Your Superpower

Grow Your Knowledge Of Buildings

Mold is easy to understand. It needs moisture and food to thrive.


Buildings are largely food for mold — and increasingly made of processed fibers and materials. Dust feeds mold, as well.


When moisture intrudes into buildings, mold is the outcome — always.

All it takes is a leak, clogged drain, or high humidity for modern homes to grow mold.

Poor architectural design can lead to moisture intrusion. Water and humidity are ubiquitous in and around buildings. Moisture must be controlled at every nook and cranny of a building — and outside it.

For older homes, it only takes the passage of time for moisture intrusion to occur — given enough time, a leak will happen somewhere. Proper maintenance can prevent a leak from developing mold, but only when occupants are immediately aware of the leak.

Confusion disappears when we understand how buildings work.

A calm, clear mind is best. Whatever happens, you can handle it.


Explore The Building

Become A DIY Building Inspector

Inspect every inch of your home — looking for signs of moisture or water intrusion.

You don’t need to have all the answers now, and being unsure about something is okay.

First, learn the process of inspection.


Where Water Intrudes

As you look at a building, use your imagination: How does water interact with this structure?

  • Where does it land? Where does it flow?
  • How might moisture find its way into the house?

It can be surprising to realize how easily water can find its way into buildings.


Windows need a tight seal. Otherwise they can let water inside the walls.


Roofs must be watertight. Even slightly loose shingles, nails, and screws let water into the building.

Foundation lines

Water can collect next buildings when proper drainage is lacking. Moisture will find a way inside if allowed to linger.

Water should always be directed far away from a building, and not be allowed to sink underneath the foundation.

This drainage water almost certainly found its way under the foundation of the house, potentially destabilizing the slab or humidifying the crawl space.

Image result for water on side of house

Gutters should empty onto a splash block, not the ground. A splash block distributes water further fromthe house.

Plumbing Leaks

The more “wet walls” (walls with plumbing inside) in a building, the more likely a leak will develop inside one. More pipes –> more opportunity for a problem.

Therefore: monitor sinks, showers, and toilets regularly. Look for any signs of leaks.

Leak under a sink.

Appliances That Use Water

Many, many appliances utilize water in their operations. Any of these machines can become a major problem via leaks or clogged drainage lines.

  • Refrigerators
  • Washing Machines
  • Dishwashers
  • HVAC Systems
  • Freezers
  • Garbage Disposals
  • Toilets
  • Sinks
  • Showers
  • Water Heaters
  • Humidifiers/Dehumidiers
Washing machine leak.

HVAC System

Condensation is created whenever air is rapidly cooled.

This is an invaluable, cheap tool.

This condensation goes into a drain, which can be clogged. The evaporator coils can get moldy, too.

Pay special attention to your HVAC System.  

Get to know it. Compare it to how other buildings’ systems are.  Smell the air that comes from vents and look inside the unit.  Observe the filters and the coils.  Notice thermostat settings. Become aware of its health status.

Buy a humidity meter (cheap on Amazon).


Inspect The Whole Building

As you walk through the building, keep imagining how water might arrive at any location inside the house.

Explore every room at close proximity. Look in corners, where walls meet the floor and ceiling, and inside closets and cabinets.

Don’t forget that humidity above 60% represents enough moisture to substantially feed mold.

Rooms & Spaces

  • All rooms
  • All closets
  • Corners
  • Bathrooms
  • Basements
  • Garages
  • Attic

Nooks & Crannies

  • Cabinets
  • Electrical outlets (sniff)
  • Drains
  • Under stairwells


  • Entire exterior of the building
  • Roof and gutter systems
  • Close to the house/Foundation lines

These complete inspections should be routine — performed at least monthly.

Use Your Nose

A moldy smell may be 90% of the information needed when determining how healthy a building is.

Your nose can also help you locate mold in a room.

If there’s a musty smell, there’s almost certainly mold growth somewhere.

Mold isn’t always visible — it’s often tucked away inside walls and ducts. But if you can smell it, it’s there.

Hibernating mold can still release toxic fumes and spores long after it has dried up.

It’s possible and common to smell mold that hasn’t been actively growing in some time — but still affects the health of the home.

Trust your nose. It could be the best tool available. 

Weak Nose?

Rudy Gobert, NBA player, ten days after being infected by COVID-19.

Anosmia is the scientific name for a weakened sense of smell.

What causes anosmia?

  • Infections
  • Allergies
  • Diseases involving organ injury and energy deficiency
  • (Smoking)

How does mold affects the body? In terms of allergies and infection. Mold adversely affects organ function, nutritional absorption, and can lead to chronic fatigue syndrome.

