Mildew is a slimy fungus that grows in high humidity and warm temperatures. Unfortunately, when mildew grows on concrete, it looks like brown-green slime, plus the mildew can make the concrete surface dangerously slippery. Most often mildew grows in the summer and is difficult to prevent, but here's one method of cleaning mildew from concrete floors.
Mix in a plastic bucket a solution of liquid chlorine bleach and warm water. Use 1/2 to 1 qt. of bleach to 1 gallon of water.
Scrub the concrete with a hard-bristled brush.
Rinse off the mildew with a hose and then dry the area.
Repeat Step 2 until the mildew is gone.
Things You Will Need
- Chlorine bleach Warm water Bucket Power washer
- Rent or use a power washer if you are cleaning large parts of a concrete path or walkway. Wear work clothes that wouldn't mind being stained or ruined by bleach.
- Using bleach other than a chlorine bleach can be toxic to the environment if used outside or near live plants or fresh water.