Mold and Mildew: What's the Difference?
June 23rd, 2025
4 min read

You found some suspicious spots in your bathroom and wondered what it was. Is it mildew? Is it mold? Is there even a difference?
There is a lot of misinformation out there, and we are here to clear the air. As the experts in mold remediation in South Arkansas, Restore-It has tackled countless cases. And we are ready to share some of our knowledge with you.
Let's clear up the confusion many homeowners feel about mold and mildew! We'll explore some helpful tips for spotting and treating these pesky problems and easy prevention strategies. Say goodbye to your worries, and let's create a healthy and clean living space together.
Defining Mold and Mildew
While many people tend to separate the two terms, the reality is that mildew is actually a type of mold. However, these terms are so ingrained in the minds of people that is worth explaining what each means.
Mold
When discussing mold, people mean every type of microscopic fungi that grows as hyphae, which are multicellular filaments with a specific appearance. Mold can grow on any organic matter, including ceilings, walls, and floors, especially if there has been water damage.
Mildew
When most people talk about mildew, they refer to a very specific type of superficial mold growth, which is easier to remove than bigger, darker mold patches. The Federal Emergency Management Agency (FEMA) classifies mildew as mold in an early stage. According to the United States Environmental Protection Agency (EPA), its powdery or fluffy texture can be found on shower walls, windowsills, and other places with high moisture levels.
Differences in Appearance and Texture
One way to tell the difference between the two terms is by looking at them.
Mold
It often appears as discolored patches that can be fuzzy, slimy, or even crusty. It tends to grow deep into materials and may be difficult to remove. Depending on the size of the mold patch, you might need to call for professional mold remediation.
Mildew
Since it grows superficially, mildew is easier to spot than darker mold patches. It begins as a white or grayish powder that later turns yellow and, after some time, dark brown or black. Unlike mold, it can be easily wiped and removed.
Differences in Growth Patterns
Due to its characteristics, both mold and mildew are usually found in different places in a home. Here is where to find them:
Mold
Mold spores are found in every environment and can grow if they find moisture and the right temperature. If these conditions are found, mold can grow in any type of organic matter, including various materials like wood, drywall, and fabrics. Unlike mildew, mold penetrates deep into porous materials, breaking them down.
Mildew
Mildew thrives in damp, warm environments with poor air circulation. It commonly grows on flat surfaces like bathroom tiles, shower curtains, and damp fabrics. If you have ever found small dark patches in the grout of your bathroom tile, that's most likely mildew.
Differences in Health Risks
Both mold and mildew can pose health risks, but mold is generally considered more dangerous.
Mold
Mold can have various effects on people's health, ranging from mild allergies to severe problems. It can worsen respiratory problems for people with chronic illnesses or immune compromised. In some cases, mold can produce mycotoxins, dangerous chemicals that can cause serious health issues.
Mildew
Given that it tends to grow on flat surfaces and is considered mold in an early developmental stage, it produces milder symptoms. However, if left untreated, it can also trigger allergies and respiratory problems and worsen over time.
Differences in Potential Damage
Mold and mildew can both damage your home, but mold is generally more destructive.
Mold
Because it penetrates deep into porous materials, it can weaken structural components, causing wood rot and other damage. If left unchecked, this damage can extend through your home's foundation, requiring very expensive repairs.
Mildew
Given that it grows on flat surfaces, mildew tends to cause cosmetic damage, staining, and unpleasant odors. However, it's typically easier to clean and remove than mold. If you find it, remove it quickly before it grows larger.
Cleaning and Removal: How to Deal with Each One
Mold can grow in porous materials, whereas mildew stays on surfaces. Because of this, the approach to the cleanup is also different.
Mold
Depending on the extent of the growth, mold requires specialized cleaning solutions and techniques. For big patches (like the ones you can find after unchecked water damage) it's best to leave it to a professional mold remediation company. In some cases, affected building materials may need to be removed and replaced.
Mildew
It can be cleaned with common household solutions, such as a mix of vinegar and water. Thorough cleaning and drying are usually enough to remove it.
It's worth noting that if you attempt to do the cleanup yourself, you should wear a mask, gloves, and protective eyewear to prevent exposure to mold spores.
Keep Mold at Bay with these Prevention Strategies
Fewer things can have a big impact on your home's indoor air quality like mold. Taking preventive steps to prevent mold and mildew formation is the key to maintaining a healthy home. Here is what to do:
- Control Moisture: This is the number one step to prevent mold growth. A dehumidifier in key areas can make a world of difference.
- Improve Ventilation: Adequate ventilation, especially in damp areas like bathrooms and kitchens, is the key to preventing moisture accumulation.
- Regular Cleaning: Clean surfaces regularly to prevent mold and mildew growth. If you see mildew, remove it ASAP. If you don't find a mold spot but find a musty smell or have any of the symptoms of mold exposure, consider calling a professional.
- Address Leaks Promptly: Fix any leaks in your roof, pipes, or windows as soon as possible to prevent mold growth.
- Keep Humidity Levels in Check: You can get a hygrometer to measure indoor humidity. Keep the humidity levels between 30% and 50%.
Restore-It: Your Partner in the Fight Against Mold
So that's it! We hope this article has cleared the air if you were confused about the differences between mold and mildew. While both are types of fungi, they differ in appearance, growth, and the problems they cause. Knowing these differences is the key to effective treatment and prevention.
Contact Restore-It if you find a mold patch larger than 10 square feet. Our team has extensive experience in mold and mildew remediation and can help you identify the problem, implement the right solutions, and restore a healthy environment in your home.
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