It appears that I cannot put down any floors underneath the 3 foundation pieces.  (pics)  If there's no problem with it, you can see by my beautiful design work [grin], that it would be a nice addition.

What's weird is pic #2.  Where it shows that you 'can' put a floor on one of them, if they don't have one above them.

Anyhow.

#1

#2

#3

..and here's one with nothing above it, yet.

I ran into this bug while live streaming xD.

I will try to fix it before the next update, thank you!

Cheers!