Mould & Moisture Assessment

Mould & Moisture Assessment

The assessment is all about identifying the sources of moisture, humidity or condensation, measuring and recording the key elements that make up the environment, surface microbial testing for ATP and then coming to a hypothesis on what could be happening before doing laboratory sampling. 

The night before the assessment, we ask the occupants to keep all doors and windows closed up, from about 8pm onwards, but ideally 24 hours. This keeps mould growing indoors, to be ‘kept indoors’ as they typically release their mould spores in the evening and early morning. Therefore, there tends to be a concentration of mould spores and hyphae fragments in the air by doing this. Some mould spores won’t aerosolise so it comes down to the experience of the building biologist to determine potential areas of interest. Severely water damaged buildings will have extremely high levels of mould spores and hyphae fragments. A good indicator of this is the damp musty smells in a room, or if you start sneezing, coughing or have runny nose after walking into a room.


Before the Assessment

Before the assessment, we request the completion of the questionnaire and a client work order form.

50% deposit also needs to be paid and assessment date is scheduled.

The night before the assessment, we’ll ask you to keep all doors and windows closed. Also to avoid using air purifiers, heating, cooling, dehumidifiers and also humidifiers. This is so we don’t influence or affect the indoor air when laboratory air samples are taken. It’s also to trap and concentrate any mould spores and hyphae fragments (filaments of mould) indoors. There’s usually a higher quantity of mould spores and hyphal fragments when there is mould growth.


Environmental Measurements

Outdoor vs Indoors.

It’s comparing outdoors versus indoors, based on the occupants activity, and we typically see a big difference in moisture or humidity levels indoors. 

We will use a hygrometer to measure the following in various areas of the home:

  1. Temperature
  2. Relative humidity – this is humidity relative to temperature
  3. Dew Point – the temperature point at which water in the air will condense into water droplets.
  4. Absolute Humidity – the amount of water/moisture in the air

To see a sample of the measurements, click here.


Moisture Meter Readings

Often, how the surface water is drained is just as important as the environmental measurements from above. Measuring building materials such as exterior wall cladding or internal gyprock walls will help identify where some of the problem areas are. 

floorboard moisture reading wet


ATP Surface Measurements for Microbial Activity

We use ATP surface testing to determine the level of microbial activity (mould or bacteria). It’s the same meter that food hygienists will use to test commercial kitchens. ATP is the energy molecule that all organisms use. Humans will also generate ATP via the mitochondria in their cells. 

High ATP levels (measured in Relative Light Units/RLU) is indicative of microbial activity. That is, there is something growing on the surface. 

Typically, high dust levels and high moisture or humidity will result in high ATP. If you provide food (dust) and water (moisture or condensation), you provide the ability of microbial organisms to grow. 

Sample output here

Some Building Biologists may charge you ($10-20/sample) for this testing, while other building biologists may NOT test at all. For clients of Balanced Building Biology, this testing is FREE. It’s our way of proving to you where we see an issue. Sometimes, despite this testing, our experience will tell us that we suspect something, and the only way to confirm this, is to do laboratory sampling. 



Discussion with Client/Occupant

The outcome of the initial measurements will be discussed with you, and we will take you through certain areas of the home that may be causing the problem. 

You don’t have to remember everything but it’s just to help you visibly see where some of the problems are. 


Laboratory Air/Surface Sampling

Based on our discussion and our recommendations, we get agreement from the client/occupant to go forward with any air or surface sampling for laboratory analysis.

This is an extra cost on top of the assessment and it costs $120 per laboratory sample. 

The building biologist will determine which laboratory to have the sample analysed, and there may be 2 laboratories used for this purpose. 

The most cost effective lab for both the client and the building biologist will be used.

Mould Laboratories are located in Melbourne, and all lab samples are sent via Express Post the next day. It usually takes 5 business days for results to be returned unless mould spores are cultured (for 7 days). 

Without lab confirmation on the presence of mould spores and hyphae, we cannot say that there is “mould” in the building. Laboratory samples are the definitive confirmation. 

Sample: Report1 / Report2 


Final Report

Once the laboratory results come back, we review all the environmental data measured on the day, the laboratory results and the observations around the building to come to a final conclusion on what is occurring in the building and what can be resolved.

Laboratory results are interpreted & summarised (sample here without interpretation).

Suggested actions are customised and formulated for your home. This may involve recommendation for IICRC Mould Remediators to conduct the Mould Remediation (Cleaning and Removal). 

Read more on the mould inspection report.

Reports are typically 40 – 70 pages. This report would need to be shared with IICRC Mould Remediators for them draft their ‘Scope of Works’ for remediation. 



Contact Us

If this is of interest, then call us to make a booking or to have further discussions. Sometimes, just hearing someone over the phone and discussing your concerns will help you make your decision.

Contact Us

Contact Us