Restoring volume closure, what causes plane to be lost?

On my model I traced an imported 2d drawing to define my walls. The area was continuous for all the walls, allowing me a push pull tool to stretch to wall height. Some how, and I do not know why, the top plane of the wall was lost, allowing a view inside the volume of the walls. Is there any smart way, other than retracing all the walls again to cap the wall where the lines are already defined? I have noticed that I can not get the push pull tool to cut a void in the wall when there is no cap to wall.

I appreciate your help.


You should be able to fix all of the top of the wall by drawing only a single line.

Just a guess–did you draw the lines for the walls on a large rectangle?

Assuming the lines to be coplanar, you should be able to trace one edge with the line tool and get the face to fill. In some rare cases, I’ve found you need to draw a line between outside edge and inside to get the face to fill. After the face is formed in that situation, you should be able to erase that line.

That worked, thanks. I knew it had to be simpler than retracing. The penetration tool also worked.