Instructor Ed Jones has over 30 years of experience in theindustry, has the title of MasterWater Restorer, is an Institute ofInspection Cleaning andRestoration Certification (IICRC)-approved instructor, and hasserved on the S500-2021consensus body committee todevelop the most recent standard.
When there is water damage in someone’s home or business, it may not seem like a big emergency as long as you get the water turned off, vacuum or mop up the water, and put a fan on it.
Unfortunately, most people do not understand that water follows the path of least resistance and goes down due to gravity. It can easily get behind or underneath materials where you cannot see it.
Add to that the fact that the longer water sits in contact with building materials, like drywall and wood, the more opportunity microscopic microorganisms have to start growing.
The microorganisms I am talking about include:
They all depend on moisture to grow, multiply, and thrive.
Fungus, which I call the “fun-guys and fun-gals,” needs five things to grow:
The optimum temperature range is typically 68 to 86 degrees Fahrenheit.
Organic food sources may include:
Some xerophilic molds, such as aspergillus and penicillium, do not need much moisture to grow. These are typically some of the first “fun-guys and fun-gals” to show up.
Other species of mold, such as stachybotrys, need a lot of moisture to grow and generally do not show up for weeks. They are often an indicator of chronic water damage.
Stachybotrys became known as the “black toxic mold” that many people feared because of public attention around black mold and health concerns. To this day, many people are still very scared of mold.
People typically fear what they do not understand.
Examples include:
To reassure people, we need to educate them on how mold occurs and what to do to prevent it from growing in the first place.
The best way to stop mold from growing inside buildings is to start mitigation as quickly as possible and never give it a chance to begin growing.
At our IICRC-approved flood house, called the Disaster Recovery Learning Lab, or DRLL, on the Clark State campus in Springfield, Ohio, we intentionally get a home wet every month and dry it out in 3 to 5 days with no mold.
In addition, we build a “mold incubator” by putting normal building materials into a plastic bin, soaking them with water, and leaving them at room temperature.
These materials may include:
We then record how quickly mold can become visible to the naked eye inside the incubator.
In our testing, which has been repeated dozens of times, it is typically 5 to 6 days before mold becomes visible to the naked eye on wet materials.
This is inside a mold incubator where we have optimum conditions for mold to grow.
Inside someone’s home, especially if there is a functional HVAC system, it would usually take much longer.
You may have heard that mold can show up on wet materials inside buildings after only a day or two, or 24 to 48 hours. However, when you better understand how mold grows, that timeframe is usually when the mold spore is just beginning to grow at a microscopic level.
You will not be able to see it at the 24-to-48-hour point because it takes that long for the cell wall of the mold spore to soften and send out an exploratory root called a hyphae, looking for an organic food source.
A mold spore is extremely small, usually around 3 to 10 microns in size. For comparison, the width of a normal human hair is around 75 microns.
Mold spores can sit dormant on surfaces in your home and float in the air because mold is ubiquitous on this planet.
Mold is the third-largest group of living matter on earth, behind plants and bacteria.
Mold is not an issue unless it has a chance to grow and proliferate inside a structure. It needs moisture to make that happen.
In other words, mold needs an organic food source and must be wet enough, long enough to begin growing.
Different species of mold have different water activity levels.
Water activity is the equilibrium relative humidity, also known as ERH, of the air right at the surface of an organic material that would allow mold to begin growing.
Generally, xerophilic molds, which need the least amount of moisture, can start to grow on an organic food source around 70% to 75% ERH.
Once the mold spore finds a wet organic food source, it sends out more roots called mycelium and starts feeding and reproducing.
All of that takes days.
That is why, under optimum conditions in our mold incubator, we typically do not see visible mold without a microscope until about 5 to 6 days.
All of this is to say that we have about one week of materials being wet before we risk mold showing up.
In a normal home with a functional HVAC system, it may be closer to two weeks. However, because we do not always know exactly when the water loss started, it is best to err on the side of caution.
A professional, certified restorer should get to the loss location as soon as possible because the property may already be on the cusp of mold growth beginning.
Remember, destructive mold growth can begin to occur on wood at 20% moisture content or above.
Moisture content readings should be taken with a penetrating moisture meter whenever possible because the readings are more conclusive.
Non-destructive mold growth, also called “surface mold,” can begin to occur at 17% to 19% moisture content on wood materials. This is also called “lumberyard mold.”
Always perform a meticulous inspection and take plenty of photos of the materials that got wet, especially those closest to the origin of loss.
Look for potential microbial growth where the material was:
This is typically:
In some situations, you may need to use selective invasive investigation to open a small area at the bottom of a wet wall nearest the source and inspect inside the wall.
When water damage happens, get a professional, certified restorer to the water loss as soon as possible to help stop mold from occurring.
Mold is everywhere. The goal is not to panic people or scare them with stories about how dangerous mold is. The goal is to educate them.
People should understand:
We also need to differentiate between the date of loss and the date of discovery because the clock is ticking on how long materials have been wet.
Good luck, and watch out for those fun-guys and fun-gals.
