Dubai's coastal humidity and homes cooled to 22 degrees create a perfect environment for mould. Warm, humid air meets cold surfaces, condenses and stays damp. Bathrooms and AC units are where we see it most. The good news is that most mould problems can be removed and kept away with the right repairs and a few habits.
Why Mould Loves Dubai Homes
Mould needs moisture, warmth and something to feed on, such as soap residue or dust. In Dubai, humid air, long showers, poor extraction and AC condensation supply all three. Once mould takes hold in grout or silicone, surface cleaning only hides it for a few days.
Mould in Bathrooms
Silicone
Black silicone around the bath, shower tray or basin is the most common problem. Mould grows into the silicone itself, so it cannot be scrubbed out. The fix is to cut out all the old silicone, clean and dry the joint fully, and apply new mould-resistant silicone. See our caulking service.
Grout
Porous cement grout soaks up water and soap. If grout stays dark after cleaning, it needs mould removal or regrouting. In showers, epoxy grout resists mould far better.
Ceilings and Walls
Mould on bathroom ceilings usually means poor ventilation or a leak above. Check the extractor fan works, and run it during and for 15 minutes after showers.
Mould in AC Units
Signs
- A musty smell when the AC starts
- Black spots on the louvres
- Grey dust blowing from vents
- Allergy symptoms that ease when the AC is off
The Fix
Mould grows on the cold coil, the blower wheel and in the drain tray. A proper clean removes the unit covers, washes the coil and blower, clears the drain and applies an anti-microbial treatment. See AC mould removal and AC drain tray cleaning.
For ducted systems, mould and dust can also build up inside the ducts. See AC duct cleaning.
Habits That Keep Mould Away
- Squeegee shower glass and tiles after use.
- Run the bathroom extractor fan and leave the door open after showers.
- Run AC fan mode for 10 minutes before switching off to dry the coil.
- Clean AC filters every few weeks in summer.
- Avoid very low AC set points in humid rooms, which increase condensation.
- Fix leaks quickly, especially from AC drains and under sinks.
A Simple Weekly Anti-Mould Routine
- Daily: squeegee the shower, run the extractor fan for 15 minutes after showers and leave the door open.
- Weekly: wipe silicone and grout with a mild cleaner, and wash bath mats and shower curtains.
- Monthly: clean AC filters in summer, check under sinks for drips and check AC units for drips or smells.
- Every few months: book an AC service and reseal cement grout once a year.
This routine takes a few minutes but prevents most of the mould problems we are called to fix, and keeps bathrooms and AC units fresh through the humid months.
Frequently Asked Questions
Is Mould in the AC Harmful to Health?
Mould in AC units can release spores and musty smells into the air, which may irritate allergies and breathing, especially for children and older people. Cleaning the coil, blower and drain tray and treating them reduces the problem.
Can I Just Paint Over Bathroom Mould?
No. Paint over mould usually fails, and the mould grows back through it. Clean and treat the area, fix the cause of the moisture, then use a primer and a mould-resistant bathroom paint.
Why Does Silicone Go Black so Quickly?
Mould grows into silicone that stays wet, especially if it was applied over old silicone or onto a damp joint. Removing all old silicone, drying the joint fully and using mould-resistant sanitary silicone makes the new seal last much longer.
How Often Should AC Units Be Cleaned to Prevent Mould?
In Dubai, a full clean every three to six months keeps most units free of mould. Clean filters every few weeks in summer, and run fan mode before switching off to help dry the coil.
When to Get Help
If mould keeps returning within weeks of cleaning, the cause is usually failed silicone, porous grout, a blocked AC drain or a leak. Fixing the cause is what stops it for good. Send us photos and we will tell you what needs doing.