How to Clean Mildew From a Concrete Patio

Mildew is a type of fungus that thrives in damp or dark conditions. When mildew grows on your concrete patio, it can appear as green or black, foul-smelling patches. It can ruin the appearance of the patio, and even cause or irritate respiratory problems, according to the U.S. EPA. Clean your concrete patio with a homemade solution to kill the mildew, and keep it clean and as dry as possible to prevent future growth.

Step 1

Fill a bucket with 3 qts. of warm water, 1 qt. of bleach and 1/3 cup of powdered laundry detergent. Put on rubber gloves, and stir the solution with a wooden spoon until the detergent dissolves completely.

Step 2

Move any furniture, plants or items from the patio before cleaning.

Step 3

Pour the solution onto the concrete patio, concentrating on areas with mildew. Allow the solution to sit for up to 15 minutes.

Step 4

Scrub the patio with a stiff-bristled broom to remove any remaining mildew.

Step 5

Rinse the patio thoroughly with a garden hose to remove any bleach solution. Allow the concrete patio to air dry.