DIY Mould Testing vs Hiring a Pro – What’s the Best Choice for Your Home?
, by Tatianna Gerard, 14 min reading time
Mould can pose serious health risks and compromise the integrity of your home. Whether you've noticed a musty odour, persistent dampness, or visible mould patches, the next logical step is to determine the extent of the issue. But before diving into remediation, it’s crucial to test for mould properly to understand what you're dealing with.
Mould testing helps answer an important question: Can you handle this yourself, or do you need professional intervention? A DIY mould test kit can provide an initial assessment, helping homeowners detect spores in the air or on surfaces before deciding on the next steps. However, in some cases, a professional mould inspection is necessary—particularly if the contamination is extensive, hidden within walls, or linked to ongoing moisture problems. Choosing the right approach can save you time, money, and potential health risks while ensuring your space is safe and mould-free.
Why mould testing matters
Mould thrives in damp environments, often developing in places with excess moisture, poor ventilation, or after water damage. Without testing, hidden mould can continue to grow undetected, affecting indoor air quality and triggering respiratory issues, allergies, and other health concerns. More importantly, identifying mould at an early stage can prevent costly structural damage and reduce the need for invasive remediation efforts.
Testing is particularly important if you’ve recently experienced water damage, increased humidity, or condensation issues—all of which can create the perfect breeding ground for mould spores.
Extreme weather and rising mould risk in Australia
Mould contamination is becoming an increasingly common issue in Australia, with extreme weather events playing a significant role in its prevalence. The rise in cyclones, hailstorms, storm surges, and flooding has led to a higher risk of water-damaged homes, particularly in climate-sensitive and flood-prone areas. As homes become more vulnerable to moisture intrusion, the likelihood of mould growth skyrockets, posing both immediate and long-term health risks to residents.
Based on the findings backed by research from the 2022 study on Prevalence, Risk Factors, and Impacts Related to Mould-Affected Housing in Australia, Australia’s seasonal average relative humidity (RH) further contributes to the issue, creating ideal conditions for mould to flourish. When RH levels exceed 70%, moisture accumulates on surfaces, fostering the growth of mould and bacteria.
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During summer, RH levels exceeding 70% are no longer confined to the warmer regions of northern NSW, QLD, NT, and northern WA. These high-humidity conditions now extend along the eastern coastal communities, reaching as far south as VIC and TAS.
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In winter, high RH levels are not just a concern for tropical and coastal regions. They extend from southern WA, southern SA, VIC, ACT, NSW, and TAS, all the way through to northern QLD, creating persistently damp indoor environments that encourage mould growth.
DIY mould testing kits
When you suspect mould in your home, DIY mould testing kits can be an affordable and accessible way to get an initial assessment before deciding on the next steps. These kits are designed for homeowners who want a quick and simple method to check for mould without the immediate need for a professional inspection.
1. Affordable and accessible
One of the biggest advantages of DIY mould test kits is their cost-effectiveness. Compared to professional mould testing services, which can be expensive due to the expertise and specialised equipment involved, a DIY test kit allows you to identify potential mould issues at a fraction of the cost (roughly around $30-$50, depending on the brand). These kits are widely available online and in stores, making them easy to purchase and use whenever needed.
2. Easy to use at home
DIY mould testing kits are designed with simplicity in mind. Most kits include dip slides or petri dishes that capture mould spores from the air or surfaces. You don’t need any technical expertise—just follow the step-by-step instructions to collect your sample and observe any changes over the recommended incubation period. This makes DIY testing a practical option for homeowners, renters, and even businesses that want to conduct a preliminary mould check without bringing in external help.
3. Provides quick results
Unlike professional testing, which can take days or even weeks to complete, a DIY test kit delivers results much faster. Many kits allow you to see initial signs of mould growth within 24 to 48 hours, while full incubation may take up to 120 hours. This means you can quickly determine whether mould is present, allowing you to take immediate action to mitigate further growth or consider professional remediation if necessary.
4. Limitations: May not identify mould type or severity accurately
While DIY mould testing kits are a useful first step, they do have limitations. These kits can confirm the presence of mould, but they don’t always provide details on:
✔ The type of mould species (e.g., allergenic vs. toxic mould).
✔ The severity of contamination—whether it’s a minor issue or a sign of a larger hidden problem.
✔ The exact source of the problem, especially if mould is growing inside walls, under flooring, or in HVAC systems.
Since mould growth can vary in toxicity and health impact, a DIY kit alone may not be enough if you suspect a widespread issue or are experiencing persistent health symptoms. In such cases, a professional assessment may be needed to get a clearer picture of the extent of mould contamination.
Professional mould testing
While DIY mould testing kits are a great starting point, they have limitations when it comes to identifying the type, extent, and severity of a mould issue. This is where professional mould testing comes in. It is normally conducted by certified experts, where they would provide a thorough assessment of your indoor environment, giving you precise, science-backed insights into the mould problem at hand.
More expensive but thorough
Unlike a simple DIY test, professional mould testing is a more in-depth process—and with that comes a higher cost. The price of a professional inspection varies depending on factors such as the size of the property, the number of samples taken, and whether laboratory analysis is required. While this option is more expensive, it offers a much more detailed evaluation, which is often necessary for serious mould infestations, legal disputes, or ongoing health concerns.
Below is a general guide to pricing:
- Basic mould testing services, which include inspection and lab analysis, typically start at $300 and can go up to $1,500 or more, depending on the level of assessment needed.
- Residential mould inspections in Australia generally fall within the range of $300 to $3,000, with standard home inspections often costing between $1,300 and $1,800, depending on the consultant and the size of the property.
