What Does Black Mold Look Like? How to Spot It Early

In the damp Pacific Northwest, mold is a fact of life — but that doesn't mean you should ignore it. Knowing what black mold looks like (and what it smells like) helps you catch a problem before it spreads through your home.

What black mold looks like

So-called "black mold" typically appears as dark green to black patches with a slightly slimy or fuzzy texture. It often shows up in damp, humid areas: bathrooms, basements, crawlspaces, around windows, under sinks, and anywhere there's been a water leak. It can also look dark gray or have a greenish tint depending on the surface and moisture level.

The smell is often the first clue

You'll frequently smell mold before you see it — a persistent musty, earthy, or damp odor, especially in a closed-up room or near a past leak. If a space smells musty but looks clean, mold may be growing out of sight: behind drywall, under flooring, or inside a wall cavity.

Why it matters

Beyond the stain, mold indicates a moisture problem — and it can affect indoor air quality, particularly for anyone with allergies or respiratory issues. Mold also spreads: left alone, a small patch becomes a big remediation job.

When to call a pro

Small surface spots on a hard, non-porous surface can sometimes be cleaned. But if you see mold larger than about a square foot, it keeps coming back, or it's on porous materials like drywall or carpet, it's time for professional remediation. Northwest Restoration is licensed and certified for mold remediation — we find the moisture source, contain the area, remove the mold safely, and fix what's feeding it so it doesn't return.