Mold on Common Building Materials

Mold can grow on just about any surface — but how it grows, and how dangerous it becomes, depends on the building material.

Some materials allow mold to dig deep, others only support surface-level growth. On this page, you'll learn exactly where mold grows most often inside homes — and get links to deeper guides for each specific surface.

Use the quick links below or scroll to learn more about each type of material.

🧪 Want a broader understanding?
👉 See how to detect mold
👉 Explore mold types & colors

🧭 Quick Navigation

• Drywall
• Inside Walls
• Baseboards
• Plaster
• Ductwork
• Windows
• Floors
• Basements
• Attic Insulation

🔍 Mold Detection by Material

🟤 Drywall

Drywall is the #1 most mold-prone material. Its porous paper face is a food source for Stachybotrys chartarum (toxic black mold).
👉 Learn how to identify and remove mold on drywall

🟤 Inside Walls

Mold hidden inside wall cavities is often caused by roof leaks or plumbing issues and can go undetected for months.
👉 Find out how to spot mold inside walls and what to do about it

🟤 Baseboards

MDF and wood baseboards often harbor mold behind them, especially when water gets trapped between the trim and the drywall.
👉 Here’s how to check for and clean mold on baseboards

🟤 Plaster

Mold won’t feed directly on lime-based plaster, but can grow on the paint, dust, or glue on its surface when exposed to moisture.
👉 Learn what to look for and how to handle mold on plaster

🟤 Ductwork

Mold can grow inside HVAC ducts or on the outside due to condensation. This can spread spores throughout your home.
👉 Discover the risks and solutions for mold on ductwork

🟤 Windows

While mold doesn’t grow on glass, it commonly appears on wood frames, caulking, or sills where condensation collects.
👉 Learn how to detect and clean mold on windows

🟤 Floors

Wood, laminate, carpet, and even concrete can harbor mold after water damage. Some molds here may release mycotoxins.
👉 Get expert advice on dealing with mold on floors

🟤 Basements

Basements are ideal environments for mold due to humidity, poor airflow, and foundation leaks.
👉 Here’s how to prevent and detect mold in basements

🟤 Attic Insulation

Fiberglass insulation doesn't grow mold, but the paper backing and wood around it will if there’s a roof leak or poor airflow.
👉 Learn how to spot and deal with mold on attic insulation

🛠️ Not Sure What You're Dealing With?

If you're unsure what material you're seeing mold on — or how far the problem goes — get help now:

👉 Explore the Mold Inspection Guide
👉 Explore the Mold Remediation Guide