How to permanently stop black mold from closet condensation?« Back to Previous Page

That recurring black mould is a clear sign of persistent moisture, almost certainly from condensation due to the temperature difference between your cold AC room and the warm, humid Deira air outside the wall.

First, stop wiping it. Bleach or vinegar only removes the visible stain, not the root cause. The mould's microscopic roots are still in the wall, and moisture is reactivating them. Scrubbing can also release spores.

Your priority is controlling humidity. Ensure your AC unit is set to a consistently cool temperature, ideally between 22-24°C, to reduce the massive differential that causes condensation. Run it continuously in that room, even when out, to maintain a stable environment. A standalone dehumidifier in the room, especially during more humid months, can also help measurably reduce ambient moisture.

The issue is likely inside the wall. The closet is the coldest spot, making that external wall a prime condensation site. The most effective permanent solution is to address the building envelope. This involves a professional inspection to identify if there's insufficient insulation in that wall cavity or cracks letting humid air in. Remediation often requires cutting into the wall to install proper vapour barriers and insulation to prevent the cold surface from forming. For a definitive diagnosis of the mould type and moisture source, a professional inspection using thermal imaging and moisture meters is the most reliable path forward.