I have recently been adding more insulation to our attic because our house is unable to cool to 75 degrees when it's 83 degrees outside. My thermal gun is reading 66 degrees from the vent when the A/C is set to 76 degrees. I've been told that the A/C being pushed out should be 20 degrees cooler than the intake. Is this true? Anyway, I've added blown insulation to the attic and went around the attic with the thermal gun in to find cold leaks coming in from the interior of the house. Most of the air leaks I found we're easily blocked with Great Stuff, but I found a place in the attic where the floor is cold (see attached picture). The floor is sealed up tight, but when I put the thermal gun to it it reads 80 degrees and the attic temp was reading 94 degrees. I'm sure there isn't any insulation underneath and I'm not sure how to tackle this. I'm open to any suggestions.