How To Identify Black Mold

Black mold can be harmful to the home and hazardous to your health. Learn how to identify black mold so you can eliminate it.

By Lauren Wingo | Updated May 24, 2022 3:00 PM

How to Identify Black Mold


There are various types of mold in nature, many non-hazardous, but mold is not something anyone wants to see inside the home. Experts say diseases like toxic mold syndrome have no basis in science and are just media hype; however, mold can cause reactions in people with allergies or weakened immune systems when it grows indoors. Black mold (‘Stachybotrys chartarum’) is a variety of mold that can be particularly tough to remove. It feeds on cellulose-rich building material like wood and drywall and can breed in damp areas. Black mold grows quickly, which is why homeowners must learn how to identify black mold as soon as possible.

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Difficulty: Beginner
Estimated cost: $8 and up if using a mold test kit

Before You Begin…

How to Identify Black Mold Tips


If there is a lingering musty smell in the home, or if a household member is experiencing ongoing black mold symptoms such as respiratory issues or allergic reactions, hire a licensed mold inspector to assess the home and test for mold. While it’s possible to learn how to identify toxic black mold yourself, it may be more challenging to identify and remove the mold without proper training.

Tips for How to Identify Black Mold in Your House

  • Black mold feeds on cellulose and usually grows on or near building materials like drywall and wood.
  • Black mold thrives in damp areas.
  • Black mold often grows inside walls first, meaning homeowners can often smell it before they see it.
  • Black mold can grow in air ducts, window sills, the kitchen, and the bathroom–all common sources of collected condensation.
  • Sealants and grout can be vulnerable to black mold. Since they’re usually in high moisture areas such as the shower, it’s crucial to carefully check caulk and bathroom tiles.

Safety Considerations

  • Always wear protective gear when identifying, touching, and cleaning any mold, including coveralls, a protective face mask, safety goggles, and non-porous gloves.
  • Clean and disinfect protective gear and tools once the mold has been assessed. Microscopic spores can linger on surfaces and grow new colonies if contacted surfaces are not adequately cleaned.
  • If large amounts of black mold are present upon inspection, contact a professional mold remover immediately. If a homeowner attempts to get rid of black mold themselves, they may leave mold spores behind, which will cause it to recolonize.
How to Identify Black Mold Inspect the Color


STEP 1: Inspect the color first.

What does black mold look like? As the name implies, matured black mold is typically black, but it may appear in different colors such as dark green, dark gray, or brown before taking on its characteristic black hue.

It’s easy to mistake black mold for dust or dirt. Black mold usually has smaller spore groupings and is condensed to a secluded area. However, if it’s had time to grow in damp conditions, it may travel to different parts of the wall or room.

There are many different strains of mold in varying colors, including white, yellow, or green. Mold that is black can be the same color as black mold and not be the same strain. Black mold refers explicitly to ‘Stachybotrys chartarum.’

STEP 2: Try to find a source of a musty smell.

Homeowners may need to use their noses to sniff out the source of the black mold. Black mold may not have a strong smell if it’s starting to grow. Once it’s matured, black mold will have a robust earth-like smell, similar to dirt or rotting leaves. Established black mold has a more pungent smell than other types of household molds.

STEP 3: Check if it has a wet and slimy texture.

While other types of mold may have a fuzzy, light texture, black mold will usually be slimy or wet. Some early forms of black mold have a powdery feel. Rub the mold with a paper towel to determine the texture, but be sure to wear gloves, a face mask, coveralls, and safety goggles when going near mold.

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Take care not to touch the mold with bare hands or touch your face with any materials that have come into contact with mold. If you do touch black mold with your bare hands, run them under hot water and wash thoroughly with soap as soon as possible.

How to Identify Black Mold Use a Mold Test


STEP 4: Use a mold test kit to confirm the presence of black mold.

Homeowners can confirm mold using a mold test kit, which can be purchased in a home improvement store or online. There are different types of kits available and they may cost as little as $8 or upwards of $300.

While the initial collection only confirms the mold’s presence, samples can be sent to a lab that will determine the type of mold. These additional analyses can run from $40 to $70. While the Centers for Disease Control (CDC) says that it is unnecessary to identify the type of mold present before treating it, the information may help homeowners in case mold returns.

To test for mold, follow the instructions on the test kit. The test will take about five days to confirm or deny the presence of mold. If the presence of mold is detected, homeowners can send the test to a lab for analysis. It can take up to eight weeks to receive the results of the mold type.

How to Identify Black Mold Create a Plan for Cleaning


STEP 5: Create a plan for cleaning and removing the black mold in the affected area.

Once the presence of black mold has been confirmed, clean and remove it. If the black mold is in the early stages or is localized to a small area, it’s possible to remove the mold yourself. With a mold-fighting solution such as tea tree oil, sodium borate, vinegar, or bleach, clean the mold using a nylon bristle brush and old rags or paper towels.

If black mold is extensive or in a hard-to-reach spot, or if you’re concerned about the health hazards, it’s best to contact a mold removal specialist.

These tips will teach you how to identify and how to get rid of black mold. When in doubt, always ask for assistance from a professional to ensure your home is mold-free.

Don't want to do it yourself?
Professional mold inspection may be the answer. Get free, no-commitment estimates from licensed service providers near you.