AC leak causing black mold on wall: fix cost in Dubai?« Back to Previous Page

That black speckled pattern is a classic sign of microbial growth, likely a combination of moulds and bacteria, feeding on the constant moisture from your AC condensate leak. The high humidity we experience in Dubai for much of the year creates an ideal environment for this.

Addressing this yourself with bleach is a temporary surface fix at best. Bleach does not penetrate porous materials like drywall or skirting boards to kill the root structure, and the moisture source remains. You'll clean the visible stain only for it to return. The primary action is to stop the leak. This could be an obstructed condensate drain line, a faulty drain pan, or incorrect unit levelling—issues a qualified HVAC technician should diagnose and repair.

For a small, contained area, a handyman might handle the physical repair of the skirting board and repainting for a few hundred dirhams. However, if the moisture has seeped into the wall cavity, the drywall itself may need cutting out and replacement, which increases the scope and cost significantly. A proper mould remediation for a case like this, which includes fixing the source, containing the area, removing contaminated materials, and HEPA vacuuming, will be a more comprehensive service.

Given the potential for hidden damage and to ensure the species is identified, a professional inspection is wise. They can provide a precise scope of work and quote. For any remediation, always request a post-clearance verification test to confirm the spore count in the air has returned to normal indoor levels—this is the only way to confirm the job was done correctly.