This is an exploratory question. We are playing with the idea of tracking our Base and Surface materials as stacked records to better represent how they are in real life.
Currently, we have a Base Event that tracks Base Type and Thickness. Then we have a Surface Event that has columns for Exposed Surface, Primary Surface (the predominant material), Original Surface, and then total thickness. So you have one Base Event record that spans the segment and one Surface Event record that spans the segment. This gets us most of the information we need, but you don't have the full picture of all the potential layers of material between the base and the exposed surface.