Wear gloves, eye protection, and an N95 or higher respirator
Keep the area ventilated; open windows if possible
Seal off the area with plastic sheeting if the mold is more than a small patch
Do not dry-scrub or vacuum with a household vacuum
For small, non-porous areas (tiles, sealed surfaces): scrub with detergent and water, then apply a mold-killing cleaner
Use one of these options for non-porous surfaces:
1 cup bleach per 1 gallon of water (do not mix with other cleaners)
Use a commercial mold remover labeled for the surface type
Let the cleaner sit for the time on the product label
Scrub thoroughly, then rinse with clean water
Dry completely using fans/dehumidifiers
For porous materials (drywall, ceiling tiles, carpet, insulation): remove and discard if moldy
Do not attempt to “clean” mold inside porous materials if it has penetrated
Clean remaining non-porous items and surfaces after removal
Bag contaminated materials in sealed plastic bags and dispose according to local rules
Fix the moisture source (leaks, condensation, humidity) before cleanup
Keep indoor humidity below 50% with a dehumidifier or HVAC adjustments
If the mold covers a large area (about 10 sq ft / 1 sq m or more) or returns quickly, hire a licensed mold remediation professional
Call a professional immediately if there’s extensive damage, strong odor, or mold in HVAC ducts
Seek medical advice if you have symptoms (wheezing, coughing, asthma flare-ups, allergic reactions) after exposure