Mold spores and toxins subtly work against bodily function. Losing the sense of smell is one sign of this happening.

Image result for mold in wall
Mold growing in and behind cabinetry.

Use Your Eyes

Mold is often unseen — hiding inside appliances, walls, attics, closets, flooring, & cabinets.

On the other hand, water moves — it soaks through materials. If. a leak gets bad enough, its chances of becoming visible rise.

Visible Mold

  • Around air vents
  • Molding, corners, wallpaper
  • Flooring
  • Surfaces
  • Water damage
  • Drains
  • Showers
  • Washing machines

Hidden Mold

When mold is often not easily seen, it can escape our attention and grow exponentially into a massive problem.  

Therefore, to successfully stop mold, the location and extent of moisture intrusion must always be identified.  

Humidity enables mold growth — especially in crawl spaces and garages — usually made worse by poor airflow (trapped air).  In trapped spaces, humidity enters a space, moisture in the air rises, and then can’t leave.

Too, summer climates often have humidity in the 70%-90% range. Air doesn’t even need to be trapped to encourage mold growth when humidity is this high.

Related image
Mold growth in a crawlspace.

Observe all of these spaces. Look with your eyes for any sign of fungal growth. Feel the air and measure it with a hygrometer. Search for musty smells.

“Crawl space air will eventually be indoor air.”

– Eric Davis, Building Biologist

Finding one area of mold doesn’t mean the job is over. There could be more.  


Extra Tools

Infrared Cameras — Can See Moisture

Infrared Cameras can see surface temperature.  

If water is present in a wall, the wall camera sees less heat (infrared light) coming off of the wall. This is because water is always a heat sink.

The “heat signature” is gone, with the water soaking up all heat.

Seeing inside the walls via Infrared Camera is a much better first option than cutting holes in walls.

You Can Purchase an Infrared Camera

Cheaper models run around $75-$350.  

Higher-end models are in the thousands.  Higher-end models will be needed for precise measurements of temperatures inside walls, which can be an extremely handy tool.  The cheaper models are nevertheless quite valuable to keep track of your home and other buildings. You can bring in the big guns — a Building Biologist — later if your findings are troubling.

Moisture Meter

These meters are cheap and simple to use. Simply hold up to the wall and check the moisture content of this area of the wall.

General Tools MMD4E Digital Moisture Meter


Certified Building Biologists

Your Best Guide For Home Inspection

A certified Building Biologist will have rigorous training, high-quality instruments (including an infrared camera) and will be able to help guide you through the process of determining causes, solutions and severity of issues.  

Professional-grade air quality tests can be performed (of much higher value than store-bought tests and can include other contaminants besides mold), non-visible moisture and leaks can be detected, and even EMF testing (which can be incredibly important).

Building Biologists Don’t Do The Remediation

While a Building Biologist may appear to be highly adept at solving moisture issues, it is construction crews who do the work on your house. You need to find a contractor who understands how to remediate and remove harmful mycotoxins and spores without spreading them.  

A remediation job can be a difficult, complex, and expensive process. Trust yourself, how you feel, and stay on top of the process.

Micro-manage it, even — do not feel like you’re bothering the contractor. Be upfront about what you need, get a signed contract for the work, and monitor the work yourself. Be selective about who you hire.


Mold Testing


Get a cheaper HERTSMI test right away — if you want.  

  • Only tests for 5 molds.
  • Cost: ~$190


More extensive and expensive.

  • Tests for 36 molds.
  • Cost: ~$290

Air Test

Woe-fully incomplete test.

  • This only gives you a tiny snapshot of what’s happening in your building.
  • Likely to seriously underestimate any mold issues.

Petri Dish

Nearly worthless.

You can buy these cheap kits at Home Depot.

  • These tell you very little.
  • If mold grows incredibly fast, this might indicate a severe problem.
  • Otherwise, this test is of little scientific value.

Order a HERTSMI or ERMI test –> here.

Mold Tests Are Hardly Perfect

No test — even the best ones (ERMI, HERTSMI) is conclusive of anything.

There will always be room for error with any scientific test. Further, tests only show a snapshot in time.

Testing surfaces only shows what was on that specific surface on that day.  It’s possible for some spores to be airborne, or follow airflow patterns to a different surface in a room. It’s also possible for cleaning to interfere with surface tests.

Testing the air only reveals the contents of the air during the test period. Varying humidity levels can skew air test results. Air tests won’t demonstrate what is on surfaces

The Limits Of Testing
  • Neither test is likely to include spores resting behind the toilet or inside walls.
  • Tests don’t identify the location. or size of mold growth. Tests likely won’t reveal problems that are in their infancy.
  • It’s also possible for mold’s toxic odors to seep through the walls while the spores remain behind walls, hiding from any mold test.

