When mould appears in your home, finding the moisture source is essential for lasting remediation. In Singapore, mould can result from plumbing leaks, ambient humidity, or often both. This guide helps you identify which is causing your problem.
Signs of Leak-Related Mould
Mould caused by plumbing leaks typically shows these characteristics:
Location Patterns
- Near plumbing fixtures (under sinks, around toilets)
- Below bathrooms on lower floors
- Along pipe routes in walls or ceilings
- In kitchen cabinet bases
Visual Clues
- Water stains with defined edges
- Expanding ring patterns
- Concentrated in specific spots rather than spread out
- Paint bubbling or wallpaper peeling in localized areas
Other Indicators
- Unexpectedly high water bills
- Sound of running water when all taps are off
- Warm spots on floor (hot water pipe leak)
- Mould appears suddenly after no previous issues
Signs of Humidity-Related Mould
Mould from high humidity shows different patterns:
Location Patterns
- Corners of rooms, especially exterior walls
- Behind wardrobes and large furniture
- Bathroom ceilings and walls
- Around windows (condensation zones)
- Bomb shelters and enclosed storage spaces
Visual Characteristics
- Spread across larger areas
- Often starts in corners and edges
- May appear in multiple rooms
- Fuzzy or powdery growth pattern
Environmental Factors
- Worsens during monsoon season
- Appears in rooms with poor ventilation
- Common in homes without regular AC use
- Develops on cold surfaces in air-conditioned spaces
How to Diagnose the Cause
Step 1: Check Plumbing First
- Inspect under all sinks for dampness
- Look for water marks around toilet bases
- Check ceiling below any bathrooms above
- Monitor water meter when no water is running
Step 2: Assess Humidity Conditions
- Use a hygrometer to measure room humidity
- Note if mould worsens in humid weather
- Check ventilation in affected areas
- Look for condensation on windows or cold surfaces
Step 3: Professional Assessment
- Thermal imaging can detect hidden moisture
- Moisture meters measure water content in materials
- Pressure testing identifies pipe leaks
Frequently Asked Questions
How can I tell if mould is caused by a leak or humidity?
Leak-related mould typically appears in localized areas near plumbing, has defined edges, and may have water stains. Humidity-related mould is more widespread, appears in poorly ventilated areas, and often develops on exterior walls or in corners.
What are signs of a hidden water leak causing mould?
Signs include: unexpectedly high water bills, sound of running water when none is in use, warm spots on floors (hot water leak), mould near plumbing fixtures, water stains that grow over time, and musty odors concentrated in specific areas.
Can high humidity alone cause mould in Singapore?
Yes, absolutely. Singapore's 80-90% relative humidity provides perfect conditions for mould growth without any leaks. Poor ventilation, lack of air conditioning, and temperature differences between rooms all contribute to humidity-related mould.
Why do I get mould on walls near air conditioning?
Temperature differences between the cold AC area and adjacent spaces cause condensation. When humid air contacts cold surfaces, water droplets form. This condensation provides moisture for mould growth, even without any leaks.
Should I call a plumber or mould specialist first?
If you see active water or water stains, call a plumber first to stop the leak. If there's no obvious water source but persistent mould, a mould inspection can identify the moisture source – whether it's a hidden leak or humidity issue.