Black mold in closet: DIY bleach or call pro ASAP?« Back to Previous Page

That's a classic scenario for Dubai, especially on an exterior wall during humid periods. The temperature difference between the air-conditioned interior and the hot, humid exterior wall causes condensation inside the wall cavity, creating the perfect environment for mold.

Don't use bleach. It's mostly water, which feeds mold growth, and the chlorine evaporates quickly, leaving the root structure intact. It also fails on porous surfaces like drywall. For a small area (under one square meter), you can carefully clean it yourself with a dedicated fungicidal cleaner, not bleach. Wear an N95 mask and gloves during cleanup to avoid inhaling spores.

However, given the location on an exterior wall, the visible spots are likely just the tip of the iceberg. The moisture source is inside the wall, which you cannot address with surface cleaning. This is a case where a professional inspection is wise. They use moisture meters and thermal cameras to assess the extent of the problem within the wall and identify the condensation source. Remediation often requires controlled removal of affected drywall and addressing the insulation or vapour barrier to prevent recurrence. For a proper assessment, you should request an inspection that includes moisture mapping.