Urgent: Black mold under shower sealant, DIY or professional?« Back to Previous Page

Black mold under sealant is a common issue in Dubai's high humidity, especially with condensation from AC use. The urgency depends on the extent. If it's a small, localized patch (under 1 square foot) and you're not sensitive to mold, DIY is possible. For larger areas, recurring issues, or if anyone has respiratory conditions, professional assessment is recommended to prevent spread into walls.

For DIY, first identify the mold type. Surface mold (on top of sealant) can often be cleaned. Sub-surface mold (underneath, as you described) means the sealant has failed and moisture is trapped. Cleaning the surface won't solve it. You must completely remove the old silicone, treat the area, and apply new sealant. Scrape out all old sealant. Use a mold-killing solution like diluted vinegar or a dedicated fungicide from a hardware store on the exposed area. Let it dry completely—a fan can help. Apply a high-quality, mold-resistant silicone sealant. Ensure the bathroom is well-ventilated during and after to allow it to cure properly.

The musty smell indicates potential hidden growth. If the area feels soft or the grout is discolored, the moisture may have penetrated deeper. In many JVC apartments, bathrooms are internal with poor ventilation, creating a perfect environment for mold. A professional inspection uses moisture meters and borescopes to check behind tiles for concealed damage, which is a common finding. They can also perform air quality tests to see if spores have spread. Dubai Municipality guidelines hold landlords responsible for fixing leaks and structural dampness, but surface maintenance often falls to the tenant. If the problem is due to a leak from another unit or a building envelope issue, a professional report is essential for building management. For a confirmed black mold (Stachybotrys) presence, which is frequently identified in such wet scenarios, remediation should be done by a certified company to ensure containment and proper disposal.