[Cob] dry stacking urbanite for a bench stemwall

[Terra Incognita]

Hi.

I am building a cob bench in Ithaca, NY.  I've dug a 3
ft pit and filled it with tamped gravel for drainage
and now I'm about to dry stack a bunch of urbanite
I've gotten a hold of about a foot up before starting
with the cob. 

The urbanite in question is this heavy-on-the-rocks
concrete that had been poured into molds to give the
appearance of variously shaped flattish stones. They
were a friend's patio that she came to dislike and I
took them off her hands for my bench.

  They are not totally flat. If I place one on the
sidewalk and rock it back and forth, it wiggles around
because of all the rocks in it.

My question to you, fellow cob-listers, is:  How do I
put down level courses of this stuff? Is there a trick
to it or is it as tedious as my initial thoughts on
the matter would have it (meticulously adding tiny
amounts of gravel beneath each individual piece as it
is layed down and checking it's level to the "stones"
around it)? A friend suggested that I put cob between
the courses as mortar to help level it all out and
that the drainage of my rubble trench should keep it
all safe. I'm not so sure because it snows a helluva
lot around here.  

Any advice is much appreciated. If you have been in a
similar situation, let me know and I'd love to talk to
someone on the phone about it. Thanks!



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