Mold vs. Mildew: What’s the Difference in the Home?

Last Updated On December 20th, 2023
Mold vs. Mildew: What’s the Difference in the Home?

Key Takeaways

  • Mold vs. Mildew Distinctions: Mold and mildew are both types of fungi that thrive in damp environments, but they have distinct characteristics. While mildew is a type of mold, not all molds are mildew. Recognizing their differences is essential, but addressing any fungal growth promptly is crucial for your health and home.
  • Fungal Growth and Impact: Both mold and mildew grow in warm and damp conditions, but they differ in appearance, preferred growth locations, and effects. Mold, which grows from airborne spores, can cause structural damage and health issues, including respiratory problems. Mildew, often found on flat surfaces like shower walls, is less destructive but can still trigger health issues.
  • Preventing and Managing Mold: Preventing mold growth is crucial. Adequate ventilation, maintaining humidity levels, and using mold-resistant materials in your home can help. Mold-resistant mattresses can significantly reduce the risk. Timely action is essential when dealing with mold and mildew, and if a mattress is contaminated, replacement is often the best solution to ensure your health and safety.

Mold and mildew are both home hazards, but though the two are often talked about together, they are not the same. Technically speaking, mildew is a type of mold, which means the two of them do share some commonalities. But while mildew is a mold, a mold is not necessarily a mildew.

Mold and mildew are fungi that thrive in warm, damp conditions and can grow on various surfaces. Outside of that shared description, the two do have a few significant differences. You can determine which is which by their appearance, preferred places to grow, and the effects they have on their surroundings.

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What is Mold?

Mold grows from tiny spores that float in the air. As the spores reproduce, they form mold clusters that can be seen by the naked eye.

This fungus plays an important role in nature, breaking down dead organic matter, such as fallen trees. The nutrients contained in these organic materials are then released for other living things to use.

The CDC says Verified Source Centers for Disease Control and Prevention (CDC) The United States’ health protection agency that defends against dangers to health and safety. View source mold is commonplace in homes and other buildings and is not so helpful once it finds its way inside. Aside from the health effects of living with mold, mold can also cause structural damage to your home.

What is Mildew?

Mildew is a type of mold that grows on flat, damp surfaces. You’ll often find it on window sills or the walls of your shower.

Mildew tends to cause less permanent damage than mold. As a surface fungus, it’s often easy enough to eliminate with a simple cleaning solution. Still, it’s important to tackle mildew when you see it in the home.

Where Does Mold Come From?

Mold has been around for millions of years, and mold spores can get inside your home through an open door, window, or vent or be carried inside on an item of clothing or a pet.

Mold will then grow in moist places inside your home, such as near a roof leak or pipe.  Surfaces that can support mold include paper products, ceiling tiles, wood, paint, dust, wallpaper, carpeting, fabric, insulation, and drywall.

Differences between Mold and Mildew

Though we list how mold and mildew differ by appearance, where they like to grow, and the effects they can have on surfaces and your body, we should note that it’s essential to take all fungal growths seriously. Knowing what type of fungus is growing in your home is not as important as taking immediate steps to remove it.


Mold tends to be described as “fuzzy” or “slimy,” with a green or black color. Mildew might be described as “fluffy,” “powdery,” or “downy,” with a white, yellow, or gray color.

Powdery mildew is more likely to have a white or gray color that can turn yellow, black, or brown as it spreads. Downy mildew often starts yellow and grows brown.

Preferred Environments

Where you find a fungal growth can help you determine whether it’s mold or mildew. For example, if something is growing on food that’s been left to sit, it’s probably mold. Mildew can thrive on food, but you’re more likely to find it in flat, moist areas.


Molds and mildews can affect the surfaces they grow on differently. Your body may also react differently, depending on the type of fungi.

When mildew grows on flat surfaces such as a tile floor or bathroom wall, the effect is mostly cosmetic. That said, mildew spores can cause coughing and headaches if inhaled.

Mold can do far more damage to your home and your health. Aside from breathing difficulties, mold exposure can be linked to heart problems, joint pain, fatigue, and depression.

