The black discoloration strongly suggests the presence of Stachybotrys chartarum or another toxigenic species, which releases mycotoxins into the air. Simply applying bleach is a dangerous and ineffective solution. Bleach only removes surface discoloration on non-porous materials; it does not kill the root structure (hyphae) of the mold growing deep within your drywall and insulation. Furthermore, the chlorine in bleach can react with high indoor humidity, common in Dubai, releasing harmful gases. Disturbing the colony without proper containment and air scrubbing will aerosolize these spores, significantly increasing the health risk to your family through inhalation.

The root cause is the AC leak, which is creating a constant moisture source—the primary requirement for mold growth. A professional remediation process is multi-stage: first, identifying and repairing the AC leak to stop the moisture intrusion. Then, implementing strict engineering controls like physical containment and negative air pressure to prevent cross-contamination. The affected building materials must be safely removed and disposed of. Finally, the area is thoroughly cleaned, sanitized with EPA-approved, non-bleach biocides, and the air is scrubbed with HEPA filtration.

For a job of this nature in the Jumeirah area, costs are highly dependent on the extent of the damage behind the wall. A reasonable estimate for a professional remediation of this scope, including moisture mapping, containment, and removal, would typically range from AED 2,500 to AED 6,000.

Given the health risks and structural implications, a professional inspection is critical. I strongly recommend you contact our team at Saniservice for a comprehensive assessment. Our certified experts can provide a precise diagnosis and a transparent, fixed-price quote. Call us at 800-MOLDS (800-66537) or email hello@saniservice.com to schedule an inspection.