Top Lists
Top 8 Humidity Habits That Grow Mould in Your Singapore Home
Singapore's outdoor RH averages 80–90%. Indoors, it should stay under 60% to stop mould — but eight everyday habits push it past 70%. Fix these first, before you spend a dollar on a dehumidifier.
Quick Answer
The everyday habits that grow mould in Singapore homes are drying laundry indoors without ventilation, shutting the bathroom door after a shower, switching the aircon off at the wall instead of running fan-only, keeping the bomb shelter sealed, pushing furniture flat against external walls, storing damp shoes and bags in closed cabinets, and never opening windows on dry days. Each one traps moisture; fixing them costs nothing and prevents most recurrence after treatment.
Based on: Dehumidifier Effectiveness Study Singapore Weather & Mould Parameters (study)
Hot showers with the door left open
Bathrooms hit 95%+ RH during a hot shower. If the door is open, that spike migrates into your bedroom and wardrobe. Close the door, run the exhaust fan for 20 minutes after.
Drying laundry indoors under a ceiling fan
A 7 kg wash releases 3–4 litres of water into your air. A ceiling fan spreads it, doesn't remove it. Dry in the yard or bathroom with exhaust fan on.
Aircon set to 25°C+ with fan on 'low'
High set-point + low fan = coil doesn't dehumidify, room RH climbs past 70%. Drop set-point to 23–24°C on auto fan first 30 minutes.
Sealing the bomb shelter / store room shut
No ventilation by design. Sealed shut, RH pushes 85%+ within days. Leave the door cracked 24/7.
Curtains touching cold window frames
Curtains against a condensing frame wick water and grow mould in 4–6 weeks. Keep 5 cm gap.
Storing shoes and bags inside the wardrobe
Leather and canvas hold moisture. Wardrobe RH hits 80%+ overnight. Air shoes 12 hours before storing.
Bed pushed against an external wall under aircon
External wall near aircon can sit below dew point. Pull bed 5 cm off wall.
Ignoring the musty smell in the first minute of aircon
That wet-sock smell is Cladosporium on the blower wheel. Book aircon mould servicing from S$90/unit.
Ready to fix it?
Limited-time promo — Essential first full ceiling or wall surface from $199 (normally $299). Full mould removal + Nippon anti-mould paint + protective sealer, 6-month warranty.Frequently Asked Questions
- What's the ideal indoor humidity in Singapore?
- 50–60% RH. Above 65%, mould colonises porous surfaces within weeks.
- Does opening windows help or hurt?
- Depends on outdoor RH. Under 75% helps; after rain it makes it worse.
- Is a dehumidifier necessary?
- For most HDB/condo units, no — if you fix these 8 habits.
- How fast does mould grow after RH tips over 70%?
- Damp fabric: 24–72 hours. Painted concrete: 2–4 weeks.
- Which habit causes the most mould jobs Pico X Health sees?
- Habit #1 — hot showers with poor extraction.
Watch: Prevent mould during Singapore's rainy season
A quick walkthrough of the humidity habits that matter most in the monsoon months.
What changes indoors during the monsoon months and how to keep relative humidity under control so damp walls, wardrobes and ceilings do not turn mouldy. Watch on YouTube · More Pico X Health videos