Losing back of wall

I keep losing the back of my walls in sketchup.
They are on the right plane.
I think I used outer shell so they are all one piece (exterior walls)
They are all looking good and then something is happening where I put in the windows, start to have problems and then go inside and see the back of the wall is missing.

I am sure I am doing something to make this happen but I can’t figure it out and it’s driving me crazy.
Is there anyone who is having this happen to them and have figured out how to avoid it??
thank you!!!

Please share the SketchUp file so we can see what you are talking about.

Continuing the discussion from Losing back of wall:

Thank you Dave!
I had to keep deleting parts of the model because it wouldn’t upload (just figured out the I could purge unused) so now this model is only showing where the issue is. I hope this will show the problem and I didn’t delete too much. The way the tops and backs of exterior walls are is what keeps happeningSKETCHUP forum missing wall backs.skp (689.0 KB)
Thank so much!

Are you referring to the the face that should be surrounded by the edges I have selected?

You can restore the face if you trace an edge with the Line tool.

I’m not sure what you deleted to take that face with it but I do see that you are using layers incorrectly. In SketchUp ALL edges and faces should be created on and remain on Layer 0. Only groups and components should get other Layer tags associated with them. Keep in mind that if you explode a group or component after it has a different layer assignment, the contents of the group/component will inherit the layer so if you explode back to raw geometry, you need to correct the layer association back to Layer 0.

I didn’t realize about the exploding taking on that layer. thanks for that tip! I think because I kept deleting so much the to get the file size down to upload it, it might have messed up the layers. Yes I am referring to those layers. I do know how to correct it, but I don’t know why it keeps happening, The walls are solid and then when I go to put in a door or window and am having problems I find the face is missing and it is usually many faces that are very time consuming to try to keep repairing them. I know you can’t understand what I have done to make them disappear, I can’t even understand myself. I was just wondering if there is something I am missing that is obvious that would cause this to happen, I am still eagerly learning and keep running into this problem over and over again.

Can’t look at your model, but along with what Dave has said I’d suggest you may be misunderstanding outer shell.

I think you are right
I have to run out, will check back in later.
thank you