Thermal bridging occurs when materials with lower thermal resistance (like wood studs or metal framing) create colder areas on the interior surfaces of walls and ceilings.
When warm, humid indoor air touches these cold areas, it can cause moisture (condensation) to form. Over time, dust and soot adhere to moisture, creating dark streaks or stains on walls and ceilings—often referred to as “ghosting.” High humidity, poor ventilation, and indoor activities such as smoking, cooking, or burning candles can exacerbate the problem.
In the video below, I use a thermal camera to identify missing insulation. Over time, the walls in the family room began to collect dust and debris. This is more common in the winter months in Mississippi.