Cob cob / ceramics

[David DeFauw]

It seems this message was shredded in cyberspace so I'm sending it again. 
Sorry if its a duplicate.
Dear Adam at University of Oregon and cobbers,
	An awesome research project would be on the thermal properties of cob in
maritime climates like Oregon.  Any permitted cob building will need to
pass the energy code.  Cob houses are beautiful but it is not clear how
energy efficient they are.  Many say they are comfortable.  Bring on the
scientific proof so everyone will believe it.  That would be accomplishing
something important.

Also in wonderful wet (Portland) Oregon,

David DeFauw.

----------
> From: Adam Weiss <aaweiss at darkwing.uoregon.edu>
> To: coblist at deatech.com
> Subject: Re: Cob cob / ceramics
> Date: Tuesday, October 28, 1997 3:29 PM
> 
> >goshawk at gnat.net wrote:
> >>
> >> > lars wrote:
> >> >        this is kind of an aside - maybe pat newberry might know
best:
> >>does
> >> > anybody know why it is inappropriate to mix straw with clay if one
is
> >>making
> >> > bricks for a fired structure 'a la nader khalili'?
> >>
> >> Remember Superadobe and Nader's fired sturctures are two different
> >> animals. You can use straw in superadobe (I often do at the ends of
> >> bags) but I've never seen any pottery or fired bricks with straw so
> >> my guess is that the straw would disintergrate and the weakend
> >> structure would still not gain that much in insulation value from the
> >> air pockets.
> >
> >	i understand the difference between the two. sorry if i caused any
> >confusion, though.
> >
> >	pat: why do you use cob at the ends of the superadobe bags?
> >
> >	and back to theory: yes, N. khalili _does_ specifically state that one
> >should not mix straw with bricks that are going to be fired, but he
never
> >states
> >why. i'd just like to know the reason. he does talk about using a wood
member
> >embedded in the wall which would then completely burn out when the
> >structure is
> >fired, leaving a conduit for electrical lines or plumbing. this also
helps
> >assure
> >that the heat reaches deep into the wall and evens out the firing
process.
> >	i was imagining using the same technique, but on a smaller scale.
> >where
> >the pieces of straw burn away leaving myriads of air pockets. if one
fired
> >a cob
> >structure made out of the right proportions (whatever that might be) of
> >clay and
> >straw, then maybe one would get a lightweight, water-proof, semi-porous
(high
> >insulation value) material - kind of like making your own pumice on
site. it
> >might also help ensure even firing of the wall, allowing the heat to
more
> >easily
> >reach deep into the thick walls.
> >
> >	waddya all think? fired cob? hmm.... or maybe fired
> >wattle-and-daub, or
> >firing bricks made from woodchips and earth. anybody out there ever
fired
> >a cob
> >structure? i think the ratio of earth to straw/woodchips might be
critical
> >(if
> >the idea had any chance of working anyway, which i'm not convinced it
would).
> >
> >just some crazy thoughts.
> >
> >lars fields
> 
> Lars- these ideas sound pretty interesting and could use some good old
> fashioned experiementation.  I am a graduate student of architecture at
the
> University of Oregon and we are looking for some interesting hands on
> experiments like this.  Do you think you'd like to build one, burn it,
and
> see what happens?  Perhaps with some sponsorship from the university?
> anyhow, I thought it might be fun and informative.
> 
> -Adam Weiss
> IUniversity of Oregon
> 
>