Mold in your house will make you sick. But your eyes and nose will not be enough to detect it.
Mold is sneaky. It hides in areas you cannot see or smell!
You need to use specialized testing, known as ERMI and HERTSMI2 to find out if your home is making you sick.
However, before you begin testing you need to remove yourself from the source of exposure. Removing yourself from exposure needs to be your top priority if you are experiencing a mold allergy or chronic inflammatory response syndrome (CIRS).
If your symptoms improve when you leave and worsen when you re-enter, you are very likely dealing with mold in your house.
What you need to know about mold in your house
I want to be crystal clear – using your eyes and nose is not a reliable way to determine if your home has mold. That’s because mold growth often occurs out of sight. It can collect in ventilation ducts, attics, or crawl spaces – places you can’t see.
Laboratory testing is by far the most effective means in determining if you have mold in your house.
If you’re not sure that you are suffering from mold exposure, run through my preliminary screening tool below. And if you’re symptomatic, have your home lab testing your home for mold ASAP. I go into the specifics on the ERMI and HERSTMI2 tests at the bottom of this post.
Signs that there’s mold in your house
1. Your symptoms
A strange array of symptoms is perhaps the most obvious sign that there’s mold in your house. There are many vague symptoms of mold illness. Often, mold illness symptoms will be diagnosed as fibromyalgia, chronic fatigue syndrome (CFS), or irritable bowel syndrome (IBS).
Some of the more general – though less severe – symptoms of mold in your home include:
- Stuffy or runny nose (rhinitis)
- Excessive sneezing
- Painful eyes and/or altered vision
- Skin rash
For a more detailed look at mold symptoms, check out my post on mold illness and CIRS.
People with mold illness or CIRS often have a sixth sense for smelling molds. Dank, musty smells are the hallmark signs for mold in your house. If you regularly experience a worsening of your symptoms at home and smell a musty odor, it’s time to perform laboratory testing.
3. Visible mold growth
Do not rely on your vision as the only way to diagnose mold in your house. That’s because mold tends to collect in hidden areas. But if you have symptoms, take a good look around your home for mold. Keep an eye on:
- Taps/faucets – ensure they are not leaking
- Your bathroom shower and tiles
- Window sills
- Change the filters in your HVAC system regularly (every 3 months)
But remember: just because you can’t see any mold does not mean your home is mold-free.
4. Water leaks and/or past flooding
Mold needs a source of water or moisture to grow. For example, a leaky pipe under your sink is a perfect place for mold to thrive – it’s dark, damp, and temperate. The same goes for buildings/homes following a flood.
In 2013, we experienced a massive flood in my home town. Nearly all of the downtown core was underwater. I cringe when I think about the amount of mold that’s likely growing in the homes and buildings following that flood.
If your home does flood, proper moisture remediation will be essential. You will also need to continue testing your home for mold after remediation. If your symptoms start after a flood, you have a reliable indicator that is pointing towards mold in your house.
Ok, these are the preliminary indications that may indicate there’s mold in your house. If you’re symptomatic and you experience any of these four signs, it’s time to move to laboratory testing.
Test your house for mold – the ERMI mold test and HERSTMI 2 mold test
There are currently two laboratory tests used to measure mold levels in your home: the ERMI mold test and HERSTMI2 mold test. Each of these tests approach mold testing differently. I’ll explain the pros/cons of each and give my recommendations on the best way to test your house for mold.
ERMI Mold Testing
The ERMI (Environmental Relative Moldiness Index) test is a reliable, straightforward test to objectively determine the levels of mold in your home. It was developed by the United States Environmental Protection Authority (USEPA).
In order to understand what is a normal amount of mold in a home, the USEPA compared levels in over one thousand different homes across the United States. These homes were ranked from lowest to highest levels of relative moldiness.
The ERMI mold test detects 36 different species of mold. There are:
|Group 1: Water Damage Molds||Group 2: Common Indoor Molds|
|1) Aspergillus flavus/oryzae,||27) Acremonium strictum|
|2) Aspergillus fumigatus||28) Alternaria alternata|
|3) Aspergillus niger||29) Aspergillus ustus|
|4) Aspergillus ochraceus||30) Cladosporium cladosporioides1|
|5) Aspergillus penicillioides||31) Cladosporium cladosporioides2|
|6) Aspergillus restrictus||32) Cladosporium herbarum|
|7) Aspergillus sclerotiorum||33) Epicoccum nigrum|
|8) Aspergillus sydowii||34) Mucor amphibiorum|
|9) Aspergillus unguis||35) Penicillium chrysogenum|
|10) Aspergullus versicolor||36) Rhizopus stolonifer|
|11) Aureobasidium pullulans|
|12) Chaetomium globosum|
|14) Eurotium (Asp.) amstelodami|
|15) Paecilomyces variotii|
|16) Penicillium brevicompactum|
|17) Penicillium corylophilum|
|18) Penicillium crustosum|
|19) Penicillium purpurogenum|
|20) Penicillium Spinulosum|
|21) Penicillium variabile|
|22) Scopulariopsis brevicaulis/fusca|
|23) Scopulariopsis chartarum|
|24) Stachybotrys chartarum|
|26) Wallemia sebi|
You will receive an ERMI score that will place your home in four different quadrants based on the amount and types of mold species present:
1st Quartile (Q1)
This makes up approximately 25% of all homes. The ERMI score/value for Q1 is any value from -10 up to -4. Homes with this score have very low levels of mold.
