The presence of certain molds in large amounts can spell trouble for your home and your health. These days you don’t have to look hard to find stories of mold and the serious problems it can cause in homes. Recently, the U.S. Congress convened hearings to address the presence of high levels of mold in military housing, and the U.S. Centers for Disease Control continues to update its findings regarding the adverse effects of mold on human health.

Mold is a big deal. But should you panic when you find a small patch of mildew in your shower? And what’s going to happen if it grows in your home?

What is Mold? 

To understand and identify mold, it’s important to understand what it is. Mold is a fungus that can grow anywhere. Although it can grow on floors, walls, carpets and appliances, it thrives in warm, moist conditions, which are most likely to be found in areas like the kitchen, basement or bathroom. The issue of mold often accompanies other problems around the home, such as a leaky pipe or broken HVAC system or an extreme case, such as a home that’s suffered from flooding or extreme storm damage.

The purpose of mold in nature is to break down dead trees and plants. This is a good thing and it’s beneficial to our Earth’s ecosystem. But when mold gets inside of a building, it can compromise the structure of the building and the health of its occupants.


Mold travels through the air in the form of “spores,” tiny particles that attach themselves wherever they can land. Once they land in a new spot they begin to multiply. Unfortunately, these spores are small enough that they can be breathed into the human lungs. In small amounts, they don’t typically cause problems. But in larger amounts or in a person who has other health problems, breathing in mold spores can quickly become life-threatening.

People who have a sensitivity to mold may find that exposure to it causes them to experience upper respiratory systems, such as a stuffy nose or wheezing. Or, they may experience irritation on their skin. Mold sensitivity is different than a mold allergy, however. A person who has a mold allergy or is immune-compromised in some way may experience more severe health problems, such as serious lung infections. Although mold can affect anyone, it is most dangerous to adults and children with existing health conditions, such as asthma.

When left untreated, mold can also cause building structures to crumble, ultimately making them unsafe for human occupancy.

Most Common Types of Mold Found in Homes

The idea of mold in your home is enough to make your skin crawl, but don’t start scrubbing everything yet! If you suspect mold is present, take a few minutes to look at what you’re dealing with.

All types of house mold can be divided into one of three categories:

  1. Pathogenic: Types of indoor mold that are more likely to cause health problems in individuals who already have other health issues.
  2. Allergenic: Types of mold that can cause allergic reactions, including upper respiratory symptoms and asthma attacks.
  3. Toxic: Types of mold that produce substances that can cause adverse or even life-threatening health issues.

Although exposure to allergenic molds can potentially be less serious than exposure to the types of toxic mold found in the home, both can still cause serious health problems. In small amounts, it’s relatively easy to clean up, but if you aren’t sure whether a substance is mold or you suspect that it’s present in large amounts, it’s important to call a professional restoration company to assess the situation. They can confirm your suspicions and identify a course of action to quickly address and repair the situation.

But how many types of mold are there?  And which common types of house mold should you be worried about?

1. Alternaria

This rapidly spreading mold is the most common type of mold found in a home. It’s most likely to be found in areas of the home that are prone to dampness, such as underneath sinks, in the shower or around a bathtub, especially if one of these areas has a leaky pipe nearby. Alternaria is known by its velvety texture and is usually green or brown in color.

Alternaria is classified as an allergenic mold, meaning that it causes allergy symptoms that mimic asthma, even if the person reacting to it isn’t asthmatic. Because this mold spreads so quickly, it’s important to address and remove it as soon as its discovered.

2. Aureobasidium

Among mold types found in the home, this allergenic mold is most likely to be found growing on wood or painted surfaces or behind wallpaper. It can be either brown, pink or black in appearance, depending on how long its been growing. The older it is, the darker it becomes.

Although its also classified as an allergenic mold, Aureobasidium is more likely to cause an allergic reaction on the skin. Individuals who are exposed to this type of mold may also experience nail, skin or eye infections.

3. Cladosporium

Unlike some other types of household mold, Cladosporium doesn’t need warm temperatures to thrive. It can be found in warm or cool conditions, and it’s most likely to take hold in carpets or upholstered furniture. You might also find this type of mold residing inside of kitchen cabinets or under flooring. Cladosporium is best identified by its color — olive green or brown — as well as its texture which is reminiscent of suede.

Even though its texture is one of its identifying features, you should avoid touching it if you suspect that this type of mold is in your home. When handled, it can cause serious skin rashes, as well as lung irritation and upper respiratory issues.

4. Aspergillus

This common mold might be tougher to identify because there are many variations of it. Besides appearing in many different colors, it is also known for having long spores that form chains of mold and can quickly cover a variety of surfaces.

Although classified as an allergenic mold, Aspergillus can become a toxic mold, depending on where it forms and which variation is present. This means that it has the potential to cause lung infections and asthma attacks. In some forms, it can also even produce aflatoxins, a type of fungi that has been connected to an increased risk of liver cancer.

5. Penicillin

Yes, this type of mold has certain antibiotic properties when grown in the right conditions, but when it takes hold in the home, it can be the cause of serious health issues. Penicillin is an allergenic mold that can easily be identified by its velvety green-blue appearance. This rapidly spreading mold is most often found in homes that have suffered water damage, especially in wallpaper, carpets, mattresses and even air ducts.

