I thought it might be fun and helpful for us to share IR photos that led us to discover and/or confirm problems in a home. Ideally, each photo should show some kind of temperature anomaly, the hypothetical cause, and how that hypothesis was proven, or as importantly, dis-proven, and how it was covered in the report.
I’ll start with this one from a recent inspection.
These photos show with what appear to me to be “trails” in the thermal signature. Having seen this pattern in attics that had rodent droppings, my hypothesis was that there was a past or present rodent infestation.
In the attic I found the areas above had insulation packed down in “trails”, consistent with the patterns found when rodents have been moving about. I also observed a few rodent pellets. I did not excavate.
All that was enough for me to state that there was a past or present rodent infestation, but the tenant overheard me talking to the buyer about what I had found and he piped up “yeah, I hear things moving around up there, but I’ve never seen anything”. That pretty well cinched it.
Final determination was, based on thermal patterns, packed-down insulation, observed rodent feces, and statements by the tenant, that there is an active rodent infestation and a professional exterminator needs to be called in.