Several types of mold are common in the Northwest and can be toxic and dangerous if found in your crawl space or attic. Here’s a rundown of various types of molds and some steps you should take if these are found in your home.

types of mold in a home

Have you noticed a strange tinge on your walls?

That’s not what they’re supposed to look like, you know. Mold is an unfortunate consequence of high humidity, bad ventilation, and water leaks. Often, it pops up quickly and quietly. Usually, it’s fairly unharmful, but if left for too long, it can become a major concern to the inhabitants of your home.

So, how do you know when you’ve got mold? And what are the different types of mold that you need to worry about?

In this article, we’ll outline the 10 types of mold that you need to make yourself aware of what can happen if you’re not.

10 Types of Mold Commonly Found in Homes

1. Acremonium

Let’s start with a dangerous one. Acremonium mold is toxigenic and evolves in appearance over time. You’ll notice Acremonium in household systems as well as near humidifiers, window sealants, cooling coils, and drain pans.

It begins as a small moist mold then grows into a powdery substance that can appear pink, grey, orange, or white.

If you’re exposed to this mold, it can have extremely dangerous effects. Acremonium exposure can lead to disease in bone marrow, in the immune system, and other organs. And, it can have effects on your brain function because it’s a carcinogen. Basically, if you notice this, get help.

2. Alternaria

Alternaria is what you probably picture when you think about mold. It’s that velvet textured dark green or brown mold. It grows in showers, bathtubs, and below sinks; anywhere moisture or water damage occurs. That’s why it’s got the distinction of being the most common type of mold in the world.

This mold spreads fast, as you may know, and it’s an allergenic mold that often causes asthma-like symptoms in those touched by it.

3. Aureobasidium

Aureobasidium is another allergenic mold. It’s usually hiding behind wallpaper and painted wooden surfaces, and should not be touched. If it is touched, it can cause infections of the eyes, skin, and nails.

You’ll know this one from its distinctive pink, brown, or black color. As it’s left, it becomes a darker brown. It’s always good to check behind wallpaper and wooden trim when you move into a new house to look for Aureobasidium.

4. Aspergillus

Aspergillus is a common mold in American homes. It’s known for long flask-shaped spores that can get quite thick. There are over 180 types of Aspergillus, so it comes in many different colors, making it hard to decipher.

It’s an allergenic, but depending on which species you’ve got and where you’ve got it, it can become toxic. Usual symptoms when Aspergillus gets bad are lung infections, asthma attacks, and respiratory inflammation. In rarer cases, species can produce deadly carcinogens.

5. Chaetomium

Another common type of mold, Chaetomium is the one kind of looks cotton-textured. Throughout its life, it'll change from white to grey to brown, and then black. You'll find it in water damaged areas of the house like around a leaky roof, in your basement, or under your sink.

It can cause skin infections, but it's particularly dangerous for people with weak immune systems. You can stop Chaetomium from growing by keeping a constant eye on potential danger areas and fixing damage from moisture promptly.

6. Cladosporium

Cladosporium is slightly different from other allergenic molds as it can grow in both warm and cold conditions. You'll find this mold in upholstery and carpets, or under floorboards and cupboards. It's recognizable by its suede looking texture.

This mold, while not considered overly dangerous, can cause infections of the eyes, nose, throat, and skin. At it's most dangerous, it can cause lesions, lung infection, and sinusitis.

7. Fusarium

Like Cladosporium, Fusarium is also capable of growing and spreading in cold temperatures. It's the type of pink mold that you see on rotting food and compost but does grow on wallpaper, carpeting, and other fabrics sometimes.

Minor exposure to Fusarium causes skin infections and allergic reactions like running nose, itchy eyes, and sore throat. If you're exposed to Fusarium for an extended period of time, it can cause much more serious health problems, such as bone infections and brain abscess, both of which can be life-threatening.

Fusarium spreads quick, so if you notice it in one place, check the whole house.

8. Penicillium

Penicillium or penicillin mold is another classic looking mold. It's known for its greenish-blue color and velvet texture. It can be found in water damaged areas and in wallpaper, ducting, and mattresses.

Exposure to this mold can cause respiratory issues like asthma and even pulmonary inflation. If it's not eradicated, it spreads and can cause health complications in people with weak immune systems.

You may recognize the name penicillin from the antibiotic, but when exposed to it indoors for long periods of time, it can cause a lot of problems.

9. Stachybotrys

Aka "black mold". Stachybotrys is that slimy looking greenish-black mold that grows on wood, cardboard, paper, or wicker and in prolonged areas of high humidity.

Exposure to black mold can lead to difficulty breathing, sinusitis, fatigue, and even depression. Severe exposure can lead to painful headaches, nosebleeds, and chest tightness. If children are exposed to it, it can lead to pulmonary bleeding and neurological problems.

10. Mucor

Mucor grows around HVAC systems and ducting due to the condensation. It's known for its grey spores and can cause or worsen asthma symptoms.

Rare cases have seen Mucor exposure lead to a fungal infection called Mucormycosis. This can damage the lungs, sinuses, brain, and can become systemic in the blood and digestion systems if not treated quickly.

Different Types of Mold Lead to Different Problems

It's safe to say that none of these types of mold is good for your home or your family. The way to deal with your mold problem is to attack it swiftly and professionally. At Crawl Pros, we can promptly take care of the mold problems in your crawl space and other water damaged areas of your home.

​Contact Crawl Pros today for ​help in identifying mold in your home.


Our professional estimators can see you in as little as a day.


Give us a call today at 866-673-9626

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