2nd Quartile (Q2)
This makes up approximately 25% of homes. The ERMI score/value for Q2 is any value from -4 up to 0. Homes with this score have low to medium levels of mold.
3rd Quartile (Q3)
This makes up approximately 25% of homes. The ERMI score/value for Q3 is any value from 0 up to 5. Homes with this score have high levels of mold.
4th Quartile (Q4)
This makes up approximately 25% of homes. The ERMI score/value for Q3 is any value from 5 up to 20. Homes with this score have very high levels of mold.
There are homes whose ERMI score is even greater than 20. As you can well imagine, these homes have incredibly high levels of mold.
There are two methods to properly collect a sample of molds from your home for an ERMI test.
- With a vacuum cleaner. A special nozzle is fitted to your vacuum cleaner and allowed a sample of dust to be taken by masking off a 900 x 1800mm rectangle in your living room and a similar area in the master bedroom. They are each vacuumed for 5 minutes to obtain a composite sample. This method is ideal for carpeted homes. Mold species love to collect within the carpet’s fibers.
- With a Swiffer cloth. This method is ideal for homes with hardwood or tiled floors. To obtain a proper sample, you’ll want to collect from areas where dust/mold tends to settle. These areas include baseboards, window sills, and the tops of ceiling fans.
HERTSMI 2 mold test
The HERTSMI 2 (Health Effects Roster of Type-Specific Formers of Mycotoxins and Inflammagens – 2nd Version) mold test does not measure as many mold species as the ERMI mold test. HERTSMI 2 test looks for the big 5 mold species. These are:
- Aspergilus Penicilloides
- Aspergillus Versicolor
- Chaetomium Globosum
- Stachybotrys Chartarum
- Wallemia Sebi
Scoring for the HERTSMI 2 mold test is as follows:
<10 – The home/building is safe for someone with a mold allergy or CIRS (Chronic Inflammatory Response Syndrome) to live in.
11-15 – This home/building is borderline high. Consider additional mold remediation before living here.
>15 – This home/building is dangerous for someone with a mold allergy or CIRS. Do not live in a home/building with a HERTSMI 2 score greater than fifteen.
How to properly remove mold from your house
After learning that your home/building has a mold problem the next step is to identify the source of mold and remove it. As I mentioned earlier, mold needs moisture. Looking for mold should be focused on areas where condensate and moisture can get trapped. Common areas include HVAC systems, underneath sinks, and bathrooms. Know that mold/moisture could also be growing behind your walls.
It only takes 48 hours of water/moisture exposure for mold to start growing.
If you find mold in your home, the process of removing it is long and arduous. Since mold spores travel through the air, it is not uncommon to have to replace clothing, furniture, and the physical building materials in the area where the mold growth occurred. This can include drywall, insulation, baseboards, and windows.
Then there’s the difference between mold removal and mold remediation.
Mold removal is just that – the removal of mold. This often involves scrubbing/scraping the mold off of the area it is adhered to and replacing the damaged building materials. It’s an essential part of the process but it doesn’t result in mold remediation.
Mold spores are microscopic – you won’t be able to see them with your eyes. If you don’t deal with mold spores, your mold problem will likely continue – even after you’ve removed all the visible molds.
To properly remediate mold, you’ll need large High-Efficiency Particulate Air (HEPA) filters running in your home. These filters will trap mold spores in the air.
Additionally, you may need to control the humidity level inside your home. If the relative humidity of your home is more than 45%, consider investing in a dehumidifier. Controlling humidity levels will help to ensure mold spores don’t have a place to grow.
After the mold in your house has been removed and remediated, perform a HERTSMI 2 test to determine if it is now safe for you to live there. If your HERTSMI 2 test is above 10, you need to do more remediation work. I strongly encourage you to use mold removal professionals, not general contractors/handymen. Much like healing from a mold allergy or CIRS, proper remediation/removal of mold is a complicated, multi-step process. If it’s not done correctly, you’ll experience a never-ending battle with mold.
Did you know Flourish Clinic specializes in the treatment of CIRS or mold sickness?
Ok, now you know how to determine if there’s mold in your house and what to do if there is!
Now, I want to hear from you!
How did you identify mold in your house?
What steps did you take to remove it?
Leave your answers in the comments section below!
Afton Jackson says
It made a lot of sense to read the part of your article that lists past floods and water leaks as a sign of mold growth in a house. The fact that we’ve been sneezing a lot more ever since we had that faucet leak a couple of weeks ago is convincing me even more that we still have a lot of work to do to clean up our house before the holidays begin. With that in mind, I’ll play it safe and look for any mold removal companies in our area that can assist us.
Kate Hansen says
It’s good to know that have headaches and runny nose are symptoms of mold. I have been experiencing these symptoms. I’ll have to look into hiring a mold remediation service.