Here are a few images I took while conducting a Home Energy Performance Survey yesterday. They were taken while the house was depressurized to CFM50. They were taken at the ceiling/wall intersections in the front bedrooms (2nd floor). The wall area is underneath soffit vents and there were no insulation baffles in the attic. In addition, the top plates were not sealed.
There thermal patterns seem to indicate that it’s wind washing from the lack of air sealing and baffles, but they also appear to have patterns associated with moisture. I measured the wall with both a surface and pin type moisture meter - no detectable readings.
My first inclination is to say wind washing as there was an enormous amount of air movement through the attic and conditioned space. But, the patterns have me second guessing myself. Another scenario would be residual moisture stains from ice daming or condensation. It’s probably both! The Delta-T was extremely low (4 Deg F).
Anyways, thought I would post them here and get any feedback.