@thomthom said:

Can you post that sample model?

I've attached it.

floorplan.skp

I selected all the lines in the floorplan and selected the face (which included the outside area...because it will not allow me to select just the floorplan face)
and I right clicked and selected "Intersect Faces | With Selection"....

it did not seem to do anything. When I select the floorplan face, it still selects the outside area as well.

Are these leaks common?

here's a screenshot.

The floorplan on the left cannot be selected. It selects the floorplan and the outside area.
The rectangle on the left is normal, it can be selected.

Its like there is a hole in the floorplan, even though, i just created it and there is not.

I have students who create floorplans in google sketchup, nothing super accurate, just a basic layout, and there are many instances where the entire floorplan looks fine, I don't see any holes in the floor plan, but when you try and select the floorplan, it leaks out into the large rectangle they are building the floorplan on.

As far as I can tell, the entire shape of the floorplan is connected, there are no holes.
Why does this happen?