How To Know If You Have Mold In Your House

Mark Volmer
Jul 19 · 8 min read

Using just your nose and eyes is not a reliable way to determine whether or not you have mold in your house.

Mold hides in areas you cannot see or smell!

You need to utilize specialized testing to determine if your home is making you sick.

The first step in overcoming a mold allergy or chronic inflammatory response syndrome is removing yourself from the source of exposure. It’s as simple and complicated as that. The challenge is accurately determining if your house has mold.

What you need to know about moldy homes

I want to be crystal clear — using your eyes and nose is not a 100% reliable way to determine if your home has mold. Mold growth often occurs out of site in ventilation ducts, attics, or crawl spaces. Often, these are not areas that undergo a visual inspection.

Laboratory testing is by far the most effective means in determining if your home is moldy.

The steps I list below are a preliminary screening tool. If you don’t have mold allergy symptoms and you cannot see nor smell any sources of water/mold, you probably don’t need to bother with laboratory testing. But if you’re symptomatic, do not skip lab testing your home. It needs to be done. I go in to the specifics on laboratory testing at the bottom of this post.

Signs that there’s mold growth in your house

1. Your symptoms

A strange array of symptoms is perhaps the most obvious sign that there’s mold in your home. The symptoms of mold illness are vast and non-specific. Often, mold illness symptoms will be diagnosed as strange conditions such as fibromyalgia, chronic fatigue syndrome or irritable bowel syndrome (IBS).

Some of the more general (though less severe) symptoms of mold in your home include:

  • Headaches
  • Stuffy or runny nose (rhinitis)
  • Excessive sneezing
  • Painful eyes and/or altered vision

For a more detailed look at all the symptoms associated with mold, check out my post on mold illness and chronic inflammatory response syndrome. If your symptoms improve when you leave a particular building or worsen when you re-enter that same building, this is another sign that there may be mold in your home.

2. Odors

Those dealing with mold illness or chronic inflammatory response syndrome will often possess a sixth sense for smelling molds. Dank, musty smells are the hallmark signs for mold in your home. If you regularly experience a worsening of your symptoms at home combined with a musty odor, it’s time to perform laboratory testing.

3. Visible mold growth

Do not rely on your vision to detect mold. As I stated earlier, mold tends to collect in areas outside of your line of sight. If you’re symptomatic, be vigilant in visually checking your home for mold.

Keep a close eye on taps/faucets — ensure they are not leaking. Monitor your bathroom shower and tiles for mold growth regularly. Window sills are another area where mold can collect. Change the filters in your HVAC system regularly (every 3 months). Just remember, just because you can’t see any mold does not indicate your home if free from mold.

4. Water leaks and/or past flooding

Mold needs a source of water/moisture in order to grow. A leaky pipe under your sink is a perfect place for mold to thrive — it’s dark, damp, and temperate. 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 under water. 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. So will testing your home for mold multiple times after remediation. Should your symptoms start after a flood, you have a reliable indicator that is pointing towards mold in your home.

Ok, these are the preliminary indications that may mold in your house. If you’re symptomatic and you experience any of the above four signs, it’s time to move to laboratory testing.

How to properly test your house for mold

At the time of this writing, there are two laboratory tests used to measure mold levels in your home. Each takes a different approach to their testing methodology. I’ll explain the pros/cons of each and give my recommendations on the best way to test your house for mold.

ERMI Testing

The Environmental Relative Moldiness Index or ERMI test was developed by the United States Environmental Protection Authority (USEPA). The ERMI test is a reliable, straightforward test to objectively determine the levels of mold(s) in your home. In order to understand what is a “normal” level of mold in a home, the USEPA compared levels in over one thousand different homes across the United States. (1) Homes were ranked from lowest to highest levels of relative moldiness.

The ERMI test is able to detect thirty-six different species of mold. These include: (2)

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 13) Cladosporiumsphaerospermum 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 25) Trichodermaviride 26) Wallemia sebi

The results of your ERMI test 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 great 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. The first is via 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.

The second means of collecting a sample for the ERMI test is via 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 testing

HERTSMI 2 stand for Health Effects Roster of Type Specific Formers of Mycotoxins and Inflammagens — 2nd Version. The HERTSMI 2 test does not measure as many mold species as the ERMI test. HERTSMI 2 testing measures what are known as “the big 5” mold species. These are:

  • Aspergilus Penicilloides
  • Aspergillus Versicolor
  • Chaetomium Globosum
  • Stachybotrys Chartarum
  • Wallemia Sebi

Scoring for the HERTSMI 2 test is as follows: (3)

<10 — The home/building is safe for one with mold allergy or 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 one with mold allergy or chronic inflammatory response syndrome. It is not recommended to live in a home/building with a HERTSMI 2 score greater than fifteen.

How to remove mold properly

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/or moisture can get trapped. Common areas include HVAC systems, underneath sinks, and bathrooms. Know that mold/moisture could also be growing behind your walls.

48 hours of water/moisture exposure is all it takes for mold to start growing.

If you find that your home is a source of mold, 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 home/building 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 anything above 10, more remediation work needs to be done. 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.

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!

Do you need help improving your fatigue?

Originally published at Fatigue to Flourish.

Mark Volmer

Written by

I help those with fatigue naturally reclaim their energy and share their gifts with the world.

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