Black spots in damp closet: DIY or call professional?« Back to Previous Page

The black spots on your external wall are likely mold, a common issue here due to our high humidity and temperature differences that cause condensation. Before doing anything, determine the moisture source—it's often a small leak in the external wall sealant or a thermal bridge causing cold spots where moisture condenses.

For a small area (under 1 square meter), you can attempt DIY. Use a diluted detergent solution, not bleach or vinegar, as these can damage paint and only surface-clean without addressing the moisture source. Bleach fumes are also hazardous in enclosed spaces. After cleaning, the area must be kept completely dry with a dehumidifier or constant AC airflow to prevent immediate regrowth.

However, given the location on an external wall and the persistent damp feeling, a professional inspection is strongly recommended. In Dubai's climate, this often indicates a building envelope issue that DIY cannot fix. Professionals use moisture meters and thermal imaging to find the exact entry point of moisture. They can also perform air or surface sampling to identify the mold species, which is important as some types common here can cause more significant health effects.

The remediation process itself involves containment, HEPA filtration, and antimicrobial treatment to prevent spores from spreading to other areas of your home, like your winter clothes. For a confirmed moisture intrusion issue from an external wall, the long-term solution will involve repairing the building's sealant or insulation, which is beyond a cleaning product's scope.