Mattresses and Mold

Quick Guide: A 30-Second Summary

Best Mold-Resistant Mattress Amerisleep Organica
Best Mildew-Resistant Sheets Amerisleep Bamboo Sheets

Most of us would find it gross to sleep on a mattress overrun with mold, but few of us may understand the steps we can take to prevent that from happening.

Moisture and poor ventilation can promote mold growth in your mattress, just as these two factors can enable mold to thrive anywhere else. That means you need to think about how much you might sweat at night and how well air can circulate through your mattress to remove heat and moisture.

Mold can also flourish in a mattress after it’s been submerged in water. This is why it’s important to dry a mattress after water damage if you can and replace it if you can’t.

Preventing Mattress Mold

The best way to make sure your mattress stays cool and dry during the night is with the right bed foundation. A good foundation often is slatted instead of solid. This design allows air to circulate through the bottom and remove collected moisture. It’s best to make sure the slats are no more than 2.75 inches apart to provide consistent support and limit sagging.

The risk of mold growth is also why we strongly advise against keeping a mattress on the floor. A slatted foundation can prevent moisture buildup by letting air move through the bottom of the mattress, while a solid floor hampers air circulation and can make your mattress a damp environment that allows mold to flourish.

The likelihood of a moldy mattress on the floor increases if the floor is damp or prone to moisture buildup. This kind of wet flooring can happen in basements or areas with high humidity levels. This is why a dehumidifier can be a crucial part of making a basement into a bedroom.

When a mattress is in contact with a damp floor, moisture can seep into the bottom of the mattress and create a wet environment that is ideal for mold growth.

The right bedding can also help your mattress remain dry while you sleep. If you find yourself waking up in a sweat, exchange your current bedding for something lighter. While a little bit of sweat is unavoidable, cutting down on how much you sweat limits how much moisture your mattress absorbs.

Encasing your mattress in a waterproof protector is one of the best ways to prevent stains and mold growth. The protector’s tight weave keeps out sweat and other fluids that can create the moist environment needed for mold to thrive.

The possibility of mold and mildew growing in damp conditions is why we recommend keeping your mattress as dry as possible when cleaning it. A thorough vacuuming, followed by a sprinkling of baking soda is an excellent way to freshen and deodorize your mattress without using water. Once the baking soda has been left to sit for a few hours, vacuum up the remainder and cover it with a protector and sheets.

Sometimes it may be necessary to use liquids to clean your mattress, such as vinegar or hydrogen peroxide. If you do so, we usually recommend spot-cleaning stains by wetting a cloth with your cleaning solution and blotting the stain, instead of spraying liquids directly onto your mattress. Make sure your mattress is in a ventilated area and fully dry before you redress it with your bedding.

Is a Moldy Mattress Salvageable?

Can you remove mold and mildew once it’s found a home in your mattress? While it may be possible to eliminate surface-level mold and mildew, there’s no way to kill mold and mildew once they’ve made a home inside your mattress.

The dangers of mold and mildew are high enough for you to be better off buying a new mattress once you see signs of mold. Otherwise, you risk damaging your health by sleeping on a mattress that you may not have gotten clean enough. It’s much better to replace the mattress as soon as you can.

How do you dispose of a mattress that’s overrun with mold? You may have to call around and inquire with recycling centers or junk removal services and ask if they’ll accept it. Obviously, a moldy mattress is too much of a health hazard to donate and we wouldn’t recommend exposing yourself to mold spores by trying to upcycle it.

How Do I Know If I Have a Moldy Mattress?

Sometimes, mold on a mattress is easy to spot. The surface of the mattress may be discolored. The mold may appear as green, black, or white spots  And if the mold growth is extensive, you may see visible signs of decay, such as crumbling or soft spots on the surface.

Even if you can’t see these signs because the mold has taken root deep inside the mattress, you may notice a musty odor coming from the mattress. Mold inside a mattress can incite respiratory issues such as coughing, wheezing, and cause difficulty breathing. These symptoms are due to the mold spores that are released into the air and then inhaled. You may also experience allergic reactions such as sneezing, itching, and watery eyes.

