How to Identify Mold vs. Mildew

When discussing mold vs. mildew, the terminology can seem confusing; they are often lumped together. However, they are not interchangeable; mildew refers to a specific type of flat-growth fungus and can include some types of mold. Both fungi develop due to excessive, unchecked moisture in confined spaces, with some strains thriving at higher temperatures. These fungi can eventually damage the home or cause health concerns.

Read on to learn about the differences between mold and mildew so you can safely eradicate these growths to keep your home and family safe.

What Is Mold?

Mold spores are microscopic and are present in all indoor and outdoor air. They only become visible to the naked eye once a large colony has formed. Mold can be identified by looking like green, blue, red, or black specks of dirt. They are often fuzzy. At-home tests can help you determine the presence of mold.

What Is Mildew?

Mildew is a fungus that looks like flat, white, or gray powdery dots in its early stages before turning brown. It is an early stage of a mold growth colony and often needs moist conditions. Mildew is most commonly found in bathrooms and kitchens.

Differences Between Mold and Mildew

While mold and mildew are fungi that need water, oxygen, and food to live and survive, they differ in several ways.

• Appearance: Mold usually appears as darker colors, such as green, blue, red, or black specks, with a fuzzy raised texture; mildew usually starts as flat, white, or gray powdery dots that eventually turn brown.
• Smell: Mold has a strong, pungent odor like rotting meat; mildew smells sour and musty, like wet towels left too long in a pile.
  
• Growth: Mold grows to look like fuzzy, raised-textured specks, while mildew grows to look like flat, powdery dots.

Mold and Mildew Health Concerns

The presence of mold and mildew in the home may affect the health of both humans and pets. While some people may not be affected, others who are especially sensitive may experience symptoms such as itchy eyes, wheezing, or a runny nose. People with asthma or allergies will feel the most severe reactions to mold and mildew.

How Mold and Mildew Form

Mold and mildew need the right conditions for growth. To begin, mold spores act as a type of seed. Spores grow with three factors: food (such as soil), water, and oxygen. Increasing or decreasing any of these factors will cause mold and mildew to grow or die.

Spores land on the surface, germinate, and grow. Mold and mildew may start 24 to 48 hours after dampening the surface. Mildew's white-gray spots spread outward, not upward, remaining on the surface. Mold, though, eats into its base—which makes it harder to remove—and sometimes grows upward.

Issues That Cause Mold and Mildew

Moisture is the chief cause behind the growth of mold and mildew. Mold spores in the home are inevitable; this is difficult to stop. But you can prevent the factors that help mold and mildew to grow. Besides moisture, lack of sunlight, poor ventilation, and dirt and debris can cause mold and mildew to grow. Because of this, mold and mildew tend to develop in the home:

• In crawl spaces
• Around showers and bathtubs
• In ceilings, near exhaust fans or recessed lights
• In or near areas where water is dripping (drainpipes, gutters, etc.)
• In the wall near the clothes dryer vent
• Near HVAC vents
• Under carpeting
  

How to Prevent Mold and Mildew

• Keep things clean.
• Increase ventilation in the affected area with exhaust fans.
• Install dehumidifiers to reduce humidity.
• Ensure that sources of natural ventilation, such as windows, remain open, if possible.
• Ensure that mechanical venting sources, such as HVAC vents, remain open and unblocked.
• Inspect vents for clothes dryers and ensure that vents are clean and that they are attached.

How to Treat Mold and Mildew

Before cleaning mold and mildew, always wear breathing protection, waterproof gloves, and eye protection. Use a mild detergent with water or a combination of vinegar and water with a new sponge.

1. Remove or Dispose of Unwanted Material

   Remove and dispose of moldy or mildewed wallpaper, rotted drywall, wood, and fabrics.

2. Mist With Clean Water

   If mildew or dry mold is present, mist the remaining area with a squirt bottle filled with clean water to prevent the spores from being released into the air.

3. Mist With Soapy Water or Vinegar Solution

   Mist the area with lukewarm soapy water or the vinegar-water solution.

4. Rub off Mold or Mildew With a Sponge

   • Wipe away the mold and mildew with a sponge.
   • Frequently change the water and use fresh sponges. Old water can redeposit mold or mildew spores in the same area.

5. Let the Area Dry

   Let the area thoroughly dry for at least 48 hours before using the area again.