Man, it's been a while since I posted. I have a scene I'm working on that has a street/alley. I start with a polygon plane (40 x 30) with 10 x 10 subdivisions. I insert edges to create a curb on either side of the street. My goal is to lower the street portion by selecting the faces of the street leaving the curb and sidewalk elevated slightly.
Problem: I select the faces and extrude. The street section drops but leaves walls where the lines separating the 10 x 10 subdivisions were. Kinda like a bunch of square swimming pools. I've seen this done and it works. Can anyone tell what I'm doing wrong from that description?