How to Remove Mold from Concrete, Brick, and Stone

Bleach works best on exterior home surfaces. Be sure to take proper precautions to avoid getting mold removal Syracuse bleach on any surrounding fabrics or plants.

Mix a Cleaning Solution
In a bucket, mix one cup of chlorine bleach with one gallon of water. Following the directions of the manufacturer, this can be added to a garden sprayer or power washer or can be applied by hand with an abrasive mop or brush.
Plastic bucket mixed with baking soda and distilled white vinegar
Wet Surfaces and Apply Solution
Wet the moldy surfaces with plain water using a garden hose or by hand, then apply the bleach and water solution. Allow it to sit on the surface for 15 minutes before scrubbing to remove the mold growth., and allow it to sit on the surface and work for several minutes.

Nylon-bristled broom scrubbing cleaning solution on unsealed concrete patio
Rinse and Air-Dry
After scrubbing, rinse the surfaces rinse and any surrounding areas (especially plants) that may have been inadvertently splashed with bleach. Repeat steps, if needed.

Dangerous Mold vs. Mildew
All mildew is mold, but not all molds are mildew. Mildew can discolor and slowly harm surfaces but there are much more dangerous molds that can damage the structure of your home. The most common type of mold found in homes is mildew. Mildew is a surface mold that grows in warm, damp places like your bathroom, on fabrics, and books stored in damp basements.

Mildew begins as a gray or white powdery colony. It will turn black or brown if not removed promptly and often looks like soil accumulation.

To test if the surface is covered with mildew or just dirt, dab the stain with a cotton swab dipped in household chlorine bleach. If the stain lightens or disappears after two or three minutes, it’s mildew. If not, it’s probably just dirt.

Discovering Mold From Smell
If you detect a musty smell anywhere in your home, then you have a high concentration of mold. It can be coming from a hamper filled with damp towels, from a damp crawlspace under your home, or from carpets that have mold growing in the padding. If you smell that odor, it’s time to take action to get rid of the problem.