What Causes Mold Growth Indoors
Mold spores are everywhere — outdoors and indoors. What turns harmless spores into a problem is moisture. Understanding the main moisture sources is the first step in prevention.
Plumbing leaks
Hidden supply-line, drain, or fixture leaks are a leading cause of indoor mold. Even small drips can saturate cavities over time.
Roof and envelope intrusion
Storm damage, failed flashings, and clogged gutters allow water to enter attics and wall cavities.
Condensation
Cold pipes, windows, and HVAC ducts collect moisture from warm indoor air. Without insulation, that moisture builds.
High indoor humidity
Indoor RH above ~60% for sustained periods supports mold growth on porous materials.
Poor ventilation
Bathrooms, kitchens, and laundry areas without proper exhaust trap moisture indoors.
Related Services
Have a concern? Our inspectors are here to help.
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