Lab Rodent Exclusion Project
not related to these guys in Pennsylvania) are now translating into about $6K out of pocket and a couple months of hard work. The otherwise excellent 3000 square-foot "monitor style" building is only 6 years old.
The photo shows one of the corners of the building, with its spacious and wide-open cover removed. The metal exterior skin is screwed to the 2x6 girts, which are in turn fastened to the vertical corner poles... resulting in a long floor-to-ceiling gaposis that's big enough to pass rats. The related problem is a gap every 9 inches around the building where the metal overlays the baseboard, allowing mice to come and go freely and tunnel through wall-insulation to their prime nesting grounds up in the ceiling batts. In the photo, you can see where I have already started closing this off with metal flashing from Home Depot. Finally, just to achieve maximum species diversity, there are similar gaps where walls meet roof, and at least in one area we also found evidence of bat nesting.
The sad part of all this is that $60 worth of said flashing, some goo, and a bunch of random 2x4 scrap nailed between girts at the corners could have completely prevented this problem... which has involved complete removal and disposal of the building insulation, tedious retrofit of rodent-exclusion steps that would have been trivial during construction, and re-insulation. There is no choice in the matter; the building started to stink so badly over the past couple of years that working out there was becoming intolerable.
Needless to say, I am more than a little disappointed in the contractor; they should have been aware of this problem. In retrospect, I probably should have noticed it and brought it to their attention, but what does a techno-geek know about erecting pole buildings? Ah well, lesson learned. (And if you're looking for a contractor, no, I don't have any recommendations...)