[Cob] Earthen Floor Question

[Amanda Peck]

My experience involving a very tiny room, is that unsealed earthen floors 
are more dusty, etc. than a well-tamped gravel base.  Mine was a finish 
single layer floor, but that would be true for an earlier layer as well.  In 
addition, does one scratch the coat of the lower layer?

Starting to work on that floor now.  Again.
...............
Bolo quoted a friend (snipped):
I have thought that perhaps it might be workable to place  an initial
layer  as a clean working
surface  at the outset --protect it with 6 mil. poly and flakeboard
during the remainder of the
building and then add on the final lift of floor material at the end.
In this fashion one would
have a stable , flat, clean surface to work on  which would certainly
make life easier than
laboring on the dusty and relatively uneven  surface of  a compacted
sub base.