Mold vs. Mildew: What’s the Difference?

Renters and homeowners alike are no strangers to the threatening nature of mold and mildew. These substances can fester without your knowledge and cause significant health problems for your family if left untreated. But to tackle the issue effectively, you need to be able to differentiate between mold and mildew.

While commonly thought of as the same substance, there are a few key differences. This guide goes over the differences between mold and mildew and the different treatment and prevention methods. Here’s what you need to know.

What Are the Differences Between Mold and Mildew?

It is incredibly common for folks to think of mold and mildew as the same substance. And there are some close similarities! For one, both are types of fungi. To grow and thrive, they both need water, oxygen, and food. But besides these critical points, the microorganisms are pretty different.


While people use mold and mildew interchangeably, mildew is a specific type of mold.

Mold is a broad category of microscopic fungi that generate hyphae, multicellular filaments. It can thrive on any organic matter.

Visual Appearance

One big difference is in the texture and visual appearance of the substances. Mold tends to have volume and rises off the surface on which it is growing. It is often fuzzy or slimy in texture and can grow in various colors, like black, blue, or green. Picture a rotting piece of fruit! If something is growing on the surface, it is most likely a type of mold.

On the other hand, mildew is always flat on the surface and is typically gray or black. It can appear almost powdery in texture.


Another thing that separates the two types of fungi is how they smell. While no one wants to get up close and personal with mildew or mold, this is an easy way to distinguish the two forms if you see one festering in your home.

Mildew tends to smell less strongly. It may produce a mild musky scent, akin to the smell of damp, sweaty fabric.

Mold has a much more potent odor, especially as it continues to grow. Its smell comes from the way it produces microbial volatile organic compounds. It may put off a scent like rotting wood, and it can be dangerous to breathe.

How It Grows

Mildew tends to grow and remain on top of the surface of something, like on a shower wall, windowsill, or other areas with high moisture levels.

Mold tends to burrow and fester inside of structures as well. It can grow on paper, walls, clothing, food, and anything else with moisture issues. Because of its widespread growth, removing mold is a much more lengthy process and can pose more health risks.

What Are the Causes of Mold and Mildew?

While mold and mildew are different substances, they require essentially the same type of environment to grow. The key component? Humidity.

Mold and mildew thrive in damp, humid places with little sunlight. That’s why you often see this fungus growing in bathrooms or basements. Poor ventilation, dirt, and debris can also contribute.

These substances need a food source to grow. That could be wood, fabric like cotton, or drywall. Molds cannot grow at extremely cold temperatures, so a warm, dark, humid space is ideal for them to thrive.

Under the right conditions, mold and mildew can begin to develop in only 24 to 48 hours.

How to Clean Mold and Mildew

Because mildew grows on the surface and does not deeply penetrate materials, it is far easier to clean. That said, there are still some steps of caution you should take before attempting to rid an area of mildew.

  • Make sure the room has proper ventilation. Opening windows and doors and turning on a fan can help.
  • Wear protective equipment, like a breathing mask, gloves, and eye goggles.
  • Clean mildew with a store-bought cleaner and a scrub brush. Coat the area with the cleaning product and allow it to sit; closely follow the product instructions. You can also use a DIY white
  • vinegar solution.
  • Thoroughly scrub the surface to release the mildew. Once the area is free of mildew, spray with a cleaning solution again and wipe clean.
  • Allow it to dry fully while ventilating the area.

As you can see, the process of tackling mildew removal is relatively simple and doable with basic household products.

Mold, on the other hand, is far more tricky. It poses more severe health risks than mildew, so it is best to contact a professional for support.

Mold and Mildew Prevention Tips

The best way to handle mold and mildew? Make sure it can never grow in the first place. With a few basic preventative measures, you can protect your home from these harmful fungi:

  1. Make sure rooms get proper ventilation. Installing fans is a great way to promote airflow.
  2. Moisture control is the key to prevention and mold control, and it is imperative during warm months. In particularly humid spaces, run a dehumidifier.
  3. Keep things clean! It seems obvious, but proactive cleaning goes a long way.
  4. Get your HVAC system checked regularly to ensure mechanical vents are open, clean, and free of any blockage.


When you can recognize the differences between mold and mildew, you can respond effectively and protect the health of your family and your home. And if the problem is too big to tackle alone, don’t fret! IDC Repair & Restoration has over two decades of experience helping families like yours remove mold damage and prevent it for good.

Reach out to the mold removal experts at IDC today!

Mold vs. Mildew: What’s the Difference?

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