Any of you who have been to London and ridden on the underground, or the tube, have heard the famous term "Mind the Gap."
The term references the risk that you might fall in the gap between the train and the side of the track. We home inspectors look for gaps in other locations. For example, we want to see a gap where the wood trim ends above a flat surface such as concrete or a deck. And, up on the roof, we want to see a gap where wood trim is located close to roofing materials. In most cases, an inch to an inch and a half will do the job. The job, in this case, being to provide a gap so the wood is not resting in moisture that can wick-up into the wood and cause rot. Below would be an example of not minding the gap.