Mold Vs. Mildew: Do You Know The Difference?

By Stefan Gheorghe

| Published on May 19, 2025

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Mold and mildew are both fungi that thrive in moist environments like bathrooms, basements, and around leaks. Though often confused, they differ in appearance, growth behavior, risk level, and how they should be removed.

Feature	Mold	Mildew
Texture	Slimy or fuzzy	Dry, powdery or fluffy
Color	Black, green, brown, red, orange, etc.	White, gray, light green, or brown
Growth Pattern	Grows deep into surfaces (porous materials)	Surface-level growth
Health Risk	Moderate to severe	Mild to moderate
Odor	Musty, pungent, earthy	Musty, sour, less intense
Cleaning Difficulty	Harder to remove; may require professionals	Easier to clean with household solutions
Common Areas	Walls, ceilings, insulation, carpets	Shower walls, windowsills, damp fabrics
Damage	Can cause structural damage	Rarely causes structural damage

Mold

Mold is a multicellular fungus that grows into surfaces through root-like filaments called hyphae. It appears in many colors black, green, orange, pink, and more.

Some types, like black mold (Stachybotrys chartarum), produce harmful toxins linked to respiratory and neurological issues.

It thrives on damp materials like drywall, wood, insulation, and carpet, spreading in dark, poorly ventilated spaces where moisture is present.

Mildew

Mildew is a surface-level fungus with a flat, powdery look. It’s usually white, gray, or light brown.

It’s less harmful than mold but can still trigger mild allergic reactions.

Common in moist areas like showers, kitchens, and laundry rooms, mildew appears as dusty or chalky spots on hard surfaces or fabrics.

Can You Identify Mold Type by Color?

No. While mold can appear in many colors, color alone doesn’t determine the species or risk level. Mold appearance changes based on moisture, light, food source, and age. Only lab testing or a certified inspector can confirm the type.