Home inspectors inspect what they can see. They also check function, which sometimes is felt and smelled. For the most part, the inspectors I work with find problems that involve water penetration and leaks, structural weakness which causes sagging, old-style wiring (knob and tube), and insufficient ventilation and insulation and general aging. There are a myriad of problems that inspectors won’t notice that can use up a Sunday afternoon. One of my clients wrote me about one of them:

T.B. wrote:

We're very happy with the house, and gradually getting around to taking care of things. Recently the loose carpeting on the stairs has been getting dangerous, and a few half-hearted tacks didn't help for long. On further investigation of the worst step, I realized the little plywood strip of with 45 degree nails on the step that should have been stopping the carpet sliding forward was installed backwards, facing forward instead of back, so wasn't doing anything at all. Today we pulled the carpet up, and found every single one was backwards. The best bit is, they have little arrows on them showing which way they go. I can see getting one or two backwards out of carelessness, but getting them all wrong would take a special sort of thoughtlessness.