Edit: This is fixed now!
Hey sorry for the late reply.
That was intended to be layed upon several layers of floors and there should be another tike behind it.
So 1st floor would be on a lower layer, then second floor , etc...
But frankly, after revamping the walls in the upcoming update I've looked into this, and it makes no sense.
In the next update (saturday) this will be fixed already.
Thank you for the heads up!