4 Tips for Removing Mold from a Natural-Stone Patio

It doesn’t take much for mold to develop on natural stone, especially in outdoor environments such as patios. All mold requires is moisture, dirt, and a porous surface. Ancient builders learned about mold infestations on natural stone the hard way. Italian archaeologists have determined that Tuscan stonemasons used to furiously scrub Carrara marble blocks to remove fungal colonies that ultimately turned the surface black. Even though some types of natural stone are more porous than others, mold and mildew will eventually develop if the surface isn’t treated adequately. Staining is the first sign of microbial deterioration, a biochemical reaction you certainly don’t want on your natural-stone surfaces. Here are four tips you can follow to get rid of mold on granite, marble, and any other natural stone installed in your patio.

1. Clean Often

All it takes is dirt, natural debris, and ambient moisture for mold to grow on just about any surface. The spores will easily find the necessary nutrients for their development. The problem with letting dirt accumulate on top of outdoor natural-stone tiles or slabs is that it will quickly decompose, thus increasing the potential of mold buildup. The best way to get rid of mold is to not allow it to form in the first place, which requires regular cleaning with a cleaner specifically formulated for natural-stone care, such as Granite Gold Outdoor Stone Cleaner®.

2. Seal Frequently

Some homeowners erroneously think stone installed outdoors won’t require sealing because of its rough finish. However, natural stone needs to be frequently sealed to prevent the most critical mold infestations. Mildew can still develop into surface mold on top of sealed stone, but it can be easily wiped away.

3. Scrub with Bleach and Water

Common household cleaners shouldn’t be used on natural-stone surfaces, but you can make bleach an exception when you need to scrub away mold. Prepare a 50/50 solution of bleach and water to use with a soft nylon brush or pad. Allow the bleach and water solution to sit for about 15 minutes after the first scrubbing session, then finish the job by rinsing with water and using natural-stone cleaner and sealant.

4. Keep the Stone Dry

In addition to keeping the seal on your outdoor stone fresh and strong, you should also make it a point to keep the surfaces dry as much as possible. Using a dehumidifier after scrubbing away mold is highly recommended, and you should avoid drying natural stone with towels. Using a squeegee tool and allowing tiles or slabs to air dry are better options. Whether the stone is outdoors or indoors, natural-stone care is relatively simple if you know how to do it properly and keep up on your maintenance. Granite Gold® has everything you need to take care of the natural stone in your home, from granite and marble to travertine and slate, and we also offer products that are safe to use on quartz surfaces. To learn more, call one of our knowledgeable representatives at 1-800-475-STONE (7866). If you’d like to receive monthly stone care tips, please sign up for our newsletter today.