Finding Uneven Attic Insulation using a Thermal Camera

One of the easier defects to discover using a thermal-imaging camera during a home inspection is the uneven distribution of blown-in attic insulation. Understandably, installers tend to miss areas next to the eaves. And, almost invariably, there is no insulation or weather-stripping on the attic access door / panel.

​A thermal camera captures infrared radiation (heat) emitted from objects and turns that into a colorful image in a process called thermal imaging. The usual custom is that red/yellow/white is hot and blue/purple/black is cold, but any coloring scheme can be applied. The greater the difference in apparent temperature between objects, the more detail that is captured in the thermal image and the easier it is to discover anomalies within a house that you cannot normally see with a normal camera or naked eye, such as: problems with attic insulation, water leaks behind drywall, air leaks through door and windows, electrical circuits that are hot, pest infestations behind walls, and so forth. We can discover these things when the insulation, air, water, electrical circuit, pest, whatever, causes the adjacent walls or floors to heat or cool relative to other areas that will then show up on the thermal image.
 
That attic insulation works well becomes immediately apparent when using a thermal camera. Any attic / ceiling location that it is missing or lacking in insulation can be 10 to 15 degrees cooler or warmer, by my experience, depending upon whether the house is being heated or cooled inside at the time and generally shows up readily using a thermal camera under those conditions.
 
I typically report the uneven distribution of attic insulation as a minor problem, because the fix is relatively straight-forward. The homeowner or handyman, depending upon their skill level and aptitude, could likely venture in the attic with a garden rake to re-distribute the insulation more evenly, knowing in advance where the problems are by the thermal images. Of course, navigating through attics is hazardous and it is always advised to use qualified professionals.
 
How much energy is lost by the missing or low-density areas of insulation? That is hard to quantify. What is clear though is that those low areas of insulation are steadily working against if you trying to keep your energy bills in check and the fix is relatively easy.