[Cob] Patio of cob?

[Clint Popetz]

I know this has been talked about before, but an hour with google and the
cob archives didn't turn up much.

I want to build a patio off the back of my house.  We don't have much
natural occurring stone (the soil is glacial till) and locally
harvested lumber (what little there is) is pricey and not of a type
that can withstand rain without treatment, so I was wondering if I
could do it with earth.  I'm imagining something like a poured adobe
floor.  Would it be possible to stabilize cob with lime, or seal it
with something natural such that if it had a small grade (say, quarter
inch per foot) and was smooth enough that water wouldn't puddle, that
it would survive with periodic re-finishing?  The edges would be
urbanite, so that the transition from patio-to-garden wouldn't erode.  

We get _hard_ downpours here in the midwest, so it would have to
survive a deluge.  I have no experience with stabilizing clay.  I have
plastered, but that's on a wall, which is only getting periodic
wind-blown rain.  

I have considered the possibility that rain-resistant floors can't be
built in a sustainable way unless you have local stone, in which case
I'll put a timber-framed roof over the patio and deal with the rain
that way.  But I'd like to sit on my patio and watch the ducks splash
in the pond with the sun warming my shoulders, and not in the shade :)

				-Clint