Air Sampling for Mould — When Is It Necessary and What Do the Results Mean?
Not all mould problems are visible. In many cases, mould spores are floating in the air long before you see stains on walls or ceilings. That’s where air sampling comes in. But when is air testing for mould actually necessary — and how do you make sense of the results?
At Confluence Environmental, we help homeowners, property managers, and builders across NSW get clear answers through professional mould inspections and air quality testing. Here’s what you need to know.
What Is Mould Air Sampling?
Air sampling for mould is a method of testing the air in a room to detect and measure airborne mould spores. These spores are invisible to the naked eye but can trigger allergies, respiratory problems, and other health issues — especially in enclosed or poorly ventilated spaces.
When Is Mould Air Testing Necessary?
Air sampling isn’t always needed in every mould inspection — but there are specific situations where it’s highly recommended:
1. You Suspect Mould but Can’t See It
If there’s a musty smell, ongoing health issues, or recent water damage — but no visible mould — air sampling can help detect a hidden problem behind walls, under floors, or in ceilings.
2. You Need Scientific Evidence for Health or Legal Reasons
Air test results are quantifiable and objective, which makes them useful for:
Strata disputes
Landlord-tenant complaints
Insurance claims
Legal proceedings
3. You Want to Confirm Indoor Air Quality
For sensitive individuals — such as people with asthma, allergies, or immune conditions — air sampling helps assess whether a space is safe to occupy or work in.
4. Post-Remediation Verification
After mould removal, air sampling can confirm that airborne spore levels have returned to normal — providing peace of mind and documentation that remediation was successful.
How Is Mould Air Sampling Done?
At Confluence Environmental, our consultants use calibrated air pumps and spore trap cassettes to collect air samples in affected areas, often alongside an outdoor control sample.
Each test typically includes:
Indoor sample(s) — near suspected sources or in occupied rooms
Outdoor sample — to provide a baseline for comparison
Optional follow-up sampling — in HVAC systems or concealed spaces
The samples are sent to a NATA-accredited laboratory for analysis.
What Do the Results Mean?
The lab identifies and quantifies mould spores by type and concentration (measured in spores per cubic metre).
Here’s how to interpret typical results:
Spore Count Comparison: Indoor vs Outdoor
If indoor spore counts are significantly higher than outdoors, it suggests active indoor mould growth.
If indoor counts are similar or lower, mould may not be present or is not currently active.
Types of Mould Detected
Some mould types are more concerning than others:
Mould TypeCommon SourceRisk LevelCladosporiumDamp areas, HVACLow to ModeratePenicilliumWater-damaged drywall, insulationModerateAspergillusDust, HVAC systemsModerate to HighStachybotrys (Black Mould)Water-saturated materialsHigh
Finding toxic moulds (like Stachybotrys or Chaetomium) indoors is a clear red flag and requires urgent attention.
Spore Concentration Thresholds
There are no fixed Australian exposure limits for indoor mould spores, but professional interpretation considers:
Spore type
Spore count vs outdoor air
Occupant health risks
Source moisture conditions
That’s why it’s essential to have an experienced consultant interpret the data — not just rely on raw numbers.
Do You Need Mould Air Sampling?
Air sampling isn’t always necessary if:
The mould is clearly visible
The source is obvious and contained
You’re already undertaking remediation
But it’s highly valuable when:
The problem is hidden or disputed
Health concerns are present
You need documentation for legal or insurance reasons
How Confluence Environmental Can Help
We provide independent mould inspections and air sampling across NSW — including the Central Coast, Newcastle, Hunter Valley, and Sydney.
Our services include:
Moisture mapping and leak detection
Mould air testing (spore trap and viable culture)
Laboratory analysis and expert interpretation
Remediation guidance or clearance verification
Detailed reporting for insurance or legal use
Need a Mould Air Test?
Contact us today for clear answers and certified reporting.
Book online here or call 0493 042 642.
Final Thoughts
Mould can impact your health even when it’s invisible. Air sampling is a powerful tool for diagnosing hidden problems, verifying remediation, or supporting your case in a dispute.
At Confluence Environmental, we combine science, experience, and honesty to help you understand what’s really in your air — and what to do about it.