Black Mould in the Bathroom or AC: Causes and How to Remove It
Black mould in a bathroom or around AC vents is caused by moisture that never gets the chance to dry: steam from showers in windowless bathrooms, and condensation inside AC units, ducts and grilles. Small spots on tiles and grout can be cleaned at home. Mould that keeps coming back, has soaked into silicone, or is blowing out of the AC needs a deep clean, and the moisture problem behind it fixed.
Why does my bathroom keep getting mould?
Many Abu Dhabi apartments, from older towers downtown to newer blocks on Al Reem Island, have internal bathrooms with no window, so steam has only the exhaust fan to escape through. If the fan is weak, blocked with dust or switched off straight after a shower, moisture settles on the ceiling, grout and silicone, and mould follows within weeks.
In Al Ain's drier air mould is less common indoors, but it still appears around leaking fittings and in bathrooms that are always closed.
Is there mould in my AC?
Signs include black or grey spots on the vent grilles, a musty smell when the AC starts, and dust that settles quickly. AC units cool air by removing moisture, so the coils, drip tray and ducts stay damp, and the dust they collect gives mould something to grow on. In the UAE the AC runs almost all year, so this builds up quickly, particularly on the coast.
Wiping the grille removes what you can see, but the source is usually further inside, in the ducts and coil.
How do I clean mould safely and stop it coming back?
For small patches on tiles and grout, open the door and run the fan, wear gloves, and scrub with a bathroom mould cleaner or diluted bleach. Never mix bleach with other cleaners, especially ammonia or acid-based limescale removers. Rinse and dry the area completely.
• Run the exhaust fan during showers and for a while after, and clean its cover regularly. • Squeegee or wipe down shower glass and walls after use. • Fix dripping taps and leaking seals. • Replace silicone that has turned black inside, because the mould is in the sealant. • Clean AC filters regularly and have the ducts and coils cleaned when you notice smells or spots.
When should you call a professional?
• Mould comes back within a few weeks of cleaning. • It covers a large area of ceiling, wall or grout. • Grout and silicone are stained deep, not just on the surface. • The AC smells musty, or you see spots on several vents. • Someone at home has asthma or allergies.
Friends' bathroom deep cleaning descales fittings, scrubs and whitens grout, removes mould and disinfects. AC duct cleaning clears dust, mould and debris from the ducts, vents and coils. Call 050 112 7654 to book.
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Call 050 112 7654 or request a quote. Serving Abu Dhabi and Al Ain since 2003.
Frequently Asked Questions
Is black mould in the bathroom dangerous?
Mould can irritate the nose, throat and skin and trigger asthma and allergies, so it's worth removing promptly. If someone has symptoms, speak to a doctor.
Why does my AC smell musty?
Usually because dust and moisture have built up in the coil, drip tray or ducts and mould has started to grow. Cleaning the filter helps, but the ducts and coil often need cleaning too.
Can you remove mould from grout without replacing it?
In most cases deep scrubbing and whitening restores the grout. Silicone that has gone black inside usually needs replacing, and we'll tell you honestly after seeing it.