Cob Plaster on Straw Bale walls

[Bob Bolles]

Speireag
Bill Steen was kind enough to teach us how to use cob as plaster.
The clay-sand mixture has a very high percentage of straw mixed in.
Too little straw will allow excessive cracking of the cob
We use 1/2" hardware cloth to screen the dry clay.
Bill used a wheelbarrow to mix the cob
1 1/2  - 5 gallon buckets of water in a large wheelbarrow
"sprinkle" the clay-sand mix into the water until it is even with the top
of the water
let it sit for 15 minutes or so - then mix by hand, until there are no
lumps.
Slowly add straw until you get the right mix.
The cob is applied by hand and is forcefully applied to the straw wall.
It is also forced into the cracks between the bales with a stick.
(Actually, we are using a clay-sand mix between the bales as a thin mortar
- about 1 inch works well - the bales are pressed into the mortar, and they
become "rock solid" when the clay drys)
The thickness is determined by how much of this plaster it takes to make a
flat wall.
We do apply more to the inside to create a good thermal mass - 2-3 inches.
While the cob is still wet, we place 1x2's perpendicular about 2 feet apart
- the 1x2's will stick to the wet cob.
Use cob to shim them so that they are plumb.  Cob is applied between the
vertical boards, and a screed is used to create a flat wall surface. 
Depending on how many people you have to mix and apply, you can do an
entire (small) building in a day.
The finish plaster is made with very fine fibers mixed into the clay-sand. 

We have found that we can chop up the straw with a weed eater in a barrel
If the cob drys out between applications, mist the wall (the cob, not the
straw!) lightly with a hose.
Cob is truly an amaizing material.
We are beginning to experiment with waterproofing the plaster - more on
that later!
We have used cob plaster on 9 buildings to date
In our climate, (hot and dry) the moisture has created no problems that we
are aware of.
Good luck!
Bob

You said:
To what extent have you done this?  How thick do you make the cob?  Can you
do
more than 8 inches of height per day because the cob is thinner and
partially supported by the straw bale wall?  Does this create any sort of
problem as far as introducing moisture into the straw or not permitting the
straw to breathe sufficiently?