Mold Vs. Mildew

Mold. Mildew. These terms are often used interchangeably and can be very confusing to people. So let’s clear the air shall we? What is the difference between mold and mildew and why should you care?

Mold Vs. Mildew – What Is Mold?

Molds are organisms which are neither plant nor animal. They are part of the fungi kingdom. Molds also digest or “eat” the material they are growing on. The role of mold is to break down decaying organic matter such as dead plants, leaves or dead animals.

Mold is found both indoors and outdoors but is considered most dangerous when found growing indoors. There are hundreds of thousands of species of mold ranging from toxic, to allergenic, to pathogenic.

Mold needs moisture, oxygen, a comfortable temperature, and a food source to grow.

For more information about the basics of mold, please check out my Mold Facts page.

Mold Vs. Mildew – What Is Mildew?

According to the Federal Emergency Management Agency (FEMA), mildew is considered to be early-stage mold. In it’s simplest form, this is true.

Primarily, mildew is a plant disease that causes great damage to crops and plants. It is classified as powdery and downy:

• Powdery mildew mainly affects flowering plants and first appears as white or gray patterned splotches that gradually become yellowish brown or black as the fungus grows.
• Downy mildew is commonly found in agricultural products, such as grapes and potatoes. Its appearance varies depending on the type of surface it grows on, but usually downy mildew starts as yellow spots that eventually turn brown.

Just because it tends to gravitate towards plants doesn’t mean you can’t find mildew indoors. It can grow on any organic material inside your home. Paper, leather, wood, ceilings and floors are just a few of the surfaces that support mildew.

How Are Mold and Mildew The Same?

Both mold and mildew are types of fungus that thrive in moist, humid conditions where a light source is either poor or non-existent. Both grow when spores or seeds find their way into suitable environments for colonies to grow. Both mold and mildew need porous, organic material to grow on (ie. wood, fabric, paper, clothing, drywall, insulation, carpet, wicker, mattresses, padding, upholstery, foods, etc.)

How Is Mildew Different From Mold?

First, mildew is a type of mold, but not all molds are mildew. In addition, mold can grow on synthetic materials (ie. tile, plastic, most metal-based products, etc…) while mildew cannot.

From there, the main differences between mildew and mold are appearance.

Mildew usually grows in a flat pattern and appears either powdery or fluffy. It can be easily identified as a patch of white, gray, or yellowish fungus that is lying on the surface of a moist area. Mildew usually turns black or brown over time.

Mold is usually fuzzy or slimy in appearance. It appears as irregularly shaped spots that can have over 13 different colors. Mold can take over a surface area quickly and cause a lot of damage.

Which is Worse – Mold or Mildew?

Mold. Mold is absolutely worse.

Mildew usually affects plants and crops. If it develops indoors, however, it can also pose health risks. When inhaled, mildew spores cause coughing, headache, sore throat, and respiratory problems.

Mold can result in considerable structural damage when left unattended for a long time. Prolonged exposure can cause a variety of health problems, depending on the strain of mold. The mycotoxins produced by several species of mold are particularly harmful and may have severe long-term health effects.

Yet another difference of mold vs. mildew is how difficult it is to get rid of each fungus. With mildew, all it typically takes is a mildew cleaner, a good scrubbing brush, and some elbow grease. However, mold is not an issue that most people should be dealing with on their own. Mold removal is best left to professionals.

How do I know if it’s mold or mildew again? To recap, the main differences between mold and mildew generally are:

• The texture
• The color
• The stage of growth
• The severity of possible health risks posed by each
• The type of home damage they can cause

Remember, if you are in doubt as to whether you have mold or mildew, consider doing some DIY mold testing or consult with a reputable mold inspector.