The Invisible Leak: Solving a Chronic Mould Problem in Eastwood

For a homeowner in Eastwood, it was a frustrating mystery. Extreme mould was aggressively growing on their dining and kitchen ceiling, and visible condensation marks were running down the walls, yet multiple checks had revealed no signs of a roof or plumbing leak. It's a common scenario that can leave people stumped, cleaning a problem that always returns.

This case study shows how we use a scientific, data-driven approach to solve mould problems even when the source of the moisture is invisible.

The Initial Inspection - Searching for the Source

The client booked our free mould inspection after becoming concerned about the rapid mould growth. Our certified mould inspector attended the property and conducted a thorough assessment. Using a thermal imaging camera and pin moisture meters on the walls, ceiling, and flooring, we confirmed the client's suspicion: the building was structurally dry. There was no active water leak or ingress. This meant the culprit had to be the indoor environment itself.

Step 2: The Data-Driven Diagnosis - A Week of Monitoring

To prove our hypothesis, we needed objective data over time. We installed a professional Protimeter BLE data logger in the main dining area. This advanced device is not a simple moisture meter; it was left in place for a full seven days to continuously record the temperature and relative humidity every 30 minutes. This process gives us a true understanding of the home's atmospheric conditions, capturing the crucial fluctuations between day and night that a simple spot check would miss.

Click here to learn more about our moisture data monitoring for mould investigation services.

Step 3: The Verdict - An Environment Out of Balance

After a week, we collected the logger and downloaded its data into a spreadsheet for analysis. The data told a clear and undeniable story: the relative humidity inside the property was constantly over 80% and was hitting a full 100% saturation point almost every night.

The air itself had become so saturated with moisture—likely due to poorly functioning extraction fans in the kitchen and bathroom combined with consistently closed windows—that it was condensing on the cooler ceiling surfaces. This was the "invisible leak," providing a constant drip-feed of moisture that allowed mould to thrive.

With this clear scientific evidence, we sat down with the client to explain the findings and our customised scope of work, based on the IICRC S500 and S520 standards, to achieve a guaranteed result at a reasonable price.

Step 4: A Meticulous Remediation Process

With the quote accepted, our team began the multi-day remediation process.

• Day 1: Contents Protection & Site Setup

  
  

  Our process began with the careful pack-out of all contents from the dining and kitchen area for off-site cleaning at our North Rocks warehouse. We then established a full containment zone using the Zipwall® system and established negative air pressure to prevent any cross-contamination.

  
  

• Day 2: A Targeted Cleaning Strategy

  
  

  Our IICRC certified technicians used a two-fold approach. For areas with superficial mould growth, we followed the IICRC S520 "sandwich" method: a thorough HEPA vacuum, followed by a damp wipe with an antimicrobial solution, and a final HEPA vacuum. For areas where the mould had penetrated deeply into the plaster, the material was cut out and safely removed.

  
  

• Day 3 & 4: The Air Wash

  
  

  With the sources removed, we ran multiple industrial HEPA air scrubbers inside the containment for a full 48 hours. This process "washes" the air, capturing any lingering microscopic spores and ensuring the environment is clean and safe.

  
  

• Day 5: The Final Verification

  
  

  The job concluded when an independent hygienist performed the Post-Remediation Verification (PRV), providing a clearance certificate that confirmed the home had been returned to a normal, healthy state (Condition 1).

Solving the Problem You Can't See

This Eastwood case study proves that the source of a serious mould problem isn't always a dramatic leak. By using a scientific and data-driven approach, we were able to diagnose the chronic high-humidity issue and provide a solution that not only cleaned the mould but also empowered the homeowner with the knowledge and recommendations needed to prevent it from returning.

Photos from this mould removal job site in Eastwood

photo of active mould growth on the ceiling and walls

photo of after mould has been removed from the ceiling and walls

If you're battling a persistent mould or musty smell issue in your Inner West home that you can't explain, contact our team for a detailed diagnostic inspection.

About the Author

Michael Nguyen is the founder of AAA Mould Removal and a leading expert in mould remediation and building science. His mission is to help Sydney residents maintain healthy indoor environments through scientifically-backed, professional remediation services.

With a unique combination of hands-on and academic expertise, Michael's qualifications are extensive:

• IICRC Certified: Water Damage Restoration, Applied Microbial Remediation & Applied Structural Drying.

• Microbiology: Completed specialised study in Microbiology at RMIT University.

• Licensed Builder & Carpenter with a Diploma in Building & Construction.

• Current University Studies: Double Bachelor’s degree in Medical Science and Environmental Science at Macquarie University.

This deep understanding of building structures, environmental science, and microbiology allows Michael to diagnose the root cause of mould problems, not just treat the symptoms. He specialises in residential and commercial mould removal, black mould treatment, and water damage restoration.

Need a true expert to assess your property? Contact AAA Mould Removal today for a comprehensive mould inspection.