EDIT: Nevermind, I figured it out, it's considered a "Floor". Sorry

Wouldn't it be great to have Half walls?

I was just curious actually, this second floor isn't able to have anything placed on it? This is odd. Any way of having a second floor to your castle and be able to place things on it?

http://imgur.com/a/GkF1u
Could you clarify what you mean?

I placed two walls on top of one another and then tried to place the Ceiling for the second floor, but it auto attaches to the top most wall instead of able to place it half way up. But, if I only have 1 high wall, and then place a ceiling and then place another wall, it works. The "Floor" does not act as a foundation. I made another post on a error while placing Castle Walls on Castle Fence Foundations.

Thank you for the clarification! I have noticed a few times where, if something is already snapped to an wall, it causes other things trying to snap to it to ignore the original piece. Sometimes, though, you need to look down to the point that you can barely see the piece snapping where you want before it lets go of the 'open' snap point above. I will also double check in the ADK that something didn't go awry with the values on looking for an open structure snap point.

Currently, the Ark default pieces working the way I want is hindered by the snap system not working correctly with exclusion types. What you're seeing is the Ark regular wall trying to snap to the foundation below, using the ceiling as temporary ground. Its how my castle walls snap to ceilings without walls needing to be below. I will play around with making the ceilings count as foundations and see if that helps. I will need to do some testing to make sure it doesn't break anything else but will let you know what I find.