Look for uninsulated exterior windows and walls, including uninsulated closets along exterior walls where mold can grow when you run your heating in the winter. [substeps] Check the airflow in your home.
[header] How to troubleshoot mold on interior walls [title] Examine areas with excessive moisture. [step] Check your home for sources of excessive moisture. These include flooding, water leaks, damp basements, hvac duct systems or shower or cooking steam.