[Cob] sinking logs in cob?

[Kim West]

We are close to finishing the cob portion of the home we are 
building--the end is in sight--yay! Regrettably, we are running low of 
sand. We bought about 26 yards of sand last year at $250 [2 loads at 
$125 apiece], and we hate to buy another whole load for what little we 
need. The only other thing we could think of was to begin sinking things 
in the cob to take up some of the space--thereby saving the sand that 
would have been used. We did sink some urbanite that we had left over, 
but we still have a ways to go. The only other things we have to do this 
with are some iron ore rocks and some sections of wood that we scrounged 
last year. We would like to keep the rocks for other things to come 
[they aren't that easy to come by down here] so we are planning to use 
the dried cedar [Eastern Redcedar] log sections.

I know that in cordwood construction the walls are built with a space 
between the outer and inner walls--leaving a dead space or filled with 
some type of insulating material. We want to continue making the wall 
with the logs solid, though, with no space--just solid cob with logs in 
it to take up space. Has anyone here had any experience doing this with 
a solid cob wall with no air space? If so let us know--we would love to 
know how you did it and what the results were. The walls of ours that 
will be done like this are the top section of the southwest [SSW], and 
the top section of the northwest walls [NNW].

If you don't already know, we live in south central Arkansas where the 
summers are generally hot and humid [except for this year when it was 
cool and dry] and the winters are generally mild as far as winters go. 
The average first day to reach 32 degrees low temp is December 21st. ( :D)

k

PS: If you have written to us at any time within the recent past we 
probably have not returned the courtesy. We aren't being rude [we aren't 
trying to be rude], we are just hustling very [VERY!] hard to get this 
cob finished before it is too late and we have to wait another year!  We 
hope to be finished with the cobbing sometime around mid to late October 
and to write you back ASAP after that. If I forget to do so by the end 
of October write me again--I've probably lost your email.