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4 Types of Dangerous Mold in Your Home

Mold can grow unseen throughout your home in the crawl space, walls, and other areas. Humidity coupled with a lack of air circulation can trigger the growth and spread of toxic mold. It can affect the structural integrity of a home, worsen health issues like allergies and asthma, and ruin building materials, rugs, and furnishings.

These effects of mold illustrate the importance of identifying and stopping mold growth before it starts.

This guide explains the four common types of mold found in crawl spaces and other areas throughout homes, as well as how to identify and safely address them. Learn how our expert team at JES can help with trusted crawl space encapsulation solutions!

Dangerous Mold in the Home

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4 Common Types of Mold & What They Look Like

Mold is common and can be found growing almost everywhere indoors and outdoors throughout the U.S. Mold growing outdoors is natural and plays an important role in a healthy ecosystem. Mold found growing indoors, however, can be a huge problem – to your own health and the structural integrity of your home.

The most common types of mold found growing indoors in the U.S. are listed below. Each of these types of mold can negatively affect the air quality found in your home.

  • Cladosporium grows on moist acrylic-painted walls, wood, carpets, wallpaper, or other damp organic matter. There are 40 different kinds of Cladosporium and they come in many different colors including green, brown, gray, and black.
  • Penicillium is a different type of mold you may have learned about in science class or found in your own refrigerator on spoiled food. It causes food and other perishable items to spoil. Penicillium can also be found growing on walls, wallpaper, floors, and carpet. It can be blue, yellow, green, or white.
  • Alternaria mold often grows on iron, tiles, bricks, plaster, wallpaper, paper, and canvas. There are 50 different types of Alternaria mold, which is a common cause of allergies. Alternaria grows in dark gray spots.

Beware of This Toxic Mold

black mold on concrete wall

The fourth most common and most toxic type of mold found growing indoors is Stachybotrys chartarum. Often called “black mold,” it is a dangerous, toxic mold. Luckily, this type of mold growth indoors is rare. It is most often caused by long-term moisture in a home. For example, a home that has been empty for months without good air circulation or that has a leaky pipe could have toxic black mold.

It is very difficult to identify the difference between black mold and many of the other common types of mold that grow indoors. Toxic black mold is greenish-black in color and can produce a musty or rotten smell, what we think of as a “musty-smelling basement.” It can be found on water-damaged materials that have been damp for longer than 24 hours.

Because it’s difficult to tell the difference between black mold and other types, the Centers for Disease Control recommends removing all mold immediately.

How to Prevent Mold Growth & Remove it from Your Home

Mold can harm your health even if you can’t see it. That’s why it’s important to stop its growth before it starts. The best way to stop mold from growing in your home is to reduce moisture inside the home. 

Remove Excess Moisture

dehumidifier and sump pump in encapsulated crawl space

One of the quickest and easiest ways to reduce moisture in the air is to run an air conditioner during the summer months and add a dehumidifier to rooms where moisture lurks, including the crawl space or other areas without good air circulation. It’s also beneficial to waterproof the crawl space with interior drainage and a sump pump and encapsulate the crawl space with a durable vapor barrier.

If moisture develops inside the home from a leak, open window, or other reason, it’s important to dry any wet areas, including carpets, walls, and furnishings – immediately.

To reduce the chance of water leaking into your home, clean gutters and direct the flow of water away from exterior walls before the spring or summer rainy season. Get your home, including its foundation, inspected regularly for cracks, which can allow water into the home. If you use sprinklers to water plants and lawns, make sure they are not striking exterior walls directly or causing pooling water near the home, which could leak indoors.

Other Indoor Tips

There are many other ways you can help reduce mold growth indoors. Remove carpet from bathrooms and unfinished areas. Run fans to create air circulation in all rooms of the house, especially ones that are underused like guest rooms or storage areas. Don’t overwater indoor plants and clean air vents. Replace air filters regularly to reduce the spread of mold through the air. Cover pipes with insulation to reduce water pooling outside the pipes in the summer months. Clean all bathrooms regularly and remove all standing water, including inside showers and bathtubs. Keeping a clean kitchen, including removing perishable items from your refrigerator and cabinets, is also a good way to reduce mold growth.

Mold Removal

applying mold biocide spray in crawl space

Finally, if you do find mold growing inside, remove it immediately. The first step is to throw away molding food, carpets, furnishings, and other items.

Don’t just paint or caulk over mold in the shower, bathroom, or other areas. Remove it completely with help from mold remediation specialists. Many resources say you can use a variety of cleaning products, but removing mold on your own can be dangerous. Leave it to the pros instead.

Once the mold is removed, identify the cause for its growth and fix the issue, or the mold will just grow back again! That’s where JES can help. We’ll inspect your crawl space, pinpoint the source of the problem, and recommend the best crawl space encapsulation and repair solutions that meet your needs.

Contact JES for Reliable Crawl Space Encapsulation

Mold and your crawl space is a deadly combination. Once it starts growing and spreading, it affects more than just your crawl space; it can negatively impact your health and lead to structural damage. Prevent it from harming your home and family with help from the local crawl space experts at JES.

Our team can help fix current problems and reduce mold growth in the future. To learn more about our industry-leading crawl space encapsulation solutions and how they improve moisture control in your home, contact us today to schedule a free inspection! 

Kathryn Butler

Kathryn Butler

Content Writer

Kathryn is a Content Writer for Groundworks, bringing ten years of professional writing expertise to the home services industry. Thanks to a combination of a passion for research and having lived in several places around the world as a military wife, Kathryn has accumulated valuable insights into the diverse challenges faced by homeowners. Kathryn currently calls Virginia Beach home, where she resides with her husband and three children.

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