AC smell and black spots: DIY clean or call pro?« Back to Previous Page

The damp smell and black spots are classic signs of a mould issue, very common here due to our high humidity and constant AC use. The wall-ceiling corner is a prime spot for condensation to form when cool air from the AC meets the warm room air, creating the damp environment mould needs.

Using bleach is not recommended. It may remove the visible stain on non-porous surfaces but often fails to kill the mould roots deep within drywall or plaster. More importantly, it does not address the underlying moisture problem causing the growth.

For a small area (less than one square meter), you can carefully clean it yourself with a dedicated mould remover or a solution of distilled white vinegar and water. Always wear an N95 mask and gloves to avoid inhaling spores. However, scrubbing often disturbs the spores, spreading them to other areas.

Given the location (ceiling/wall junction) and the accompanying AC smell, this strongly suggests a wider issue. The AC unit itself is likely a source of moisture and mould, spreading spores throughout the room. Simply cleaning the wall is a temporary fix.

A professional inspection is advised to identify the true moisture source—whether it's condensation, a small leak, or a problem within the AC system itself. They can also assess the extent of the growth, which may be more widespread inside the wall cavity. In Dubai, remediation should follow standards like the IICRC S520 to ensure it's properly contained and removed. A reputable provider will typically use lab analysis to identify the mould type and verify the cleanup's effectiveness with post-remediation testing.