Mold On Natural Stone Patio And How To Remove It

Mold is as natural as natural stone to start with!  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.  Dirt, natural debris, and ambient moisture are the key breeding factors for mold to grow on just about any 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.  Here are four tips to easily get rid of mold on travertine, limestone, marble and actually any other natural stone installed at a patio or indoors.

1. Cleaning Often

The spores will easily find the necessary nutrients for their development.  The problem with letting dirt accumulate on top of outdoor natural-stone pavers, 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 clean water, in most cases, as simple as power washing the patio with clean water.  Also a cleaner specifically formulated for natural stone care, such as our FILA Cleaners will do a great job on cleaning all natural stone surfaces.

2. Sealing Properly

Some of us mistakenly think stone installed outdoors won’t require sealing because of its rough finish.  However, natural stone installed outdoors also needs to be properly sealed to prevent mold.  Mildew can still develop into surface mold on top of sealed stone, but it can be easily wiped away.  We have a full line of top of the line sealers under FILA brand.  

3. Scrub with Bleach and Water

Common household cleaners shouldn’t be used on natural stone surfaces, but household bleach is an exception when you need to scrub away mold as a practical and effective solution.  Prepare a 50/50 solution of bleach and clean 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 clean water and using natural stone cleaner and sealant.

4. Keep the Stone Dry

In addition to keeping the seal on natural stone fresh and strong, the surfaces should be kept dry as much as possible, especially the tiles or slabs used indoors.  

Whether the stone is used outdoors or indoors, natural stone care is relatively simple if we all know how to do it properly and keep up on the maintenance. 

FILA products offer complete care and ongoing maintenance for natural stone surfaces.

Be sure to check with your local QDI Surfaces office or sales representative for more information and pricing.

Leave a Reply