How to avoid, detect and clean up mold in your house

By learning about the types and causes of mold, you can take steps around your home to prevent mold problems before they become chronic.

Tags: Home improvement, Home, Be prepared
Published: February 11, 2019

Household mold is a naturally occurring fungus — as well as a scourge of homeowners.

With mold, airborne spores settle and grow in warm, damp places such as bathrooms, basements and water-damaged walls. Mold has a distinctive musty odor, and you might smell it before you see it. It has a thickness to it, looks fuzzy or slimy and comes in a wide variety of colors.

Some individuals experience allergic reactions to mold, including coughing, wheezing, runny nose, red eyes and skin rashes.

Types of mold

These are the four common varieties found in homes:

  • Cladosporium: Characterized by a small black clump.
  • Penicillium: A fuzzy green, white or blue growth.
  • Alternaria: A velvety dark fungus that needs less moisture than other types.
  • Aspergillus: Hundreds of different strains in varying sizes and colors. This particular fungus is most dangerous to individuals with compromised immune systems and can infect the lungs, sinuses and other parts of the body.

Where you might find mold

Your bathroom is a common location for mold, with cladosporium growing above the waterline in toilet bowls. On shower walls that aren’t cleaned regularly, you’ll often find alternaria. In the kitchen, mold is primarily found on old food. This is penicillium; food with mold should be thrown out, but no other steps are needed.

The more insidious types of mold are usually found in places you don’t necessarily expect. Alternaria, because it needs less moisture than most molds, can grow on or under wallpaper as well as within carpeting in damp rooms. It can also grow in walls that have a plumbing leak or condensation drips.

Aspergillus, the most dangerous of the common molds, thrives in areas of major water damage, either from flooding or a significant chronic plumbing leak. It can be found between or behind walls and ceilings, and thus often isn’t visible from the living area of your home.

How to prevent mold in your house

First identify the primary source of the mold problem:

  • If caused by a plumbing leak, repair and clean up. Make sure your fix is permanent.
  • If caused by significant flooding, correct the problem, repair the water damage and take steps to prevent future flooding.
  • If caused by an excessively damp environment, buy a dehumidifier to keep humidity levels below 50 percent at all times.
  • If caused by a foundation issue, take steps to ensure that water flows away from the foundation of your home.

Other steps you can take include the following:

  • Insulate pipes to prevent condensation.
  • Do not carpet bathrooms or basements.
  • Regularly ventilate bathrooms, kitchens and basements.
  • Clean air conditioner drip pans.
  • Keep roof gutters clear and in good repair.

How to remove mold

Even if you know how to prevent mold in your house, you may need to first remove an existing problem.

The Environmental Protection Agency (EPA) issues guidelines on proper mold removal. In general, individuals can safely scrub affected areas that are less than 10 square feet with bleach or detergent. Remove items like ceiling tiles that can’t be easily cleaned and take care to protect yourself by using the following equipment:

The EPA recommends that you seek professional assistance for larger areas or areas that have suffered extensive water damage. A contractor’s qualifications should include:

  • Experience in mold removal
  • Adherence to professional guidelines
  • A remediation license or certification (varies by state)

Your home is one of the most valuable assets you have. Prevent mold in your home to protect against allergens. It’s for the health and safety of everyone living there, now and in the future.


Learn more about how you can protect the investment in your home.


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