Chaetomium Mold: The Hidden Danger After Water Damage

Most homeowners know to worry about mold after a flood or leak—but they may not realize that some of the most destructive types of mold grow behind the scenes, inside walls or under carpets. One of the most commonly overlooked yet serious molds in water-damaged properties is Chaetomium (pronounced key-TOE-mee-um).

If your home or business has suffered a roof leak, plumbing failure, or flooding, you need to know about this mold—and why it’s a red flag for more than just allergies.


What Is Chaetomium Mold?

Chaetomium is a cellulose-loving mold commonly found in buildings that have suffered water damage. It thrives on materials like drywall, wallpaper, carpets, wood, and insulation—basically anything organic that stays damp for too long.

Unlike many molds that grow in visible patches, Chaetomium often hides inside walls or under floors, growing undetected until serious damage occurs.


Where Does Chaetomium Grow?

Chaetomium needs high moisture and cellulose to grow. It’s commonly found in:

  • Drywall after roof or pipe leaks
  • Carpet padding and subflooring
  • Basement walls and foundation leaks
  • Behind wallpaper or paneling
  • Attics and crawlspaces with poor ventilation

Its presence often indicates prolonged moisture exposure—and sometimes deeper structural issues.


Health Risks Associated with Chaetomium

While Chaetomium isn’t as notorious as Stachybotrys (black mold), it can still cause a range of health issues, especially in people with:

  • Asthma or respiratory sensitivity
  • Weakened immune systems
  • Allergies or chronic sinus infections

Exposure to Chaetomium spores may lead to:

  • Persistent coughing or sneezing
  • Skin and eye irritation
  • Headaches or fatigue
  • Neurological symptoms in severe or long-term cases

In rare situations, certain species of Chaetomium have been associated with opportunistic infections in immunocompromised individuals.


Why Chaetomium Indicates Bigger Problems

One of the biggest concerns with Chaetomium is that its presence often means there’s been significant, ongoing water damage. By the time it’s detected, building materials may already be compromised.

It’s also commonly found alongside other toxic molds like Stachybotrys and Aspergillus, which makes accurate identification and complete remediation critical.


How to Detect and Remove Chaetomium Mold

Chaetomium is difficult to identify without laboratory testing. That’s why professional mold inspection is the safest first step after water damage.

At MSI, we conduct:

  • Air and surface mold testing to identify the type and severity of mold
  • Moisture mapping to find the source of dampness
  • Containment and HEPA air filtration to prevent cross-contamination
  • Safe removal of affected materials followed by antimicrobial treatment

Because of its hidden nature and aggressive growth, Chaetomium cleanup should never be DIY.


Water Damage? Don’t Wait for Chaetomium to Appear

If your property has experienced flooding, leaks, or high humidity, don’t assume the problem is gone just because surfaces look dry. Hidden mold can begin growing within 24–48 hours of water exposure.

The sooner it’s identified, the easier and safer the cleanup process will be.


Schedule a Mold Inspection with MSI Today

At MSI, we’ve been inspecting and remediating mold since 1998. Our certified team has seen thousands of water-damaged buildings and knows exactly what to look for—even the mold you can’t see.

Call us at 877-712-1600 to schedule a professional mold inspection and protect your home, health, and investment.

What is Chaetomium? And How This Mold Can Affect You

When most people think of indoor mold, black mold (Stachybotrys) usually comes to mind. But there’s another aggressive mold species that’s often overlooked and just as dangerous: Chaetomium.

This lesser-known mold is frequently found in water-damaged homes and buildings, yet few people—even some professionals—know how to identify it or understand the risks. At MSI, we’ve encountered it time and time again during inspections, often in places the average homeowner wouldn’t think to check.

What is Chaetomium?

Chaetomium is a genus of mold that typically appears as cottony, white, or gray at first, and then darkens to olive, brown, or black as it matures. It’s often found on cellulose-rich materials such as drywall, wallpaper, insulation, and baseboards—especially after water damage has occurred.

It’s particularly common in:

  • Leaky basements and crawlspaces
  • Water-damaged walls and ceilings
  • Under carpets or floorboards after a flood
  • HVAC systems with trapped moisture

One of the key indicators of Chaetomium is a musty or earthy odor, sometimes stronger than what other molds produce.

How Does Chaetomium Enter a Home?

Like many molds, Chaetomium spores are airborne. Once moisture is introduced—whether through a leak, flood, or high humidity—it can begin to grow on organic building materials. It spreads quickly in damp conditions and thrives in environments that remain wet for extended periods.

Failure to properly dry and remediate a space after water damage often leads to Chaetomium growth alongside other mold species.

Health Risks Associated with Chaetomium

This mold isn’t just an eyesore—it’s a health hazard. Studies have linked Chaetomium exposure to a variety of health issues, particularly in individuals with existing respiratory problems, allergies, or weakened immune systems. Some of the most common symptoms include:

  • Chronic sinus congestion or irritation
  • Skin and nail infections
  • Headaches and fatigue
  • Persistent coughing or wheezing
  • Aggravated asthma symptoms
  • Neurological symptoms in extreme, prolonged exposures

It’s also been found in some cases to produce mycotoxins—harmful substances that can cause cellular damage or immune suppression in sensitive individuals.

Why DIY Mold Cleanup Isn’t Enough

Chaetomium often grows behind walls or underneath surfaces, which means visible mold is just the tip of the iceberg. DIY bleach sprays or quick cleanups won’t solve the problem and may spread spores to new areas of your home.

Professional testing and remediation are critical to identify the full scope of the problem and remove it safely and thoroughly.

Trust the Experts at MSI

MSI has been identifying and remediating dangerous molds like Chaetomium since 1998. With over 10,000 successful mold tests performed and a reputation as a trusted expert witness in mold litigation cases, we know what to look for—and how to get rid of it for good.

If you’ve experienced water damage or notice a musty odor in your home, don’t wait. Contact MSI today for a professional mold inspection and take the first step toward a safer, healthier home.