Preventing Mold and Mildew in the Home

It’s best to limit the chances of mold growing, rather than have to take steps to control mold once it’s taken root in your home. Recommended mold prevention measures include:

  • Keeping your home well-ventilated, especially high moisture areas like the shower and bathroom, laundry room, and kitchen. Make sure you have exhaust fans for these spaces that vent outside of your home. Open windows when weather permits can also increase air circulation. In warmer weather, this is also a good way to cool down a room without expense.
  • Making sure air ducts and vents are regularly cleaned. Mold and mildew can grow in air ducts, so it’s important to have them cleaned routinely by a professional.
  • Maintaining a 30 to 50 percent humidity level within your home. A dehumidifier or an air conditioner will help, particularly during the more humid months.
  • Similarly, using an air purifier will keep free-floating mold spores from settling in your home.
  • Looking for mold on a mattress when you clean it monthly. An airy foundation and a mattress protector can significantly decrease the chances of mattress mold developing.
  • Quickly fixing any leaks in your home’s structure or plumbing.
  • Removing carpeting from damp areas such as your bathroom or basement. Similarly, keep an eye on bathroom rugs.
  • Keep an eye on plants in the bedroom and around the home. While indoor plants are beautiful, but they can also contribute to mold growth. Be sure to monitor the soil moisture level in your indoor plants and avoid overwatering them.

Be especially careful if your home is flooded, whether it’s a natural flood or a human-made cause such as a burst pipe. The Federal Emergency Management Agency (FEMA) states that mold and mildew will develop within 24 to 48 hours of water damage and exposure.

Mold Resistant Mattresses and Other Products

While you can take steps to remove moisture from your home that promotes mold growth, it’s also smart to look into home goods that resist mold growth. For example, using mold-resistant paint and caulking in bathrooms, kitchens, and other high-humidity areas can keep spores from settling and growing. Choose such mold-resistant materials for carpets, upholstery, and curtains.

When it comes to a mold-resistant mattress, it’s difficult to beat the power of natural latex foam. Latex is a material derived from the sap of rubber trees and is naturally resistant to mold, mildew, and dust mites. This is because latex has an open cell structure that allows for proper air circulation, which helps to prevent the growth of mold and bacteria.

Additionally, latex mattresses are typically made without the use of synthetic materials, such as polyurethane foam, which can be more prone to mold growth. Instead, natural latex is often used in combination with organic materials, such as cotton or wool, which can also help to prevent mold growth.

These materials have other benefits, as well. Cotton, wool, and latex are all naturally cooling, and wool is typically used to establish a mattress without fiberglass. Like mold spores, fiberglass particles can cause irritation if inhaled, so it’s best to avoid them entirely.

It’s important to note that while the benefits of latex mattresses include natural mold resistance, proper care and maintenance are still necessary to ensure their longevity and prevent mold growth. This includes regularly cleaning the mattress surface and minimizing exposure to moisture and humidity with a waterproof mattress protector.

You also don’t have to give up on a memory foam or hybrid mattress if those are what you find most comfortable. Many manufacturers add specialty materials and advanced ventilation to increase their mattresses’ mold resistance.

Removing Mold and Mildew

What do you do if your prevention steps aren’t enough, and you find mold and mildew growing in your home? It’s possible to take care of the problem on your own.

First, make sure you take steps to protect yourself. Verified Source Centers for Disease Control and Prevention (CDC) The United States’ health protection agency that defends against dangers to health and safety. View source Wear equipment such as goggles, gloves, and masks to protect your face and skin. Keep air circulating while you work. Open all the doors and windows that you can, and use fans and dehumidifiers.

Remove all moldy items. Once mold starts growing in carpeting, on tiles, and in drywall and wallboard, the only realistic recourse is to toss and replace it. It’s important that you remove all mold before you cover up an infected area with paint or caulk.

