Mold spores are all around us, and all it takes for them to activate is some moisture and warmth. Suddenly, a mold colony begins to grow. The growth can happen anywhere the conditions are optimal on any surface from wood to tile to sheetrock walls. The mold you discover on your walls can be black, green, brown, or white. If the colony is large, it is important to determine which type of mold growth you have before tackling the cleaning job to determine the overall health effects to your and your family:
- Allergenic molds can be removed safely by using disinfecting products
- Pathogenic molds can be removed with disinfectants: however, large colonies require professional treatment
- Toxic molds require professional treatment and disposal of all affected materials
Small colonies of mold, even toxic molds, can be removed with some basic disinfecting supplies you probably have on hand by following safety procedures. However, if the mold growth is extensive, it is a good idea for a professional mold removal company to test and remove the mold. The U.S. Department of Environmental Protection recommends professional removal of mold colonies that cover more than 10 square feet (roughly a three-foot by three-foot patch). Local public health departments offer advice on mold testing and refer you to a mold remediation company.
How Often to Clean Mold off Walls
Mold should be removed as quickly as possible once it is discovered. Even if you don't see mold growth, there are signs of a potential mold problem that can help you prevent the colony from growing out of control:
- You detect a musty smell in your home. The odor signals a mold problem that needs to be addressed.
- You have neglected a leaky faucet or roof.
- A wall that feels soft or damp to the touch may indicate that there is interior mold growth that will soon appear on the surface.
- There is moisture accumulation that takes a long time to evaporate from walls due to poor ventilation in the house.
Equipment / Tools
- Protective gloves
- Protective eyewear
- Protective facemask
- Step ladder
- Plastic bucket
- Microfiber cloth
- Measuring cups
- Spray bottle
- Soft-bristled brush
- Chlorine bleach
- Dishwashing liquid
- Hydrogen peroxide
- Distilled white vinegar
Mix the Mold Cleaning Solution
In a plastic bucket, mix one-part dishwashing liquid, 10 parts bleach, and 20 parts water. To clean a small area of mold, mix a solution of one tablespoon dishwashing liquid, 1/2 cup chlorine bleach, and one cup of warm water in a spray bottle. The dishwashing liquid helps the solution cling to the wall longer to kill the mold spores.
When removing mold, it is best to wear old clothes that you don't mind being splattered with bleach and that can be washed in hot water to remove any mold spores that might scatter to the surface. Put on a face mask (N-95 is recommended), protective eyewear, and gloves.
Increase the Ventilation in the Room
To improve ventilation while you are cleaning, open windows or add a circulating fan. If you are working in a bathroom, turn on the bathroom ventilation fan and use the exhaust fan in the kitchen.
Apply the Cleaning Solution
The cleaning solution can be applied with a spray bottle or a sponge. It's best to clean mold starting at the bottom and working your way up. This keeps the spores from spreading and the stain from streaking on your wall. The surface of the wall should be fully wet but not oversaturated to prevent damage to the drywall. If the mold is near the ceiling, always use a sturdy stepladder or apply the solution with a clean sponge mop.
Air-Dry the Wall
Do not wipe away the cleaning solution. Allow the wall to air-dry.
Check for Remaining Stains
Once the wall is completely dry, check the area for any dark stains. If they remain, repeat the steps with a fresh chlorine bleach cleaning solution.
Tips to Prevent Mold Growth on Walls
- Repair leaky plumbing and roofs promptly.
- Improve air circulation in the home and reduce moisture with a dehumidifier.
- Install a moisture barrier in unfinished basements and crawl spaces.
- Clean mold and mildew-prone rooms weekly (bathrooms, laundry rooms, kitchens).
- Mold Allergy. Asthma and Allergy Foundation of America.
- Kuhn DM, Ghannoum MA. Indoor mold, toxigenic fungi, and stachybotrys chartarum : infectious disease perspective. Clin Microbiol Rev. 2003;16(1):144-172. doi:10.1128/CMR.16.1.144-172.2003
- Mold Cleanup in Your Home. U.S. Environmental Protection Agency.