Mildew vs. mold: How to tell the difference

Mildew vs. mold: How to tell the difference

The differences between two uninvited guests and how to banish them

Mildew vs. mold: Key tips to remember

  • Mildew and mold are both fungi
  • Both thrive in moist environments
  • Both can cause home damage
  • Both can cause health problems
  • Take steps to remove and prevent them

Let’s face it. Nobody ever invited mildew or mold to a party or was stoked when either one showed up. Aside from being uninvited guests, mildew and mold can damage your home and cause serious health problems. These ickiest of interlopers are closely related, and sometimes one can lead to the other. Still, if you have a pretty good handle on what they are and where they come from, you’ll understand how to tell the difference between mold and mildew and be better at keeping them from making an appearance and causing a major buzzkill. If you’re wondering whether your home warranty covers mold, we have a post for that. Meanwhile, read along as we tackle the ins and outs of how to tell mold from mildew and beyond.

Mildew vs. mold and the differences between them

 As microorganisms of the fungi persuasion, mildew and mold share some characteristics. They thrive in similar environments and sometimes look relatively identical. Both can grow in, around and on just about any surface. Knowing how to tell the difference between black mold and mildew is a great first step toward banishing them from your home and keeping them out for good. While they share similarities, they also have distinct differences. Here’s more on both: 

  • Mildew: Thriving in humidity, mildew can even appear on plants. Mildew’s distinctive, musty smell is recognizable as that of sour socks or wet laundry left too long in the washing machine after a load has run its course. If caught before it proliferates, mildew doesn’t usually leave lasting damage, though it can lead to more powerful strains of mold if left to grow.
  • Mold: A more dangerous invader than mildew with the potential to destroy structures and impair organ- and immune-system function, mold is much more likely than mildew to cause lasting damage to parts of a home or the long-term health of its inhabitants. Mold can grow in the dark and eat into its base, making it yet more difficult to eradicate. Compared to mildew, it stinks like rot because it’s more volatile. Under the right moist conditions and with continuous food supplies, it can expand exponentially 

Which is which — discerning visually

What do mildew and mold look like? Learning to tell the difference between mold and mildew is as easy as knowing what to look for.

  • Visual clues (mildew): Identifiable via its lighter shades of white and gray that gradually turn into flat, powdery little brown dots, mildew is a surface fungus and an early stage of mold. Mildew dots are easy to spot because they tend to spread outward instead of upward, remaining flat and looking like a sprinkling of powder on a flat surface, one you might be tempted to simply brush away.
  • Visual clues (mold): Mold can be white, fuzzy, green or sticky. It’s also identifiable via its darker shades of yellow, red and black. Mold on a wall, floor, ceiling or furniture grows upward instead of remaining flat. It can grow underground, sometimes looks like dirt, and can be fuzzy or even slimy, indicating a more serious infestation of nefarious microorganisms.  

Why do mold and mildew form

Mold and mildew grow when they have food sources. The food source could be as simple as the walls of your home. Wet drywall is a delicacy enjoyed by mildew and mold spores across the world, and their spores can start to grow in less than 24 hours if a water source is added to a food source and oxygen is available. For example, if your A/C vents cold air into a closed closet as you try to keep temperatures down in the heat of summer months, you may be creating a perfectly moist environment for some disgusting, uninvited guests.

What underlying issues can cause mold and mildew

Mildew and its gnarlier cousin mold love to grow in enclosed areas where moisture is allowed to thrive, which is why you find both so often in areas exposed to water damage, a sitwwwion these nasty little bugs live to exacerbate. Although some varieties of both tend to favor warmer temperatures, that is not a requirement for either to proliferate. For both to grow, all they need is a spore, which can grow with food, water and oxygen.  

Health concerns with mold and mildew

Anyone living in your home prone to allergic reactions is likely to react to even a minimal invasion of mildew or mold. Typical symptoms can initially seem like normal allergies but quickly worsen and should never be ignored. From respiratory ailments to cold symptoms to headaches, fever and breathing problems, mildew and mold can grow fast and cause serious health trouble, even for healthy adults who aren’t used to experiencing allergies. 

Among the worst strains of both microorganisms is black mold (stachybotrys chartarum), which can cause more severe health problems, like memory loss, mood swings, nervous-system damage, phantom pains, auto-immune disorders and even depression. If you’re experiencing any of these symptoms and suspect your home has been infected with black mold or something like it, it’s best to have a professional evalwwwe your living space as soon as possible.

How to treat (and eliminate) mold and mildew

If you’d like to know how to get rid of the smell of mildew, as a general rule, it’s best to go after mildew (or mold) immediately, preventing it from spreading and impacting your home and family more than it already has. However, before treating mold or mildew, ensure you have eye protection, gloves and a mask. Other than this basic safety equipment, a bucket with hot water and a mild detergent might be all you need, although a 50-50 vinegar-and-water solution could work just as well, as would a weak solution of bleach and water. Make sure you use a new sponge so you don’t spread spores. 

Get rid of the soggy, rotten, mildewed or molded materials, spray the remaining area with clean water to prevent spore movement, spray with your cleaning solution, and start scrubbing. Then let everything dry for at least two days and nights before disturbing the area or painting anything. Mildew is easy to scrub away with any of these solutions, but if you’re dealing with mold, you’re in a new ballgame. You can clear some molds away with the same solutions and methods, but black mold calls for a professional because you won’t want to accidentally spread it to other areas of your home. For more helpful info and ideas, read our FAQ about bathroom mold removal.

How to prevent mold and mildew

Preventing mildew and mold centers around keeping your home dry and clean with adeqwwwe ventilation, good airflow and unblocked vents. Aside from those general rules, it helps to use fans and dehumidifiers, and open your windows to get natural airflow throughout the home whenever possible. Here’s why dehumidifiers are important. When it comes to mildew and mold, moisture is your enemy, so do your best to make sure it’s not trapped anywhere, like that stuffy, closed, unventilated shower, clogged dryer vent or weak stove hood.

The information in this article is intended to provide guidance on the proper maintenance and care of systems and appliances in the home. Not all of the topics mentioned are covered by our home warranty or maintenance plans. Please review your home warranty contract carefully to understand your coverage.

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