SB: Cob Plaster on Straw Bale walls

[Thomas P. Morrissey]

What purpose are you trying to achieve in applying 
cob as a plaster to straw bale?  Sorry if I missed
that in the thread of discussion.  

I've seen cob used as a way to smooth out the 
surface of a SB wall by shoving cob into the 
joints/cracks in the SB wall.  Not only does
it smooth out the surface of the wall prior
to plastering, but it also makes the wall a
lot more stable / sturdy.  You then have to
apply less scratch coat to get a smoother
wall.  

If you are after additional thermal mass (on the
inside of course) by putting a "cob plaster" on
the interior I guess I'd suggest cob internal 
walls or a cob bench or two.  If you have an 
earthen floor along with "normal" earthen plasters
and some cob walls / benches I'd suspect that 
you'd have plenty of thermal mass for most
locales.

Maybe this is just semantics, but "cob" and many
earthen plasters share the same ingredients (clay,
sand and straw), so in fact many plasters are "cob".
Most folks think of "cob" as the wall material composed
of relatively course particles of clay, sand and straw.
Earthen plasters (from scratch to finish) can be made
with the same ingredients in successively finer particles
and in slightly different proportions.  

-- Tom Morrissey,  thomcelt at juno.com
USPS: 5569 N. County Rd 29, Loveland, CO 80538  Phone: 970/679-4265

On Sun, 29 Jun 1997 12:14:30 -0400 Speireag
<speireag at linguist.dartmouth.edu> writes:
>>We are doing lots of SB here in Southern Cal (finally),
>>and both in Mexico - have used cob plasters quite a lot but just 
>beginning
>>our first cob building.
>
>Bob -
>
>    It occured to me a few weeks ago that you might be able to use cob 
>as
>plaster on a straw bale structure, and your comment reminded me of it. 
> 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?
>
>    Since this speaks directly to straw bale construction, I'm also 
>sending
>it to the Straw Bale list.  Any balers have experience or comments?
>
>-Speireag.
>
>0=3D=3D=3D=3D=3D(---------------------
>Speireag, aka Joshua Macdonald Alden (speireag at linguist.dartmouth.edu)
>Ma 's e ur toigh le, sgr=ECobh thugam anns a' Gh=E0idhlig
> agus tapadh leat airson mo Gh=E0idhlig a cheartachadh.
>
>
>