Self-Check Guide for Mould & Humidity Problems in Homes and Rentals
Why Early Detection Matters
Mould and excess humidity can cause major damage to properties and impact health — especially in rental properties where responsibility between landlords and tenants can get blurred. By performing a quick self-check, you can avoid costly repairs, health issues, and disputes.

Who Is This Guide For?
DIY Mould & Humidity Self-Check Checklis
Use the list below to do a basic inspection:
✅ Visual Signs
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Stains, dark patches, or bubbling paint on ceilings/walls
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Mould behind furniture, especially near external walls
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Visible condensation or dripping windows
✅ Odours & Air Quality
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Musty or “earthy” smells in rooms or wardrobes
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Lingering damp smell, especially in bathrooms/laundries
✅ Moisture Sources
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Leaks from pipes, water heaters, or ceiling cavities
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Poor ventilation in kitchens and bathrooms
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Damp subfloors or crawlspaces
✅ Test Tools (Optional but recommended)
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Use a digital hygrometer to measure indoor humidity
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Ideal range: 40%–60% relative humidity
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Readings over 60% = higher mould risk
Click here to see some of the tools that we use on mould inspection sites
What to Do If You Find Signs of Mould
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Inform your property manager or landlord immediately (if renting) Always keep photos and document all findings.
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Avoid cleaning large areas yourself — it can worsen the spread
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Book a professional Mould Inspection or Monitoring Service
🔎 Common Signs of Mould Growth or Condensation:
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Black spots or fuzzy patches forming on bathroom ceilings, bedroom corners, or around window frames.
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Musty smell lingering in wardrobes, under sinks, or behind furniture placed against external walls.
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Condensation on windows and glass doors in the mornings — often a sign of poor ventilation and high indoor humidity.
Click here to see some of our photos from previous mould inspections
Real Estate & Strata Support
We work directly with:
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Real estate agencies to provide tenant education materials
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Strata managers for whole-building assessments and prevention
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Property investors to protect asset value and meet compliance
Download our printable guide below to include in tenant welcome packs or lease documentation.

Download Our Tenant Mould Guide (Free PDF)
📥 Click to download
Includes:
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Self-checklist
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Prevention tips
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What to do if mould appears
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Contact info for professional assessment
Need Help?
Use our Inspection Booking Form or call us for priority support.
📞 1300 333 654
📍 Serving all of Sydney and surrounding suburbs
FAQ
1. Who is responsible for mould in a rental property — the landlord or the tenant?
It depends on the cause. If mould is due to structural issues, leaks, or poor ventilation, the landlord is usually responsible. If it's caused by how the property is being used (e.g. poor airflow, drying clothes inside), the tenant may be liable.
2. How do I know if I have a mould or humidity problem?
Common signs include musty odours, black or green spots on walls or ceilings, condensation on windows, or peeling paint. Use our self-check guide to inspect key areas in your home or unit.
3. Can tenants clean mould themselves?
Small patches can sometimes be cleaned with care, but using the wrong products or methods can make things worse. For persistent or larger problems, it’s best to book a professional inspection.