Mold Expert, Mike Schrantz

Mike Schrantz owns and operates Environmental Analytics, an environmental consulting firm. Here’s a quote I found from him in an interview with Chris Kresser.

“It’s hard to ignore that testing that by itself doesn’t always cut it. [The] visual [component] is, in some parts of this, just as important, dare I say slightly more important, than data itself.”

Mike Schrantz

Schrantz is a very knowledgeable, data-driven expert. He is performing a service, for a fee, and he doesn’t want to depend on guesswork — so that lends itself to testing, reports and data. “I think, maybe…” doesn’t work so well when you’re charging people lots of money and guaranteeing results.

That said, even a super data-driven expert like Schrantz says that focused, motivated, curious observation is (at least to some extent) MORE IMPORTANT than testing.

Do tests have a place? Sure. Absolutely. More information is always good, as long as you understand that mold testing results are simply a snapshot of one place at one point in time.

But the best information comes from you. Walking around, poking around, looking with your eyes, smelling with your nose — using your awareness.

The Chris Kresser Mold Story

The internet-famous acupuncturist and health blogger, Chris Kresser, bought a 1920’s house in the (very-humid) Bay Area a few years ago.

They suspected mold and decided to test for it.

Chris hired Mike Schrantz, who flew in (multiple times) from Arizona. He did extensive testing, but the tests didn’t show much mold, only slightly elevated spore counts. They wanted to explore more — to make sure the house was safe — so they cut holes into walls and removed some sections of walls. Testing still didn’t show much.

It was only a few rainy days later that Chris noticed one of his walls was wet to the touch (and bulging a little) next to a window. That’s a MAJOR sign! So they tore out the wall and found the window had been leaking.

Inside the wall, they noticed mold growing above the window — which indicated moisture above the window. Looking higher up, they found a failed gutter system that was pouring water into the walls — and mold was everywhere.

Finally — after all moldy materials had been removed and the area scrubbed clean, they retested… and failed the ERMI test.

You don’t just inspect once and that’s the end of it.

Chris Kresser

On a blind hunch, they guessed the cleaning crew had not cleaned very well — simply because the ERMI test employee saw more dust on the floors than he’d expect after a thorough cleaning.

So they cleaned more thoroughly and tested again, and their new ERMI score “passed.” (Now, even this latest ERMI score doesn’t show what spore counts look like after, say, 12 months. It’s possible they didn’t fix the problem and more water intrusion will happen soon. It’s also possible the mold VOC’s permeated the house to an unhealthy level, even if mold growth has been entirely stopped).

Said Kresser: “In all of the testing that we did, the testing just pointed to a problem, but the place that ended up being the most significant issue was something that was not identified with any of the previous testing and that we actually found by good old fashioned visual observation.”

Don’t Obsess Over Tests

It’s easy to become obsessed with testing mold counts.  

Don’t. Instead, trust your nose and how you feel and use tests as an adjunct.  If the air doesn’t smell fresh, that’s 50% of what you need to know.  If you feel poorly, that’s almost the other 50%. Tests aren’t always reliable, and no two people will react identically to the same result, anyway.

If you have the money to perform tests, yes. Do multiple. If you’re remediating, yes. Do many rounds of tests.

But don’t trust them. Don’t wait around for months wondering, waiting, thinking someone is going to swoop in and tell you what to do. Instead, be vigilant. Be curious. Get to know your building. Inspect it frequently. Understand it. Take steps to improve your health now.

These tests aren’t perfect, and sometimes under- or over-report the severity of mold present in a various parts of a building.

Greg Muske’s Experience

Greg Muske of is a wonderful resource for the mold community, and he is very pro-testing. He is like many mold advocates, experts, and doctors — focusing a large majority of their energy on mold avoidance.

“My house is a perfect case in point. We’ve now spent over 2 years and $8,000 doing all of the above mentioned tests numerous times (7 ERMI, 40+ spore traps, a couple dozen Petri dishes, 2 VOC tests, and one mold-dog) in an effort to find out if the new home I built has mold issues. We’d do a round of tests. I’d tear into the house even more. Nothing would be found. I’d then go back and re-evaluate the test method before testing in another way. Round and round and round we went. None of the tests seemed definitive. Talking with four different professional inspectors often left me with more questions than answers.”

“You’d think that with this arsenal of tests along with the expertise of a mold inspector that you could tell if a building is moldy or not. Unfortunately, sometimes it’s not always so straight forward.”