You can kill mold on hard surfaces with commercial cleaners, white vinegar, or a bleach solution that’s no more than a cup of bleach to a gallon of water. If you use bleach, make sure you have access to fresh air, wear protective gear, and don’t mix the bleach with any other household cleaners.

Mold infections that take up less than 10 square feet (such as a shower) can often be treated by yourself, but if you have a large-scale mold infestation, you may need to call a professional mold removal service.

Is it possible you’ll have to leave your home behind if it’s overrun with mold? The CDC recommends Verified Source Centers for Disease Control and Prevention (CDC) The United States’ health protection agency that defends against dangers to health and safety. View source you speak with your doctor about that possibility if you show signs of illness triggered by exposure to mold. It’s a decision best made on a case by case basis, according to the CDC.

Mold vs Mildew

Frequently Asked Questions

Can mold or mildew make you sick?

Yes, mold can make you sick Verified Source National Library of Medicine (NIH) World’s largest medical library, making biomedical data and information more accessible. View source especially if you have a respiratory condition such as asthma. Many people also experience allergic reactions to mold, such as sneezing. Even if you do not have a mold allergy or asthma, mold can irritate your eyes and cause a sore throat, skin rash, headache, and congestion.

Other at-risk groups when it comes to mold include:

  • Babies and children
  • Older adults
  • People with compromised immune systems
  • Those with chronic lung disease

Are mildew and mold the same thing?

Yes and no. While mildew is a type of mold, mold is not always mildew. FEMA specifically calls mildew a “mold in (an) early stage.”

One of the main differences between the two is their appearance. Whereas mold is often considered slimy or fuzzy, mildew tends to look more powdery and fluffy.

Which is worse, mold or mildew?

Both mold and mildew can have terrible impacts on your health. Mold is often thought of as the worst of the two since mildew is less likely to cause structural damage, but either fungus can cause respiratory problems and other health issues.

As the Centers for Disease Control states, Verified Source Centers for Disease Control and Prevention (CDC) The United States’ health protection agency that defends against dangers to health and safety. View source “It is not necessary to determine what type of mold you may have growing in your home or other building. All molds should be treated the same with respect to potential health risks and removal.”

How do you kill mildew?

There are a variety of ways to get rid of mildew once it starts growing. You can try soaking the affected area with white vinegar and letting it sit for a few hours. You can also try applying hydrogen peroxide to the mildew, and wipe it away after leaving it alone for about 10 minutes.

If you use bleach to clean up mold, never mix it with ammonia or other household cleaners. Use a cup of bleach to a gallon of warm water to create an effective cleaning solution.

Does a musty smell mean mold?

A musty smell can mean that mold or mildew is present in your home. There doesn’t need to be a lot of mold for there to be a musty odor, nor will mold necessarily have a musty smell if it takes up residence in your home. Before you try to get rid of or cover up the scent, make sure to check for any mold or mildew growth.


While it can be nice to know whether you’re dealing with mold or mildew in your home, it’s far more critical that you remove all fungi in your home once you spot it. There’s no such thing as a “good” mold when it comes to your home’s structural stability and your own health, especially mold in the bedroom that affects you when you are asleep and vulnerable.

It’s also worth keeping in mind the saying ‘An ounce of prevention is worth a pound of cure’ when it comes to mold in the home. It’s usually simpler to keep mold from settling than remove it once it’s growing, and it can be as easy as relying on a few devices. For example, one of the many benefits of an air purifier is that it will trap mold spores and other airborne allergens.

Looking into dehumidifiers and mold-resistant mattresses and routinely checking your home’s condition to ensure it’s still mold-free can save you a lot of later hassle.

About the author

Mitchell Tollsen is a graduate student and a freelance writer who’s contributed to the Early Bird blog for three years. Mitchell’s always been fascinated by the science of sleep and the restorative processes our bodies undergo when at rest. The self-titled “Sleep Expert” is always looking for ways to improve his shut-eye, and throughout the years has implemented numerous lifestyle changes and tried dozens of sleep-promoting gadgets to determine the best ways to truly get better rest.

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