Black spots on damp closet wall: DIY or call pro?« Back to Previous Page

The dampness and black spots on your external wall are a classic Dubai issue, caused by the constant high humidity and temperature differential between your air-conditioned room and the hot exterior. This creates condensation inside the wall, providing the perfect environment for mould.

For a small area (under one square meter), you can attempt a DIY approach. Wear an N95 mask and gloves. Mix a solution of one part white vinegar to four parts water and scrub the area. Do not use bleach, as it only removes the colour and can push spores deeper into porous surfaces like drywall. After cleaning, the wall must be completely dried. A dehumidifier or fan directed at the spot for 24-48 hours is essential.

However, the dampness feeling indicates an ongoing moisture problem you cannot scrub away. The mould is likely growing within the wall cavity itself. In this case, DIY is a temporary fix. You need a professional inspection to identify the moisture source—it could be insufficient insulation, a tiny crack in the building envelope, or internal condensation. They use moisture meters and thermal imaging to find the root cause. If the drywall is soft or crumbling, it requires removal and replacement by a remediation team to prevent structural damage and ensure the mould is fully addressed.