Does Bleach Kill Mold? How to Remove Mold Walls to Ceiling

Mold on walls and ceilings is typically caused by excess moisture from sources like leaks, high humidity, or poor ventilation. When damp conditions persist, mold spores can settle and grow on surfaces, often spreading quickly. It's important to kill mold as it can cause damage to your home and significantly impact your indoor air quality and overall health. Note: if the mold has a surface area larger than 10 square feet, call a mold remediation professional.

Does bleach kill mold?

Yes, and it works by breaking down mold cells on surfaces. Knowing the right concentration of bleach is key to making your solution effective and safe. Read on to learn the correct bleach-to-water ratio for removing mold, straight from the experts at Clorox.

What does mold on the ceiling look like?

Mold on walls and ceilings often appear as black, green, gray or brown spots or patches. It may look fuzzy, slimy, or powdery and can grow in clusters. Mold is commonly found in corners, near ceilings or around windows where moisture accumulates. Sometimes it’s accompanied by a musty odor even before it's visibly noticeable.

How long does it take bleach to kill mold?

The contact time for Clorox™ Disinfecting Bleach to kill mold on hard, nonporous surfaces is 10 minutes. It’s important to let the bleach solution sit during this time before scrubbing or rinsing. For best results, always follow up by drying the area thoroughly to prevent mold from returning. Always check the product label for specific instructions and test on a small area before use.

How much bleach is needed to kill mold?

To kill mold, mix ⅓ cup of Clorox™ Disinfecting Bleach per gallon of water. Always apply in a well-ventilated area and never mix bleach with other cleaners like ammonia or acids.

What you need to remove mold on walls and ceiling

  • bottle of Clorox Disinfecting Bleach

    Clorox™ Disinfecting Bleach

  • drop of water

    Water

  • Glass measuring cup for liquid.

    Measuring cup

  • White plastic bucket with handle and lid.

    Bucket

  • yellow kitchen dish sponge with green scrubber

    Sponge or scrub brush

  • A plain white plastic spray bottle with red nozzle against a clean white background.

    Spray bottle

  • pair of yellow rubber cleaning gloves

    Rubber gloves

  • light blue safety glasses

    Eye protection

  • Black electric fan with white background

    Fan

  • • N95 respirator or face mask

How to get rid of mold on walls & ceiling

  1. Prep area

    Open windows and ventilate the area where you are working to circulate fresh air.

    open window ventilation

  2. Pre-clean surface

    If mildew is heavy, pre-clean by wiping away as much as you can before bleaching.

    Hand pressing down on yellow sponge.

  3. Mix bleach solution

    Using your measuring cup and bucket, measure ⅓ cup Clorox™ Disinfecting Bleach per gallon of water (1500 ppm available chlorine solution).

    Hand holding translucent container pouring clear liquid.

  4. Apply solution

    Wearing gloves, apply the solution to the affected area with a sponge or brush.

    Tip

    Use a spray bottle for more convenience.

    Person cleaning floor tile grout.

  5. Wait 10 minutes

    Allow it to sit in contact with the mildew for 10 minutes. If needed, reapply the bleach and water solution to keep the surface wet.

    White mechanical kitchen timer with dial set to 2 minutes.

  6. Rinse

    Rinse the affected area with clean water.

    Hand holding a handheld showerhead with water spraying.

  7. Air dry

     Allow to air dry. You may use a fan for quicker drying time.

    Tip

    If you used a spray bottle, be sure to rinse it out.

    open window ventilation

How to prevent mold

To prevent mold, you’ll want to minimize the presence of moisture. Fixing leaks, using dehumidifiers and improving ventilation can help, especially in bathrooms and kitchens. Keep surfaces dry and clean, and use exhaust fans when cooking or showering. Regularly check for condensation or damp spots to catch mold early.

Do Clorox™ Disinfecting Wipes kill mold?

Clorox™ Disinfecting Wipes are designed to clean and disinfect hard, nonporous surfaces, but they do not kill mold. However, they can be used to prevent the growth of mildew on hard, nonporous surfaces. For mold cleanup on bleach-safe, hard, nonporous surfaces, follow the product label directions for Clorox™ Disinfecting Bleach.

Tips for how to clean mold on washable walls and ceiling with bleach

  • Not sure what bleach-to-water ratio you need? Check out our handy bleach dilution chart.
  • Use freshly mixed solutions. Bleach degrades over time when diluted.
  • Never mix bleach with vinegar, ammonia or any other cleaner; doing so can create dangerous fumes.
  • Wear gloves and ensure good ventilation during use.

Where else does bleach help with mold around the house?

Clorox™ Disinfecting Bleach can help kill and remove mold on bleach-safe, hard, nonporous surfaces throughout your home when used according to the product label. For more tips on cleaning mold and mildew in bathrooms, kitchens, basements and other areas, explore our Mold & Mildew Tips page.

Frequently Asked Questions

What causes mold on the ceiling?

Mold on the ceiling or walls is typically caused by excess moisture and poor ventilation. Common sources include roof leaks, plumbing issues, high humidity, or steam from showers and cooking. The root issue is usually a combination of dampness and lack of airflow, which creates the perfect environment for mold growth.

Is bleach or vinegar better to kill mold?

Only bleach is registered with the EPA to kill mold. Vinegar has not been proven to be effective on mold with the EPA, a nationally recognized authority on mold claims.

At what temperature does mold die?

Mold begins to die at temperatures above 140°F (60°C), but sustained heat is required to be effective.1 Simply warming an area isn’t enough—high heat must reach deep into porous materials to fully kill mold. For lasting results, combine heat with moisture control and proper cleaning.

What's the best way to remove mold from walls and ceilings?

Bleach can help kill mold on hard, nonporous surfaces like painted walls and ceilings when used as directed. Clorox™ Disinfecting Bleach can help remove mold and mildew stains while disinfecting surfaces, making it a useful option for addressing visible mold growth on appropriate surfaces. Always follow label directions and ensure proper ventilation when using bleach.

Will boiling water kill mold?

Boiling water may kill some mold on hard, nonporous surfaces, but it won't remove mold stains or reliably eliminate mold growing below the surface of porous materials. After cleaning away visible mold, disinfect bleach-safe, hard, nonporous surfaces with Clorox™ Disinfecting Bleach according to the product label.

Does bleach kill mold or just hide it?

When used according to the product label on bleach-safe, hard, nonporous surfaces, Clorox™ Disinfecting Bleach helps kill mold and remove mold stains, it doesn't hide them. Bleach is not recommended for treating mold on porous materials.

Related Articles