Can't Edit Brick Walkway

In the picture I added, there is a visual of a brick walkway outside of the Parkshore house. I can't seem to get rid of it, no matter what I try. It is not a sidewalk or outside, I can't paint over it with the terrain tool, but I can change it with the indoor floor tool. So I tried using the "remove floor" tool, but it doesn't register it as a floor. I built a room around it and clicked remove floor, but the floor stayed underneath the new floor. I'd really like to get rid of it if anyone has any ideas, I'd appreciate it.