unreal ed cylinder issue

I mentioned this in game and I'm posting the screen shot. why are there lines along the top and bottom that are not radial or anything... confused as to what they are for and why they are like that:

That is just the way that UnrealEd renders BSP on a cyllinder with 32 sides. If the surface were flat, then it would be no problem. But since the objects are 3D, UnrealEd has to render BSP so that the starting vertexes and ending vertexes meet. There is no workaround besides converting your brush into a static mesh if you are adding it instead of subtracting it. It will not usually cause BSP cuts.

so the only way to fix the top and bottom parts of the brush is to add a sheet brush on top of the floor and bottom of ceiling?