Black shower grout: DIY cleaning or professional help needed?« Back to Previous Page

That black grout returning despite cleaning is a classic sign of a deeper mould issue, not just surface dirt. In Dubai's high humidity, bathrooms are prime locations for mould growth within the porous grout and potentially behind tiles if there's a hidden leak.

For a persistent problem in a frequently used shower, a stronger cleaner is unlikely to provide a lasting solution. You can attempt a targeted approach using a hydrogen peroxide-based solution or a dedicated grout cleaner, applying it and letting it sit for 10-15 minutes before scrubbing with a stiff brush. However, if the discoloration returns within a few weeks, the growth is subsurface.

Given your location in a villa and concern about spread, a professional assessment is advisable. They can use moisture meters to check the walls for hidden dampness—a common issue if the waterproofing membrane was compromised during construction. For extensive or recurring growth, remediation that includes removing and replacing the affected grout is often the only permanent fix. To prevent recurrence, improve ventilation by running the exhaust fan for 30 minutes after showering and consider a dehumidifier.