- Commercial mould inspections tend to start at $1,000, but costs can rise significantly based on the scale of the assessment and the size of the building.
Conducted by experts with specialised equipment
Professional mould testing is performed by trained technicians who use specialised tools and techniques to assess air and surface contamination. Some of the equipment used includes:
- Air sampling pumps – These collect airborne mould spores to determine indoor air quality.
- Surface swabs & tape lifts – Used to gather samples from affected areas for lab analysis.
- Infrared moisture meters – Identify hidden moisture pockets within walls, ceilings, and floors that may be fostering mould growth.
- Thermal imaging cameras – Detect areas of excess moisture that could be encouraging mould to thrive.
This scientific approach allows professionals to pinpoint hidden mould growth, which a simple DIY test may not detect.
Can identify mould species and spore count
One of the biggest advantages of professional testing is that it doesn’t just confirm the presence of mould—it tells you exactly what kind of mould you’re dealing with. This is critical because different mould species have varying levels of toxicity and health risks.
For example:
- Allergenic moulds (e.g., Cladosporium, Aspergillus) can trigger allergies and asthma.
- Pathogenic moulds (e.g., Fusarium, Trichoderma) may cause infections in people with weakened immune systems.
- Toxigenic moulds (e.g., Stachybotrys chartarum, commonly known as “black mould”) produce mycotoxins that can cause serious respiratory and neurological health issues.
Along with species identification, professionals measure spore counts in the air, which helps determine the severity of contamination. This is especially useful in cases where there are no visible signs of mould, but symptoms such as persistent allergies, respiratory issues, or musty odours suggest an underlying problem.
Often includes recommendations for remediation
Unlike DIY testing, which only tells you if mould is present, professional assessments go a step further by providing tailored recommendations on how to handle the issue. After analysing the test results, professionals often:
- Identify the source of excess moisture (e.g., leaks, condensation, or poor ventilation).
- Suggest appropriate remediation steps—whether you can DIY or need expert removal services.
- Provide preventative strategies to stop mould from returning (e.g., improving ventilation, installing dehumidifiers, or addressing structural issues).
Many mould inspectors also work with or can refer you to remediation specialists who can safely remove mould using industry-grade techniques such as HEPA vacuuming, antimicrobial treatments, and air purification.
When to choose DIY vs professional testing
Now that we’ve covered the differences between DIY and professional mould testing, the next step is determining which option best suits your situation. The choice largely depends on the extent of the issue, potential health risks, and whether legal or rental considerations are involved.
When DIY mould testing is a good option
A DIY mould test kit can be a great first step if you:
✔ Want to perform a general check – If you suspect mould but aren’t sure of its presence, a DIY test can help you confirm whether spores are present in the air or on surfaces.
✔ Need early detection – Catching mould before it becomes a major issue can save you time and money. Testing after humidity spikes, minor leaks, or musty odours can help identify potential problems early.
✔ Are looking for post-remediation verification – If you’ve already conducted mould removal and want to ensure the treatment was effective, a DIY test can help verify that mould levels have returned to normal.
✔ Have localised mould in a manageable area – Small patches of mould (e.g., in a bathroom or on a window sill) can often be treated without professional intervention, and DIY testing can help monitor the situation.
When professional mould testing is necessary
In some situations, a professional mould inspection is the best course of action. Consider professional testing if you:
✔ Have persistent health concerns – If household members are experiencing unexplained allergies, respiratory issues, headaches, or skin irritations, airborne mould exposure could be a factor. A professional test can assess air quality and identify harmful mould species.
✔ Suspect widespread or hidden mould growth – Large or reoccurring mould infestations often indicate an underlying moisture issue. Professionals can identify the source (e.g., water leaks, poor ventilation) and recommend appropriate solutions.
✔ Are dealing with legal or rental disputes – If you’re a tenant, landlord, or property manager and need documented proof of mould presence for legal reasons, professional testing provides an official report that can be used in disputes.
✔ Have had severe water damage or flooding – Homes affected by flooding, storm damage, or burst pipes are at a high risk of mould growth. Professional testing ensures that the moisture problem has been fully resolved and that the indoor environment is safe.
✔ Need an in-depth analysis of mould species and spore count – If you need to know exactly what type of mould is present and how severe the contamination is, professional testing provides detailed species identification and air quality assessment.
✔ Plan to sell or rent out a property – Ensuring that a property is mould-free before selling or leasing it can prevent potential disputes, health risks, and damage claims in the future.
Making the right choice
Mould can be a hidden threat, impacting both health and property if left unchecked. If you’re dealing with minor concerns or want a quick check, a DIY test kit is an easy and cost-effective option. However, if mould is widespread, persistent, or causing health problems, it’s best to seek professional testing for a comprehensive analysis and expert recommendations.
Shop the SAN-AIR Mould Testing Kits collection
Need lab analysis? Send your SAN-AIR Test Kit for professional identification of mould or bacteria
While the SAN-AIR Mould & Bacteria Test Kit is an excellent tool for detecting the presence of mould and bacteria, you may want further analysis to identify the exact type of mould growing in your space. This can be particularly useful if you’re concerned about toxic mould species or experiencing persistent health issues.
If you need lab testing, you can send your used SAN-AIR test kit to a professional laboratory for species identification and spore analysis. We recommend contacting one of these trusted labs in Australia:
Important Reminder: Please note that when sending your test kit to a lab, you will need to provide your own incubator (or thermos box) to store and protect the sample during transport. This is not included with your SAN-AIR test kit purchase, so you will need to source one separately.