Sandstone is a natural rock formation, quarried and cut into smaller pieces. Homeowners and masons choose sandstone for patios, walkways, chimneys or foundations because it is durable. Sandstone is most recognizable as a New England dry wall, which is pieces of stone fit together and built without mortar. Depending on the region, sandstone is available in a wide range of colors including black, brown, red or gray. Each piece of sandstone will vary in color, adding interest to the structure.
Mix equal parts chlorine bleach and water in a spray bottle.
Spray the mixture onto the mold generously and allow the bleach to remain on the surface for 10 to 15 minutes. Spray the mold a second time.
Scrub the mold with a stiff-bristled scrub brush. Rinse the area thoroughly with plain water. Repeat if necessary.
Spray a commercially prepared antimicrobial spray onto the moldy surface. If the area is large or there are areas that are not reachable, rent a fogger. To use a fogger, place it in the area that has mold growth, add the antimicrobial agent and release the fogger. The mist will settle onto the mold and kill it.
Allow the spray to remain on the surface and dry completely. The spray will form an airtight protective coating and suffocate the mold.
Soak a rag with the antimicrobial spray and scrub the surface to remove mold.