Mildew and mold are unwanted guests in any space. They stain surfaces, pollute the air, and even cause health issues. The difference between mold and mildew is often a topic of contention. Mildew is a form of mold, and both depend on warm, damp places with cellulose (plant matter) for their survival. But that’s about where their similarities end.
What’s the difference between mold and mildew, and how do you know whether you have mold or mildew growing in your house? Let’s look at ways to identify the two, how to remove them, and how you can prevent them from making your home their home.
What is Mildew?
Mildew is a form of fungus that can grow on just about anything, including paper, leather, walls, ceilings, wood, and fabrics such as clothing and draperies. It’s gray or white and often powdery and flat in appearance. You’re more likely to spot mildew in bathrooms, kitchens, and basements where it’s humid and warm. Mildew also likes the dark, so it can often be found under your sinks and in other poorly-lit spaces like closets, cabinets, and pantries.
What does mildew look like? It grows in patches, so watch out for flat, dot-like blotches of gray or white. Mildew can easily spread on surfaces, so if you spot a patch of it, it’s a good idea to treat it right away (more on that later in this article).
What is Mold?
A mold, or mould if you prefer the Queen’s English, is a fungus that grows in the form of multicellular filaments called hyphae. Mold is especially fond of food and damp, moisture-prone surfaces like floors, carpets, ceilings, appliances, furniture, and uninsulated walls.
Mold, like all fungi, is not a plant and does not photosynthesize to produce energy. Instead, it’s heterotrophic, which means it absorbs nourishment from its environment. Mold needs moisture and oxygen to survive; it can’t grow on clean, dry surfaces. And since ultraviolet (UV) light from the sun kills most mold and spores, mold mostly lurks in dark spaces that sunlight can’t reach.
Think of the dirt, grease, and oils that collect on your shower tiles—with regular use, showers are a constantly moist environment. In fact, a shower that’s used over and over without time to dry out can quickly turn into a haven for mold growth.
Mildew vs. Mold
What is the difference between mold and mildew? Their defining characteristics can be used to separate them in the following ways:
Mildew is most easily identified through its powdery appearance. It grows in flat patches of white, gray, or pale yellow on moist surfaces, though it will turn black or brown after a while. It often resembles small spots, or dots, that spread outward as it grows and spreads.
On the other hand, mold is typically fuzzy or slimy. Though some molds may bear a resemblance to mildew, mold is typically darker, with shades such as deep green and black. Mold can eat its way into its base (the host surface on which it’s growing), causing it to rot and degrade. This is especially common on wood and painted walls, and can lead to considerable structural damage if unattended for prolonged periods of time.
- Health Risks
Most people believe mildew is harmful only to plants, but it can also pose health risks to humans. Allergic reactions to mildew spores typically manifest as coughing, headaches, a sore throat, and other cold-like symptoms including a runny nose, sneezing, and itchy eyes—and can be especially dangerous if you suffer from asthma.
Mold is often considered the more threatening of the two, and rightly so. Prolonged exposure to mold can cause a variety of health problems, including various allergic reactions, respiratory problems, cold-like symptoms, migraines, depression, and extreme fatigue. In the case of black mold vs. mildew, black mold is much more toxic, and you should have a professional remove it immediately.
Mold vs. mildew--which is harder to get rid of? All it takes to remove mildew is a good mildew cleaner and scrub brush. Clean the affected area thoroughly and allow it to dry completely.
Since mold can be an early warning sign of a moisture problem inside walls or ceilings, it’s a good idea to deal with it as soon as you spot it. You can easily remove most mold using an antimicrobial spray treatment. If your walls and/or ceiling have mold, it’s a good idea to repaint the affected areas after treatment, using an anti-mold primer and anti-mold paint additive. However, if you are not sure what mold you are dealing with, you are better off leaving it to a professional.
That being said, it is possible to prevent mildew or mold from developing in the first place.
Tips to Prevent Mold and Mildew Growth
1. Keep Surfaces Clean
Closets, dresser drawers, basements—these are all places where mildew and mold like to grow. Keep these as clean and dry as possible to deny the fungi a conducive environment for growth.
Dirt and greasy build-up, combined with a damp, humid environment, make a delicious food source for both mildew and mold, whether it be on kitchen walls, clothing, or any of the surfaces mentioned earlier. That’s why keeping your home clean is so important in stopping mold and mildew growth.
Tip: For centuries, applying a thin coat of paste wax to wood furniture was, and still is, a common moisture and dirt repellant. It also gives your furniture a rich shine that brings out its natural beauty.
2. Get Rid of Dampness
Moisture creates a perfect environment for mold and mildew to thrive. If spores are introduced into the air, they may settle onto surfaces and start spreading. A damp, dimly lit basement, bathroom, or any other clammy unventilated room is often caused by moisture condensation from humid air onto cooler surfaces. Heating your house for a short time, and then opening the windows to let out the moisture-rich air, can help remove dampness and dry things out.
In a small closet, you can run an electric light continuously every few days, which provides enough heat to help prevent mildew. If you find damp or soft spots in walls or fixtures, that could indicate significant rot and a history of water penetration. Be sure to contact a professional immediately to prevent structural damage.
3. Dry the Air
Cool air is less humid than warmer air. That’s why running a dehumidifier and your home’s air conditioning is a great way to remove moisture from the air and help prevent mildew and mold.
Tip: Get a dehumidifier rated for twice the size of the room you want to put it in, to make sure it’s removing as much humidity as possible.
If you live in a home without air conditioning, open your windows regularly to increase circulation and cool the air.
4. Use Chemicals That Absorb Moisture
Silica gel, activated alumina, anhydrous calcium sulfate, and molecular sieves may be used to absorb moisture from the air and clothing. They’re not harmful to fabrics and are easy to use. Simply place sachets or bags in strategic places of your closets.
You can also place an open container of silica gel in the closet—on a shelf, preferably, or on the floor. An alternative is placing rock salt or ice melt in shallow, disposable containers in the areas of concern; take care not to get ice melt on any carpets or fabrics, as it can damage the fibers.
5. Circulate the Air
Air movement is essential for removing moisture from any room. Ventilation allows dry air to enter a room while removing excess moisture. When natural breezes are not sufficient, you can use electric fans placed in a window, set in a wall, or vented to the attic to move air from your house.
In poorly ventilated closets, make sure to hang clothes loosely so air can circulate around them, and let wet clothing (coats wet from rain, for example) dry before hanging them in your closet. Here are some other tips for preventing mold and mildew.
The key to treating both mildew and mold is to wipe them out of your home immediately. Managing these nuisances accordingly will safeguard your home from permanent damage.
The contents of this article are provided for general guidance only. First American Home Warranty does not assume any responsibility for losses or damages as a result of using this information.