How to treat black mold from AC leak in wall?« Back to Previous Page

The leak has been fixed, which is the critical first step, but the mold you see is likely just the surface indication. Given Dubai's high humidity and the porous nature of building materials, moisture from an AC leak can wick up into drywall and insulation, creating a hidden problem.

For a small, surface-level patch, you can carefully treat it yourself. Wear an N95 mask and gloves. Mix a solution of one part white vinegar to three parts water or a diluted detergent and scrub the affected area. Avoid bleach, as it only removes surface discoloration and does not kill the root structure. Dry the area thoroughly immediately after cleaning using fans and a dehumidifier to prevent immediate regrowth.

However, if the mold has reappeared after cleaning, if the patch is larger than roughly one square foot, or if there is any lingering musty odor, the mold has almost certainly penetrated the wall cavity. In these cases, self-treatment is not effective and can disturb spores, spreading them further. The only way to verify the extent is through a professional inspection, often involving a moisture meter and sometimes a borescope to view inside the wall.

The remediation process for a contaminated wall typically involves controlled removal of the affected drywall and insulation to prevent cross-contamination, followed by HEPA vacuuming and antimicrobial treatment of the cavity. Given the year-round reliance on AC here, ensuring the wall is completely dry and free of mold is essential to prevent it from returning and impacting your indoor air quality.