Mold or Mildew – How Do You Know?

Mold growth is more likely than mildew in your house

Mold on interior wall.

As a young parent, one morning I pulled back the curtain in my baby’s newly decorated nursery to find black furry spots covering the window frame. The question of mold or mildew did not apply here; this was definitely mold growing undetected on the wood frame of a damp single pane window. The warmth of the sun on the window and moisture from my too-frequent use of a humidifier provided its favorite conditions. It couldn’t have been happier.

I was staring in disgusted shock at what is commonly referred to as “black mold” (Stachybotrys Chartarum).  But not every patch of mold or mildew encountered is so easily identified. There are in fact thousands of types of mold in the United States and hundreds of thousands of types worldwide.

Mold grows on dead organic materials

Heavy mold growing in wallboard.
Drywall contains cellulose, a plant fiber, which is a favorite food for mold.

The difference between mold and mildew is best determined by the substance on which it grows. A general rule of thumb makes for easy determination:  mold grows on dead materials that were once alive. These materials include wooden framing or sheathing in the attic, drywall under the sink, underneath bathroom vinyl or just about anywhere in your home. It can grow on dead leaves in a crawl space, leather furniture left sitting on a damp carpet and even on natural fibers such as cotton and wool garments.

Powdery mildew on the other hand, generally grows on living organisms – plants. Powdery mildew looks like its name: it has a white appearance and spreads in a flat pattern. It’s not typically found indoors except on houseplants.

Mold and mildew growth should not be allowed in your home

Mold growth discovered on wall and floor after moving appliance.
It’s possible to have mold growing behind cupboards and appliances and not be aware of its presence.

Of course, whether it’s mold or mildew isn’t usually critical to determine. Both have the same undesirable characteristics of maturing to the point of releasing viable spores. When these spores are inhaled, they may cause negative effects on those allergic to the substances they emit. Both will spread if proper conditions continue. And both should be removed to maintain the health and integrity of your home. Click here to read more about mold’s effects on your home and health.

Mold requires specialized cleaning techniques

Crew member in hazmat suit applying mold serum to interior sheeting
Large areas of mold removal require professional equipment and safety gear.

For more information on mold and how to clean mold yourself, The Centers for  Disease Control and Prevention provides excellent information. Or, if you already know you have a bigger job than you can handle and are wondering how much it costs to get mold removed, contact us. We are mold and mildew removal experts.

If it is necessary to determine the type of mold or mildew present in your home, or how to test for mold toxicity, ServiceMaster by Roth can help. Contact us.