Water or moisture in basements comes from two sources.
1. Indoor Humidity: condenses on cold surfaces, much like water droplets form on a cold drink on a humid day.
2. Water or Water Vapor: comes from outside, rainwater, melting snow or groundwater can saturate the soil around your foundation and leak in.
Tip: Tape aluminum foil to your basement wall and inspect it a few days later. Moisture on the outside surface means there’s high indoor humidity, moisture behind the foil means water is leaking through the walls.