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Finding mold stains on the wall or ceiling of your home is certainly troubling. Mold is not something to mess around with. According to The U.S. Centers for Disease Control and Prevention, it can cause a range of health concerns, including a sore throat, burning eyes, wheezing, allergies, or even lung infections.
Before you start thinking about how to test for mold or start remediating it, it can help to understand whether you’re dealing with a new issue or if the mold has been there for a while already. Tony Abate, a certified mold inspector and the vice president and technology officer at AtmosAir Solutions, explains that the age of the mold provides useful information about the extent of the problem you’re facing. “A spot that has just appeared may have less growth [on the underside of the surface] than a spot that has been there where the growth on the underside is likely more significant and the problem larger.” Ahead, discover how new and old mold can differ based on their color, texture, odor, and other characteristics.
Color
While the type of mold you’re dealing with can also impact its color, new and old spores also look different. According to Abate, “A brighter appearance would indicate newer growth, while older growth would be more muted or duller in appearance.” Older mold typically takes on a gray, blue, or black color.
Identifying the difference between mold and mildew can be a bit more challenging if you’re dealing with new mold. That is because, like new mold, mildew is often white or light gray in color. However, as the mold establishes itself and changes to a black, blue, or darker gray color, it should be easier to distinguish it from mildew.
Texture
The texture of the mold you’ve identified can offer information about its age, too. Newer mold will look slimy. You may also be able to see some webbing as the fresh mold is starting to establish itself and spread over a surface. If you were to try to wipe it off the surface, it likely wouldn’t come off very easily.
On the other hand, inactive mold lacks the slimy appearance of mold. Instead, it has a powdery texture. When wiped with your hand or a cloth, some of the mold may fall from the surface it is covering.
Odor
You may already know that odor is one key characteristic that can help you determine whether you’re dealing with water damage or mold, but did you know that it can also be a clue to the age of the mold you’ve spotted? Fresh mold typically has a stronger odor—that musty smell that we associate with mold and mildew. On the other hand, according to Abate, “Older growth can be less odorous, especially if the mold has become inactive.”
Moisture
“Moist environments provide one of the building blocks for mold growth. Any environment that has relative humidity or may have had water intrusion that was not cleaned up properly can foster mold growth,” says Abate. You may be able to determine the age of the mold based on when water or moisture were a problem.
For example, if your toilet recently overflowed in the bathroom, and you just discovered stains on the wall, they may have been caused by this recent leak and are likely fresh. Conversely, if water infiltrated your basement a few years ago (and you thought you had fully resolved the problem), but recently found mold on one of the affected walls, it might have been there for a few years already.
Growth
If you’ve been checking on those mold spots on the walls regularly, its rate of growth can also provide some clues into whether it is fresh. New mold often grows quickly. So, if you’ve noticed it spreading more rapidly, it might be a new problem.
However, Abate cautions against relying solely on the visible growth of the spores. He explains that the mold may still be growing where you can’t see it, such as behind your walls. “If you suspect mold growth or smell mildew odor, contact a professional to evaluate the situation and oftentimes a fast remediation can prevent a more extensive and costly problem. This is especially true if you experience any type of water leak,” he says.
