Difference between Black Mold and Mildew – How To Identify

Black mold and mildew are both types of fungi that often appear in moist and warm areas such as a shower, or on food, or even a sheet of paper.

Even though they are commonly referred to as fungus brothers, they have some striking differences between them. Black mold is darker, almost black in color, while mildew varies in its different shades of gray and/or white.

In addition to the obvious differences in color, when observed more closely, one can spot matching characteristics between the two.

Mildew oftentimes is found in places with a large percentage of humidity present and often covered in layers of powder-like substance. On the other hand, black mold prefers warm and damp environments but is much thicker than its fecal brother mildew.

Difference between Black Mold and Mildew

Black mold and mildew are often confused but they are two very different fungi. Mildew is a type of surface growing fungus that develops in patches of gray or white on surfaces such as clothing, paper, and walls in a moist area.

Black mold, on the other hand, usually refers to Stachybotrys chartarum – a greenish black mold which results in larger infestations and often has an unpleasant odor. Black mold usually grows under carpets, behind walls, and other damp places.

It’s important to understand the differences between these two fungi so you can develop an appropriate remediation plan for your home or building.

Black Mold

Black mold, also known as Stachybotrys chartarum, is a type of fungus that thrives in moist and damp environments. 

This type of mold is known for its characteristic black color and musty odor, and it can be found in a variety of different places, including homes, offices, and commercial buildings.

One of the most common types of black mold is Stachybotrys chartarum, which is known for its ability to grow on materials such as cellulose-based products, like wood, paper, and gypsum board. 

This type of mold can also be found on other materials such as insulation, wallpaper, and ceiling tiles.

Another type of black mold is Cladosporium, which is known for its greenish-black or dark brown color. 

This type of mold is often found on materials such as fabrics, carpets, and other textiles. It can also grow on painted surfaces, like walls and ceilings.

In addition to these two types, there are several other types of black mold that can be found in different environments. 

For example, Aspergillus Niger is a type of black mold that is often found in humidifiers, air conditioning units, and other HVAC systems. It can also be found on damp wood and other materials that contain cellulose.

Black mold can also be found in basements and crawl spaces, where it thrives in the high levels of moisture and humidity. 

It can also grow on the surfaces of pipes and ducts, as well as behind walls and in ceilings, where it is often hidden from view.

In order to prevent the growth of black mold, it is important to keep your home or building dry and well-ventilated. This can be done by using dehumidifiers, running fans, and opening windows to allow for fresh air to circulate. 

It is also important to fix leaks and other sources of moisture as soon as they are detected, in order to prevent mold growth.

If you suspect that you may have black mold in your home or building, it is important to have it tested and removed by a professional. A qualified mold inspector can take samples of the mold and test them to determine the exact type of mold and the severity of the infestation. 

If mold is found, a professional mold remediator can then safely remove the mold and clean the affected areas to prevent further growth.

Difference between Black Mold and Mildew


Mildew is a type of fungus that can be found in various environments, including homes, buildings, and outdoor areas. It is known for its musty smell and unsightly appearance, and can cause a variety of symptoms if left untreated. 

Understanding the different types of mildew, where it can be found, and the symptoms it can cause can help you take the necessary steps to prevent and treat it.

Types of Mildew

There are two main types of mildew: powdery mildew and downy mildew.

Powdery mildew is a type of fungus that forms a powdery or cobweb-like appearance on the surface of plants and leaves. It is commonly found on flowers, fruits, and vegetables and can cause discoloration, distorted growth, and reduced yields.

Downy mildew, on the other hand, forms a furry or fluffy appearance on the lower surface of leaves. This type of mildew is most commonly found on plants that grow in humid or damp environments, such as indoor plants or outdoor plants that receive limited sunlight.

Where Can Mildew Be Found?

Mildew can be found in a variety of environments, including:

Homes: Mildew can form in damp or humid areas of the home, such as bathrooms, kitchens, basements, and laundry rooms.

Buildings: Mildew can also form in commercial or industrial buildings, such as warehouses, factories, and office buildings.

Outdoor areas: Mildew can grow on outdoor surfaces such as decks, patios, and sidewalks. It can also form on plants and trees, as well as on lawns and in gardens.

Is Mildew a Fungus?

Yes, mildew is a type of fungus. Fungi are a diverse group of organisms that can be found in a variety of environments, including soil, water, and air. Mildew is a type of fungus that thrives in damp or humid environments and can cause a variety of symptoms if left untreated.

Mildew Symptoms

The symptoms of mildew can vary depending on the type of mildew and the severity of the infection. Common symptoms of mildew include:

  • Musty smell: Mildew gives off a musty smell that can be difficult to ignore.
  • Discoloration: Mildew can cause discoloration of surfaces, including walls, ceilings, and floors.
  • Distorted growth: Mildew can cause distorted growth in plants, including leaf distortion and reduced yields.
  • Allergic reactions: Exposure to mildew can cause allergic reactions, including sneezing, itching, and watery eyes.
  • Asthma and other respiratory problems: Long-term exposure to mildew can cause asthma and other respiratory problems.

Which Is Worse Black Mold Or Mildew?

In terms of home damage, black mold is also considered to be more destructive than mildew. Black mold can damage the structural integrity of a building and can be very difficult to remove.

Mildew, on the other hand, is relatively easy to remove and does not typically cause structural damage.

Now, it’s important to note that black mildew is not the same as black mold. Black mildew is simply a type of mildew that is black in color. 

While it is not as toxic as black mold, it can still cause health problems and should be removed as soon as possible

Black Mold Vs Mildew In Shower

Black mold and mildew are common issues that can occur in bathrooms, specifically in showers. Both can be unsightly and potentially harmful to our health.

To get rid of black mold and mildew in the shower, it is essential to keep the bathroom dry and well-ventilated. This can be achieved by using a fan or opening a window to allow for proper air circulation. 

It is also essential to regularly clean the shower with a mild detergent or a solution of water and white vinegar. Pay attention to areas that may be harder to clean such as the grout and corners.

Another option is to use a commercial mold and mildew remover, which can be found at most home improvement stores. 

Be sure to follow the instructions on the label and use protective gear such as gloves and a mask while handling the product.

In order to prevent mold and mildew from returning, it is important to take steps to prevent moisture buildup. 

This can be achieved by using a squeegee or towel to dry the shower after use, fixing any leaks or drips, and using a moisture-absorbing product such as a dehumidifier.

Final Words

So, there you have it – the difference between black mold and mildew. With a better understanding of the two, you can feel more confident in deciding what needs to be addressed in your home. 

Just remember, if you think you’ve found something that might be hazardous, leave it to the professionals. In some cases, fixing the problem yourself may do more harm than good. Who knew all this was tucked away in what appeared to be an innocuous black stain on the wall? 

There’s no telling what kind of secrets these walls could divulge if they had working lips! As always, we at Cares Fresh  are here to help with any questions or concerns you may have; so don’t hesitate to give us a call. Let us know how we can help!

Kristen Park - Specialised Content Writer for Caresh Fresh

My name is Kristen Park and I am a senior writer specialising in how-to guides and home cleaning information at Cares Fresh. As a researcher, I take pride in digging deep to find every small detail on a topic and explaining it in a way that is easy for the reader to understand.