WDIR=Wood Destroying Insect Report
I recently had a question in regards to a house that was being sold and the termite inspector failed the property because of old damage and shelter or "mud tubes" on some wood joists. Now there was no activity to be seen and no live termites and the house was treated before. SO why did it fail?
In many cases a house will fail if there is shelter tubes because that is an indication that the termites may have returned after the treatment. After a treatment is done the termite technician is supposed to scrape down any visible shelter tubes. This helps to monitor the recurrence of the termite problems when the follow up or yearly inspection is done. So that is most likely why the inspector failed the property.