Black grout in bathroom: DIY or professional in Dubai?« Back to Previous Page

Black grout in a Dubai bathroom is almost certainly mould thriving on the constant humidity from showers and our climate. Bleach only bleaches the surface and doesn't kill the root structure, which is why it returns so quickly.

For a small, surface-level issue, a high-quality mould-specific cleaner from a hardware store can be effective, but it must penetrate the porous grout. Scrubbing alone is insufficient. However, given your description of it spreading and the persistent humidity, the mould has likely penetrated deep into the grout and may be behind the tiles. This is a common issue here where vapour can get trapped behind walls.

A professional assessment is recommended to determine the extent. They use moisture meters and borescopes to check inside wall cavities. If the growth is only on the surface, a targeted antimicrobial treatment can resolve it. If it has spread behind the walls, the affected section of grout may need to be removed and resealed, or in serious cases, wall tiles might need to be taken down to address the root cause and prevent recurrence. The cost for a professional service varies significantly based on the square footage affected and whether the tiles themselves need to be addressed; you would need a diagnostic assessment for an accurate scope of work.