how to use Granite Gold Grout Cleaner®:
Granite Gold Grout Cleaner® Versus Bleach
Bleach won’t damage the grouting material. The problem is using it so close to natural-stone tiles. When you’re faced with moldy or extremely dirty grout lines, your best bet is to use a stone-safe grout cleaner such as Granite Gold Grout Cleaner®, a product that’s not only pH-balanced but also comes with a special grout brush that will agitate dirt and grime and won’t scratch natural stone. Granite Gold Grout Cleaner® is especially recommended for homeowners who have natural-stone showers.
The Only Time Bleach Can Be Used on Natural Stone
If the tiles have a fresh seal, Granite Gold Daily Cleaner® may be enough to get rid of mold spots. Very stubborn mold colonies, the kind that can sometimes form in natural-stone shower stalls or tub surrounds, will likely require Granite Gold Grout Cleaner®. If this doesn’t work, you can use a solution of equal parts bleach and water to scrub the grout lines, then let it sit for 15 minutes before rinsing with water.
If you have any additional questions about cleaning the grout between the natural stone in your home (as well as the stone itself), reach out to the Stone Care Experts at Granite Gold® today. Call us at 1-800-475-STONE (7866), and use our handy Store Locator to find our products at a store near you.
Lenny Sciarrino (aka Lenny S) and Lenny Pellegrino (aka Lenny P) grew up in the family business and are co-founders of Granite Gold®.