Greg Muske

If you need to take action — even major action — mold testing can help confirm what you’ve already realized via your own inspection and intuition. This website is designed to help you get there: fully aware, equipped, and ready to act.

“Mike, I’ve heard you say it, I’ve heard other people say — if you smell a mildewy, moldy smell, that’s enough, right?”

Chris Kresser (in conversation with Mike Schrantz)

Stop All Water Intrusion

A mold test won’t show a water leak. Moisture intrusion must be noticed by human occupants.

This means homeowners must be fully aware of all potential sources of water accumulation — whether from pipe leaks, rain fall, flooding, or humidity.

Active Leaks Must Be Stopped

Identify all areas of high moisture. Make the call, or do it yourself. Get the leak fixed immediately!

If an area is newly wet, purchase fans and dehumidifiers to quickly dry the area. Heat lamps are also an option (be careful, they’re super hot!).

Look For High Humidity

High humidity is also water intrusion. Therefore, identify any areas with high humidity or trapped air. If you pay attention, you can feel how humid air is.

Put a hygrometer in various places around the house. You want indoor humidity to be lower than 60%. Under 50% is even better.

If humidity is above 60%, chances rise that mold could be in the area.

Look For Any Sign Of Mold Growth

Even small amounts of water intrusion can cause issues.

Don’t just look for visible mold — it’s often difficult to see — look for signs that water is, or has been, present : bubbling, warping, smells, and other signs of

Find and stop leaks and moisture intrusion immediately — either by yourself or with professional help. It only takes 24 hours for mold to sprout.



You’ve explored your home and grown awareness. Now, take stock of your current situation — what’s going on?

All Clear?

All Clear?

Now, you need to stay vigilant — and prevent mold growth in your space.

Small Problem?

Small Problem?

Can you handle this yourself?

Severe Problems?

Severe Problems?

Mold has spread onto porous building surfaces that must be removed professionally.


Clean With A Plan

Have a plan before you start. 

Think of all materials needed, how you’ll dispose of ruined objects and towels, and how you’ll ensure spores won’t be spread.

Tread gently and carefully as you fact-find and purge contaminated items.

When you’re ready to clean, do so precisely and quickly.

First, Remove Exposed Items

Throw away all questionable objects that were in the direct vicinity of the mold.  

This includes plastic, wood, and cloth materials.

Mold can attach to plastic.  Get rid of any plastic that’s been exposed to mold.

The only items that should be saved are expensive or meaningful items that have non-porous surfaces. Have a trash bag handy that you can quickly tie-up and remove from the home.

Then, Clean Up The Area

Wipe mold up very carefully and slowly, so it isn’t disturbed and releases fewer spores.

Go over it many times, and then saturate with vinegar extremely well. To greater reduce the odds of mold returning, wipe down the area every day for a week, and then weekly going forward.

Look to see if there’s a chance the mold has spread inside walls, cracks between finishes, or mechanisms.

Mold will follow moisture — if there is any — inside the walls/mechanisms.

Have a trash can to immediately put dirty and contaminated wipes in. Be mindful of having mold on your hands. Close the trash bag immediately when done, wash hands, and remove the bag from the house.

Wipe down everything in the room as much as possible. Clean sheets if in a bedroom. Change clothes and shower off.

The Best Disinfectant Products

Benefect Decon 30
Buying in bulk saves money.
Vital Oxide
Just use an empty spray bottle.
These Are Both Incredible Products
  • Both of these products kill 99.99% of all microbes — true hospital-grade disinfectants.
  • Both are safe to clean food surfaces with. They claim you don’t even have to rinse a food surface before using it to prepare food.

The Best Product To Prevent More Mold

Concrobium Mold Control

Other Options

Cleaning Vinegar — add Essential Oils

Mix in a spray bottle.  Vinegar doesn’t have to be diluted.  Put as many drops of Tea Tree oil (or other oil) as you like — the only concern is the cost of the oil.

Other essential oils are quite antiseptic — Thieves oil, clove oil, etc. 

Thieves Blend

Tea Tree Oil

You can substitute Borax (in water) for the vinegar, too — it’s highly killing and safe. 

Hydrogen peroxide kills mold — be careful not to get it in your eyes.

Bleach and other harsh chemicals may agitate mold and cause them to release more mycotoxins. If you’re worried about this, use something else.

Be Mentally Ready

Drying a small, 2-Day old leak under new cabinetry with a heat lamp.  

When you’ve devised a plan, then make sure you’re ready to tackle the project.

If you’re not — that’s okay.  Take some time, gather your thoughts, and proceed when ready.

For many folks, mold exposure cause mental or emotional instability. 

