Comparing Mold and Mildew

Feb 1, 2023 | Mold Remediation

Understanding the Differences Between Mold and Mildew


Many people use the words “mildew” and “mold” interchangeably. However, they are not exactly the same.

“Mildew” is a common name used to describe certain types of surface-level mold, which make them relatively easy to remove.

“Mold” is used in a broader sense to refer to all types of indoor molds (Aspergillus, Cladosporium, Stachybotrys chartarum, etc.), which are more invasive since they can penetrate the surface of materials, making them more difficult to remove.

This guide will explain the distinctions between mold and mildew, and illustrate the effects they can produce.



Photo: Mildew indoors. Dept of Plant Pathology Archive, NCSU,



Mildew typically has a flat and powdery or fluffy appearance, usually white, gray, or yellowish in color, and may turn brown or black over time.

It has a distinctive musty smell and often appears as small spots, but if left untreated, it can spread and cover larger areas.

Places where it appears

It is commonly found in damp and humid areas such as bathrooms, kitchens, basements, and attics, as well as in organic materials like fabric, paper, leather, and wood.

Capacity to damage

Since mildew typically grows on surfaces and can be removed relatively easily, it is less likely to cause structural damage to a house than mold. However, prolonged exposure to mildew can weaken materials and surfaces where it grows, such as drywall, paint, or fabrics.

If the mildew is not addressed quickly and properly, it can cause discoloration and spread to other areas of the home, making it harder to remove.

It is important to address mildew as soon as it is noticed and take steps to remove it and prevent its return.

Health problems

Mildew is generally considered to be less harmful than mold. However, it may cause health problems for some people as well, especially those with allergies, asthma, or other respiratory issues.

Exposure to it can cause symptoms such as headaches, sneezing, coughing, throat irritation, runny nose, red eyes, and difficulty breathing.



Mold grows in the form of patches that penetrate beneath the surface of materials. It has a distinct musty smell and appears as irregular and fuzzy spots and is commonly black or green in color, but can also be blue, yellow, brown, gray, or white.

Places where it appears

It grows inside objects and structures with moisture problems and in damp areas such as bathrooms, kitchens, basements, and attics.

Capacity to damage

Mold can cause damage to a variety of materials and surfaces, and if not addressed, it can lead to structural damage over time.

Some common materials that mold can damage include:

  • Wood: Mold can cause wood to rot and weaken.
  • Drywall: Mold can cause drywall to weaken and collapse.
  • Insulation: Mold can cause insulation to lose its effectiveness and need to be replaced.
  • Carpets and fabrics: Mold can cause fabrics to discolor, rot and weaken.

Health problems

Exposure to mold can cause a wide range of health issues, including allergic reactions (sneezing, congestion, irritation of the eyes, throat, and skin) and respiratory problems (shortness of breath, asthma attacks).

The specific symptoms and severity of the effects can vary depending on the individual. Not all people exposed to mold will experience all of these symptoms and not all will experience them to the same degree.

Children and individuals with weakened immune systems are particularly susceptible to the effects of mold and may be more seriously affected. However, exposure to mold can cause health problems for anyone.

How to prevent mold and mildew

Here are some steps you can take to prevent mold and mildew:

  • Control moisture: The most important step in preventing mold and mildew is to control the amount of moisture in your home. Therefore, use exhaust fans in bathrooms and kitchens, and fix any leaks and drips as soon as they occur.
  • Clean and dry surfaces: Make sure to dry the surfaces thoroughly. For instance, wipe down shower walls and floors after every use.
  • Use mold inhibitors: Use mold inhibitors on paint and other surfaces in high-moisture areas like bathrooms and kitchens.
  • Regularly inspect your home: Try to quickly detect signs of mold and mildew, particularly in high-moisture areas like bathrooms, kitchens, basements, and attics.
  • Keep an eye on temperature: Avoid condensation on windows and walls.
  • Use a dehumidifier: A dehumidifier helps remove excess moisture from the air.


It’s very important to address mold and mildew as soon as they are noticed and take steps to remove them and prevent their return.

If you are dealing with these problems, The Phoenix Restoration’s mold damage service can help you.

Contact us and we’ll be glad to assist you!