Saturate the walls with the peroxide then let it sit for up to 30 minutes.
Mold for concrete wall.
Mold on concrete walls black fungi on concrete walls mostly comes from moisture hitting and being absorbed into the wall.
Reasons to avoid bleach.
Before attempting to clean the walls first resolve the moisture issue by redirecting downspouts and swamps from the wall.
Dirty concrete surfaces like patios that don t dry out rapidly because it s in a shaded area can be the perfect area for mold to grow.
Concrete walls are not especially prone to mold and mildew which are words for the same thing.
When mold begins to grow on concrete surfaces it looks black green or a bunch of other colors.
But even an inorganic material like concrete can become mildewed when spores begin to grow on dust dirt or old paint on its surface.
It also can produce a strong earthy musty smell.
Depending on the size and severity of the mold deposits this process may take anywhere from several minutes to several hours to successfully complete.
The recommended way to clean mold off concrete is to scrub it with detergent and water.
After the mold has been scrubbed off your concrete walls allow your mold remover to sit for 15 to 20 minutes before proceeding to dry your walls.
You could also try installing an interior footing drain to keep the water from the wall.
Step 3 apply your finishing touches.
Mold growth on a concrete wall due to excess humidity.