Penicillin spores easily become airborne, meaning anyone in proximity can breathe them in, including pets and children. These spores can cause asthma and pulmonary inflammation and, ultimately, chronic sinusitis.

6. Fusarium

Fusarium is both an allergenic and a toxic form of mold. It grows in warm and cool temperatures and is most likely to be found in carpets or fabrics of homes with water damage. It spreads quickly, so if you suspect that you have it in one room, it’s important to check other rooms of your home as well.

Individuals who are exposed to Fusarium can experience a range of symptoms, including skin infections and upper respiratory issues. Over time, exposure to this form of mold can have serious repercussions on the nervous system, as well as cause internal bleeding.

7. Chaetomium

This mold is often identified by the odor it gives off. When present, it emits a musty odor that can’t be corrected with cleaning or air freshener. Typically found on a leaky roof, basement or sink, Chaetomium varies in color, ranging from white to gray, brown and, eventually, black.

The most common health effects associated with Chaetomium include nail and skin infections. Over time, it may also produce mycotoxins that can be harmful to immune-compromised individuals.

8. Trichoderma

This allergenic mold is typically white with green patches. It grows in small, round clusters. In the home, you’re most likely to find it on fabrics, carpet or wallpaper. It’s also found in HVAC ducts when condensation has built up over time, as well as air conditioning filters.

Some forms of Trichoderma are non-pathogenic, meaning they don’t pose a significant health threat to humans. However, other forms of this mold have been found to contribute to liver and lung infections. Health issues aside, this particular form of mold is known to seriously compromise and destroy building materials. When Trichoderma takes over in a home or other type of building, it can eventually cause parts of the building to crumble and render it inhabitable.

9. Stachybotrys 

This form of mold is the one commonly known as “Black Mold.” Everyone knows enough to be afraid of Black Mold. But what exactly is it? Stachybotrys is a toxic mold known for its slimy texture and dark green or black appearance. It typically thrives in warm, damp areas where it can spend weeks taking hold without being disturbed. It’s typically attracted to wood, paper, hay or cardboard.

Stachybotrys is classified as toxic mold. Among its many health effects, those who are exposed to it may experience breathing problems, fatigue, sinusitis, depression, achy sinuses, chronic cough, headaches, fever and more.

10. Ulocladium

Although this mold is black in color, it’s different than its Black Mold cousin. It’s typically found in rooms and buildings that have sustained significant water damage and windows with high condensation. It often grows together with other types of mold. Because of its properties, this one can be more difficult to identify, so it’s important to call a professional if you suspect this or other types of mold are growing in your home.

Upper respiratory issues or symptoms similar to a hay fever allergy are among the more common symptoms of exposure to Ulocladium.

Where to Find Mold in the Home

Mold thrives in damp locations, meaning it often forms in areas of the home that have experienced water damage or excessive moisture of some kind. In certain cases, such as a flood, it’s obvious where the moisture is coming from. However, in other cases, if you suspect there’s mold growing in your home, you may need to do some sleuthing to find its source.

Wondering how to spot mold in the home? Although mold can technically grow anywhere there’s moisture, there are certain areas of the home that should be checked first.

1. Kitchen and Bathroom

Since mold grows in places where there’s moisture, start in the rooms where you’re using water on a regular basis. Check under the sink, around the dishwasher, as well as in and around tubs and showers. If your house is built on a crawlspace, go under your home and inspect the structure that’s under your sinks and showers as well. If you can’t get under your crawlspace, hire a professional company to come and inspect the space. Besides inspecting your crawlspace for signs of leaks, they can monitor and record moisture levels under your home. Over time, if these levels appear to increase, they can recommend ways to decrease the moisture under your home to prevent mold from growing.

2. Basement and Roof

Besides being dark, basements tend to be damp because they’re underground. In many cases, the pipes for your home may also run through them and, if they’re leaky, they can leak water into your basement. Check walls, ceilings and floors in your basement if you suspect that mold is present. It’s also important to check for different types of mold in the attic and roof, especially if you’ve recently found a leak in your roof.

3. HVAC System

If your HVAC isn’t working properly, it may have excess condensation built up inside of the evaporator coils, drip pan or air ducts. This can lead to mold. When this goes undetected, it can blow mold spores around your home and make your family sick. Depending on the type and amount of mold, you may not be able to diagnose this problem on your own. An HVAC company or mold remediation company can provide a more thorough inspection to determine if this is the case.

4. Interior Surfaces

Many types of mold are attracted to surfaces inside of your home, including walls. Most people know that mold can grow in their showers and tubs, but it doesn’t stick to the bathroom. If your home’s moisture levels aren’t regulated properly or you’ve experienced water damage, mold may begin to grow on walls and flooring. But it’s not just smooth surfaces. Certain types of mold also like carpets and upholstery too.

How to Identify Types of Mold

Often mold is present after a home has sustained serious water damage after a storm or fire. Serving communities around Florida, including Orlando, Tampa, Miami, Naples, Jacksonville and Fort Lauderdale,  Beacon Restoration’s team of experienced home restoration experts can provide diagnosis and restoration services for homes and businesses impacted by storms, fire or other natural disasters. We know firsthand the stress that comes from experiencing a crisis, and our goal is to provide high-quality service and peace of mind so that you can focus on getting back on your feet.

If you are in need of restoration services, get help now. Call (407) 428-1932‬ or request service online.