What Does Black Mold Look Like? Color and Texture

What does black mold look like? It usually shows as dark green-black or black patches or speckles, often slimy when wet and powdery when dry, on materials that stay damp, such as drywall paper, ceiling tiles, wood and grout. But many molds are dark, and you cannot tell species by color, so a lab or professional is needed to be sure.

What does black mold look like: the visual clues

People use the term black mold for dark molds, and often for one species, Stachybotrys chartarum. It tends to grow on cellulose-rich materials such as paper-faced drywall, wood and ceiling tiles that stay wet for days. Look for spots, streaks or clusters that spread over time, with a rough or slimy surface and a musty smell.

Quick facts: what does black mold look like
Color	Black, very dark green or gray-black; sometimes with white or olive edges
Texture	Slimy or glossy when wet, powdery or sooty when dry
Pattern	Round spots that merge into larger patches or streaks
Common places	Behind wallpaper, under sinks, on ceilings, around windows, in basements

Colors and textures of common molds

Mold look	Often seen as
Black or dark green spots	Stachybotrys and many other dark molds
Green and blue fuzzy patches	Common indoor molds on food and walls
White cottony threads	Early growth or some species on wood and basement walls
Orange, pink or yellow patches	Various molds and bacteria on damp surfaces
Gray or brown dusty film	Older growth or dust-covered mold

Where black mold hides

1. Behind the paper facing of drywall near leaks.
2. On the back of ceiling tiles and under carpet padding.
3. Under sinks, around dishwashers and behind washing machines.
4. In basements, crawl spaces and attics with condensation.
5. Around window frames and shower walls that stay wet.

Mold, mildew, dirt or stain?

Dirt wipes off easily and does not smell. Mildew is usually flat, gray, white or yellowish and sits on the surface. Mold grows into materials, spreads in patches and smells musty. Try wiping a small spot with a damp cloth wearing gloves: if it smears and returns, treat it as mold.

Why color is not proof

Many molds are black, green or gray, and the same mold can look different on different surfaces or at different ages. Health agencies say that you cannot identify the species or its health risk by sight, and that any indoor mold should be removed. Testing for species rarely changes what you must do.

What to do if you find it

For a small area under about 10 square feet on a hard surface, you can clean it with detergent and water, wearing gloves, goggles and a respirator, then dry the area. Do not dry-brush or sweep it, and do not paint over it. Fix the water source first. Discard porous materials that are moldy.

Signs of a bigger problem

Large patches, mold in several rooms, a musty smell without visible growth, peeling paint, warped or soft walls and recurring symptoms such as coughing or irritated eyes at home suggest hidden moisture. Do not cut into walls yourself if the area is large.

Early signs to watch for

Before patches turn black, you may see a slight discoloration, a faint dotted pattern, a damp or cool feel on a wall or a bubble under paint. Wallpaper that lifts at the seams, paint that cracks in a map-like pattern and wood that darkens at the edges are all early hints. Catching it at this stage is how you avoid cutting out a whole panel. A quick look under sinks and in corners each month is a simple routine.

When to call a professional

If the mold covers a large area, returns, or is behind walls or after flooding or sewage, call a mold remediation company. Knowing what does black mold look like helps you spot trouble early, but the response is the same for any indoor mold: find the water, dry it and remove the growth.

Related reading

• Black Mold vs Mildew: How to Tell Them Apart and What to Do
• Mold After Water Damage: How Fast It Grows and What to Do
• Mold Under Kitchen Sink: Find the Leak, Clean It, Stop Regrowth
• Does Homeowners Insurance Cover Mold? What Policies Usually Say

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