Identify the surface
Confirm which side is wet and rule out plumbing, rain entry, or moisture between sealed glazing panes.
Understand window, pipe, bathroom, garage, and whole-home condensation using relative humidity, surface temperature, and dew point.
Condensation appears when a surface reaches the air's dew point. The useful question is not only how humid the room feels, but where the coldest surface is and how much moisture the room is carrying. These guides connect the visible droplets to ventilation, insulation, air leakage, and seasonal conditions.
Confirm which side is wet and rule out plumbing, rain entry, or moisture between sealed glazing panes.
Record room temperature and RH, then estimate or measure the temperature of the wet surface.
Reduce vapor sources and improve ventilation, air sealing, insulation, or circulation as appropriate.
The room can look dry while one cold surface is wet. Dew point explains why.
Read guideUse glass temperature, indoor humidity, ventilation, and window condition to separate normal events from recurring problems.
Read guideConfirm condensation, reduce room humidity, and insulate safely without hiding a plumbing leak.
Read guideA simple test plan to distinguish humid-air condensation from moisture moving through the concrete.
Read guideA practical ventilation check using RH recovery time, mirror clearing, airflow, and fan routing.
Read guideA practical target range for comfort, condensation control, and everyday moisture decisions.
Read guide