If this applies to you, be prepared for the challenge — and be ready to get some fresh air afterward.

Follow smart steps to keep spores contained, discover the extent of the water intrusion, and remove all compromised materials.

Ozone & UV

After cleaning, ozone & UV light can make areas hostile to mold.

Both are best suited for prevention and once a moldy area has been cleaned, that’s precisely what’s needed.

Ozone the area frequently over the next several weeks, and continue 3-4x/month indefinitely.

Was Cleaning Enough?

Hard, non-porous surfaces are cleanable.

Cloth, carpet, wood, and other porous surfaces are not. Porous surfaces include:

  • Bare wood
  • Plastic — (mold seems to be able to colonize in plastic.)
  • Fabric
  • Finished wood (if exposed for long enough. Polyurethane finish is made of plastic).

If the mold spread to building materials, you’ll need to remediate professionally.

Should You Remediate?

If the problem was not contained in this small area and/or was not fully cleaned — or has spread, affecting other areas of the house — you’ll need to remediate.

In fact, professional remediation is always necessary if you suspect the area or building materials will continue to harbor mold growth and spores.  

If an area will continue to experience high humidity, you’ll need to remediate that issue, too. The mold will come back in high humidity (above 60%).

A Medium-Sized Problem That Probably Should Have Been Remediated

Workplaces are notorious for skimping on building health.

I found this under a sink at a former job.  A cup had been placed under a leaky sink to catch drips.  When it filled, a pan was placed under the cup.  The water then spilled out of the pan, soaking the cabinetry. Of course — black mold was the result.
Every item under this sink was carefully thrown away, the area scrubbed and bleached, and then ozoned for several days.  It is highly likely that spores still remain in this cabinetry (hiding in crevices) and in the vicinity, even after much effort to clean.


How Severe Is The Growth?

The problem is severe when these factors are present:

  • Mold has grown onto porous construction materials.

…you will need professional help.

Too Bad To Remediate?

If it’s bad enough you may be best off moving to a new home. Remediation can be ineffective and extremely costly.

Your health matters most, here. How likely is full removal of all mold growth, spores, & VOC’s?

Factors To Consider

  • How long has this house been moldy?
  • Was this contained
  • Did it spread to the whole house? 
  • Was there traffic through the contaminated area(s)?
  • Did it spread to the HVAC system?
  • Did tests show high spore counts?
  • Did tests show particularly dangerous mold species?

The Path Forward

Trust Yourself First

(&, if needed, A Highly Skilled Building Biologist)

If you suspect mold is actually affecting your health, don’t rest until you find someone who can identify all of your home’s problems — and help you truly solve them.    

The person you need might be you — if you educate yourself well.

Will Remediation Work?

Remediation often falls short.

Sometimes, not all moldy materials from a house are removed. Many companies fail to prevent the spread of mold spores around the house.

How well you feel in a house after remediation will depend on 1) how sick you’ve already become and 2) the quality of the remediation job. 

You may be too sick to tolerate most remediation jobs.

Beware Low-Ball Quotes

Conventional mold remediator employees may inform you that you “don’t have a very big problem.” 

This conclusion is often reached after only a superficial visual examination.  

They may quote you a job and price they think you’ll be more likely to agree to pay — instead of the job and price that would thoroughly remedy the problem.

Remediation & Lawsuits = Stress

Unfortunately, leaving a home and belongings behind is often the safest, easiest, and most productive solution available.

Leaving is also often more cost-effective.

Rather than remodel and remediate — which is spending tens of thousands on improvements that will never be recouped upon resale of the house — the house can be sold “as is.”

Sadly, most buyers will not care, even when explicitly told what’s happening in the home.

The alternative might be tens of thousands lost in multiple failed remediations, followed by multiple subsequent moves to multiple homes, bringing the mold to the new homes (cross-contamination).

By law, mold issues must be disclosed to potential buyers. Many simply won’t care that there’s a problem.


If You Remediate

Remediation Is Risky

Remediation happens a lot, because indoor mold is common. There are remediation companies in most areas.

However, not all remediation is successful. Sadly, there are as many bad remediation stories as happy endings.


This is because big money is involved, the variables can be complex, companies are not trustworthy, and your sensitivity may leave you with exacting standards that can’t be met by many businesses.

“Mold experts” in your area may not be experts in mold illness — and their primary interest is to sell you on their service, not you.

Awareness Is Your Superpower

If you suspect a home “isn’t quite right” — don’t underestimate your own ability to poke around.  

Explore buildings. The more you learn about the “built environment” and how water interacts with it, the better off your health will be.

This completes Awareness.
To continue, select Clean.

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