Black grout and damp smell: professional cost and DIY fix?« Back to Previous Page

The grout between the tiles in my master bathroom at our villa in Al Barsha has been turning black for a while now. It’s spread behind the toilet and under the sink cabinet, and the damp smell is really strong no matter how much I clean. I’m worried it’s gotten into the walls and I have no idea if this is a simple fix or a major job. What’s the realistic cost range to get this professionally treated by a good company here, and is it absolutely necessary to hire someone or can I tackle it myself with the right products?
Posted by Xiao Wu
Asked on May 6, 2026 6:00 am
Black grout and a persistent damp smell in a Dubai villa suggest active mould growth, likely due to the high humidity and condensation from showers and air conditioning. This is a common issue here. The spread behind fixtures indicates it's more than surface-level; the mould has probably penetrated the porous grout and may be growing on the wall substrate behind the tiles.

For a minor, surface-only patch, a DIY approach with a dedicated mould-removing product and rigorous scrubbing can work. However, given the smell and spread you describe, a DIY fix will likely only provide a temporary solution. The root cause is persistent moisture, and the mould is almost certainly deeper than you can reach. Improper cleaning can aerosolize spores and spread the problem.

A professional assessment is necessary to determine the extent of the damage behind the tiles. The cost for professional remediation is not fixed; it depends entirely on the square footage affected and the depth of the infestation. Treating a small, contained area is a straightforward job, while addressing mould that has spread into the wall cavity behind the tiles is a more involved project that requires containment, removal of affected materials, and addressing the moisture source.

The critical first step is a proper diagnosis to understand the scope. A reputable company will use moisture meters and possibly borescope cameras to inspect behind walls without unnecessary demolition. They should provide a clear scope of work and cost estimate based on that assessment, not a generic package price. Always request that they identify and rectify the source of the moisture, as simply cleaning without doing this guarantees the mould will return.
Posted by Sani Admin
Answered on May 7, 2026 8:46 am