Cob: RE: RE: Insulation for cob

[Avalon Bruce]

WELL, what about shopping (grocery store) bags stuffed with styrofoam
pellets for ceiling/attic insulation?  wouldn't THAT work -- god knows
there's a TON of that stuff being thrown away daily!  av

and as for WHY bag it up, because it's easier to CONTAIN , i.e. handle,
that's why !!!



----- Original Message -----
From: The Van Wey Family <vanwey6 at bitterroot.net>
To: Michael Saunby <mike at Chook.Demon.Co.UK>
Cc: 'Kelly, Sean' <SKelly at PinpointTech.com>; <coblist at deatech.com>
Sent: Thursday, July 08, 1999 3:28 PM
Subject: Re: Cob: RE: RE: Insulation for cob


> Michael,
>
> I terribly afraid I need to disagree with you an a point. The "just
chucking
> in" of things... When I suggested the use of the styrofoam beads or other
> matter to be imbedded in the cob walls to help with insulative values of
the
> walls, it was not "alchemy" by any means. As you undoubtedly know,
styrofoam is
> basically suspended air if you will. As such, it might provide the
"bubbles"
> you spoke of, which was my point from the beginning of the thread. I do
not
> know much about cob construction, and even if I had merely just been
"chucking"
> things in there to try, wo be unto him that prevents the wonderous mind to
dare
> to create and explore the possiblities of trying new and untried things.
If
> more had that attitude, we would probably still be in the dark, because
surely
> edison would not have figured that tungsten was the key to the lightbulb.
> Instead it took him over 900 attempts with different matter (including
> horsehair!) to finally figure it out.
>
> Sorry - ---> Rant is now complete! Please take no offense!
>
> Shane Van Wey
>
> Michael Saunby wrote:
>
> > On 08 July 1999 16:04, Kelly, Sean [SMTP:SKelly at PinpointTech.com] wrote:
> >
> > > post, cob is just clay, sand, straw and water.  The strength comes
once
> > > it is dry.  The clay acts as the mortar or glue, the sand (needs to be
> > > angular, not rounded beach sand) acts kinda like interlocking bricks,
> >
> > I know the new cob builders use rather different mixes but traditional
cob
> > (once it's gone off) is earth, straw, and some moisture.  The earth is
of
> > course a mixture of stones (about 1 inch or less) down to sand (though
not
> > much where I am) and clay.  It's also go a lot of fine gaps in it, since
if
> > you add water the mass increases considerably but not the volume (a
simple
> > test of such things). The straw acts not just to hold it together but
also
> > to hold it apart, reducing the external shrinkage.  Adding lime also
> > reduces shrinkage and probably has a reasonable history so your wall
might
> > even last (if that matters).
> >
> > In the end it's like the stuff about newspapers earlier this week, most
> > solids are poor insulators, it is usually the air trapped inside or
between
> > layers of the material that keeps heat in or out. Rather than adding
funny
> > stuff all that's really needed if you want good insulation is lots of
fine
> > bubbles, which would also reduce the volume of materials needed.  How
you
> > do that I don't know.  Even so, it's always much better to start with
basic
> > physics, chemistry and engineering than alchemy.  Just chucking
something
> > in because it has a certain property is a waste of money, you usually
find
> > that it's the method of use that gives it the property not some magic
> > contained in the material, even newspapers or earth :-(
> >
> > Michael Saunby
> >
>
>
>
>