This is an infrared thermal image of the raised ceiling area of a brand new house. My clients wanted me to inspect it before they did their final walk through. There were a few items that needed to be corrected, but the one that could not be seen with a purely visual inspection was lack of attic insulation. I had been in the attic before taking this photo later when I was back inside the living area. It was only 65 degrees outside but still warmer in the attic enough to show this hot area that shows up in Orange when a thermal image is taken.
I have added the black lines to help one see the walls and the ceiling junction. The insulation sub-contractor did not do a very good job of installing the attic wall insulation. The insulation batts up there were loose and the blow in insulation was sloughing off at the edge of the ceiling. There needs to be an insulation baffle to keep the insulation at the required R-38 all the way to the edge of the flat living room ceiling. This was on a "warm" day in the winter - imaging how much more heat would be radiating from the attic when the Summer sun hits the roof.