Part 5: How to Test for Mold in Your Home: Our Experience, Testing Methods, and What We Wish We’d Known Sooner
When it comes to mold recovery, identifying the source is just as important as treating the symptoms. If you’re still not getting better—or you’re just beginning this journey—understanding how to test for mold in home environments can be the difference between ongoing illness and finally making progress.
For us, it took over five years before the puzzle pieces came together. We lived in our home without major issues until after our youngest daughter was born. Needing extra space, we converted attic rooms into a home office, which meant we started leaving doors open and regularly using the upper level. That small shift may have changed everything.
We didn’t realize it then, but the mold count was highest in that upstairs space. Once we began circulating air and moving in and out of the area, we unknowingly unleashed years’ worth of mold spores into our living environment.
Our Mold Testing Experience: Spore Sampling and Discovery
After testing revealed the presence of mycotoxins in our bodies, we knew the next step was to test for mold in our home. Eventually, we hired a mold inspector who conducted spore trap sampling and a full mold inspection—and the results confirmed elevated mold counts, particularly in the basement and upper level. Mold was also found in the HVAC system, likely contributing to widespread circulation throughout the house. It finally made sense.
Types of Testing: How to Test for Mold in Home Environments
Here’s a breakdown of the most commonly used testing methods, starting with our favorite and moving down based on reliability and usefulness:
✅ EMMA Test (Environmental Mold and Mycotoxin Assessment) – Our Favorite Choice
- What it is: A dust test that detects both mold spores and the presence of mycotoxins in the environment.
- Estimated Cost: $300–$400
- Pros: Tests for mold and toxins in one sample; convenient, especially for sensitive individuals.
- Cons: Costly; requires lab interpretation; newer and less widely used than ERMI.
👍 ERMI (Environmental Relative Moldiness Index) – Strong Option
- What it is: Uses DNA testing on dust samples to identify mold species.
- Estimated Cost: $250–$350
- Pros: Provides detailed data on mold types and quantities; well-established.
- Cons: Doesn’t test for mycotoxins; results can be complex to interpret.
⚠️ Spore Trap Air Testing – Basic Indicator
- What it is: Collects airborne spores onto a slide or cassette.
- Estimated Cost: $150–$300 (plus inspection fee)
- Pros: Widely available, used by many inspectors.
- Cons: Only captures mold present in the air at the time of testing; can miss hidden or non-airborne sources.
👀 Tape or Swab Sampling – Use for Visible Mold Only
- What it is: Surface samples collected and analyzed for mold presence.
- Estimated Cost: $50–$150
- Pros: Good for confirming visible mold.
- Cons: Limited to what’s on the surface; doesn’t reflect overall exposure.
🧪 HERTSMI-2 – Great for Post-Remediation Verification
- What it is: A simplified scoring system based on five highly toxic molds, derived from the ERMI data set.
- Estimated Cost: $150–$250
- Pros: Easy to understand scoring system; helpful for determining if a space is safe post-remediation.
- Cons: Narrow focus on just five molds; doesn’t include mycotoxins.
Who Should Help You Test for Mold in Home Spaces?
While some of the tests listed above can be completed on your own using DIY kits, interpreting results and deciding on next steps often requires expertise. That’s where trained professionals come in. In addition to certified mold inspectors, you may benefit from working with a mold-literate doctor or a Certified Building Biologist like Martine Davis of Indoor Environmental Testing, Inc.. These experts can help you connect the dots between environmental findings and health symptoms, ensuring you don’t miss a critical piece of the puzzle.
It’s important to understand that standard home inspectors are not mold certified. While they may recognize visible mold or water damage, they often miss the hidden sources that cause chronic illness.
A mold-certified inspector, on the other hand, uses specialized tools like:
- Moisture meters
- Infrared cameras
- Air and dust sampling
- HVAC inspections
These tools can uncover what the eye can’t see—and what many families live with unknowingly for years.
DIY vs. Professional: How to Test for Mold in Home Without Missing Critical Sources
Some mold tests can be done on your own, especially those that involve collecting dust samples and sending them to a lab—such as the ERMI, HERTSMI-2, or EMMA test. These at-home kits can give you a general idea of your mold burden and help decide if professional help is warranted.
However, more in-depth testing—like spore trap air sampling, moisture mapping, and HVAC inspection—should be handled by a certified mold inspector.
💡 BUYER TIP: If you’re planning to buy a home, make both a standard home inspection and a test for mold in home spaces essential parts of your decision. After sharing our story, we had people say, “Well, they deserve it—they should’ve had a home inspection.” While it’s true that we waived the inspection at the time, the reality is that even if we had gotten one, it likely wouldn’t have detected the hidden mold that made us so sick. Mold often hides behind walls, under floors, or in HVAC systems—places that a routine inspection may never reach.
According to the EPA, mold can begin growing in as little as 24 to 48 hours after water intrusion.¹ And once it establishes itself, spores can remain dormant and reactivate with moisture, meaning that even “dry” homes may harbor hidden risk.
Beyond the Home: Mold Exposure in Schools and Workplaces
While it’s common to focus on the home when testing for mold, it’s important to recognize that other environments—like schools and workplaces—can also be significant sources of exposure. If you’re experiencing persistent symptoms but your home tests negative for mold, consider evaluating other places where you spend substantial time.
Schools, in particular, can harbor mold due to factors like aging infrastructure, inadequate ventilation, and moisture from leaks or high humidity. A study published in the journal Environmental Health Perspectives found that classrooms within the same school can vary significantly in mold spore counts, and visible mold was associated with higher spore levels. (source)
If you suspect that mold exposure at your or your child’s school or workplace is affecting health, it’s crucial to notify the appropriate authorities and seek medical advice. Testing these environments and addressing any issues found can be essential steps toward improving health outcomes.
Lessons Learned: What We Would Have Done Differently
Looking back, if we had understood how to test for mold in home environments properly, we could have prevented years of declining health, emotional stress, and financial loss. Consider these takeaways:
- If your health is suffering and tests show mold toxins in your body, test your home immediately.
- Prioritize dust testing methods like EMMA or ERMI over basic air sampling.
- Always go with independent inspectors—not remediation companies.
- Remember: appearances can be deceiving. Mold often hides in HVACs, behind walls, and under floors.
Testing earlier—especially before major home renovations—could have given us the information we needed to take action sooner.
If you’re unsure whether your home might be contributing to your symptoms, trust your instincts. Hire a certified inspector, ask the right questions, and don’t rely on appearance alone. Test for mold in home spaces when in doubt. Mold hides—and if you’re dealing with unexplained illness, it’s worth investigating.
Coming Next: Part 6 – What to Do After a Mold Diagnosis
We’ll walk you through the next critical steps: what to do when your home tests positive, how to protect your health, and the first actions that matter most.
¹ U.S. Environmental Protection Agency. “A Brief Guide to Mold, Moisture and Your Home.” EPA.gov