How to remove black mold from bathtub sealant?« Back to Previous Page

Black mold on bathroom sealant is extremely common in Dubai due to the high humidity and lack of ventilation in many apartments. The condensation from showers, combined with year-round AC use creating temperature differentials, provides an ideal environment for it to grow.

For a small, surface-level patch, you can handle this yourself. Wear a mask and gloves. First, create a paste of baking soda and water or use a dedicated hydrogen peroxide-based cleaner. Scrub the affected sealant thoroughly. For persistent growth, a diluted bleach solution (one part bleach to four parts water) can be effective, but ensure the room is well-ventilated. After cleaning, the critical step is to keep the area completely dry for 24-48 hours to prevent immediate regrowth.

However, if the mold is "creeping out from behind" the sealant, it is very likely growing beneath it and has penetrated the wall substrate. In this case, DIY cleaning only addresses the visible portion. The hidden mold will continue to spread. For a case this advanced, the only permanent solution is to have the old silicone sealant professionally removed, the underlying area treated with antimicrobial solutions to address the root colonization, and then completely resealed with a high-quality mold-resistant silicone.

Given your description of the extent and the potential for hidden growth inside the wall cavity—a common issue in buildings here—a professional inspection is strongly recommended to assess the full scope. They can use moisture meters and borescopes to check the wall's condition without destructive testing.