Things You'll Need:
- Pressure washer
- Water hose
- Bucket
- Household bleach
- Powdered laundry detergent
- Trisodium phosphate
- Sponge
- Garden sprayer
-
Step 1
Shoot down the wall with a pressure washer's fan spray. Use smooth, even strokes to cover the entirety of the wall, not just the area on which you notice mold growth. This forcefully removes most of the mold spores from your wall's paint and crevices. If you do not have a pressure washer, use a garden hose with a sprayer attachment to rinse the wall as best as you can.
-
Step 2
Create a mold-killing solution. Pour a gallon of warm water into a plastic bucket. Mix in half a cup of household bleach and a fourth of a cup of standard powdered laundry detergent. Stir thoroughly. Mix in half a cup of trisodium phosphate, a cleaning agent available at many hardware stores.
-
Step 3
Sponge the solution onto the green mold growth. If the mold growth is widespread, you may wish to use a garden sprayer, such as the type used to spray herbicides or liquid fertilizers. Allow the solution to soak on the wall for 15 minutes, during which time the bleach will sterilize the surface and kill the mold.
-
Step 4
Scrub the wall with a sponge. While the mold may be dead, some staining and mold growth may still be visible. The trisodium phosphate and laundry detergent will help loosen any mold stains.
-
Step 5
Rinse the wall by shooting it down with a water hose. Let the wall dry thoroughly, which may take 24 hours or more depending on your climate.
