What Causes Mold Growth (and How to Prevent It)

Mold needs one thing above all: moisture. Here's what causes mold growth — and how to help prevent it.

What causes mold growth

• Leaks from roofs, pipes, or appliances
• Flooding or water damage not fully dried
• High humidity (above ~60%)
• Poor ventilation trapping moisture
• Condensation on cold surfaces

How to help prevent mold

Control moisture

• Fix leaks promptly
• Use exhaust fans in kitchens and baths
• Keep indoor humidity between 30–50%
• Vent dryers fully to the outside

Improve airflow

• Don't block supply or return vents
• Allow space between furniture and exterior walls
• Service ventilation systems regularly

When prevention isn't enough

If mold appears, removing it without fixing the moisture source guarantees it comes back. See our Mold Inspection & Mold Removal services to address both.