Cob: Re: Cob plaster on a conventional wall!

[Darel Henman]

Experts install a cloth mesh or strew straws across wood to be mud
plastered over.  Then mud over it once.
Then the whole wall again.  This is to 1.) prevent cracking from the
joining above/below top or sides of the wood to the mud and also 2.) to
prevent the wood from bleeding and affecting the color of the final coat
of plaster.

Darel

dtebb wrote:
> 
> Thanks for the info. What is plaster lath (extruded metal)? Was your wall's
> sheathing the same as the old wood lath used on old houses? Did you try
> plastering directly on the wood sheathing? What color did your wall dry to?
> Sounds like you didn't use any color pigment.
> 
> By the way do you have Kiko's address. I worked on a project with her once,
> but lost her contact #. I would like to ask her how she did the interior of
> her conventional house. Yes Kiko does amazing work and knows her plasters
> well. The oven you are talking about, you don't mean the bee hive house do
> you? That is a beautiful structure.
> 
> Ian
> 
> >Hey, all!
> >
> >Checking in from Corvallis...
> >
> >Regarding plastering conventional housing, for the restaurant we are doing
> >one wall with a cob plaster bas relief mural, and we just nailed up plaster
> >lath (extruded metal) over the wall's sheathing and then trowelled on a
> >simple plaster of red clay, sand and chopped straw.  The plaster on the stud
> >wall seems to be holding very well.
> >
> >We sieved pureed clay through a 1/4 inch mesh, and chopped the straw with a
> >rented chipper/shredder.  The shredder turned one 100 pound bale into about
> >250 gallons of chopped straw (5 huge bags).  We're also using the same
> >plaster on the garden wall, about 140 feet long.  We mix the plaster in
> >large quantities with an electric cement mixer, a ratio of 1 bucket pureed
> >clay, four buckets concrete sand, 1 bucket chopped straw.  The metal lath
> >was purchased from the local cement products store, but maybe chicken wire
> >would work as well.
> >
> >We'll be posting a website for the restaurant soon, with lots of pictures.
> >But for now, I've got to get back to the project.  Hey, Kiko has built the
> >biggest cob oven ever!  Wait till you see this thing!
> >
> >Peace and Blessings,
> >Ocean
> >
> >
> >> From: dtebb <dtebb at alternatives.com>
> >> Reply-To: dtebb <dtebb at alternatives.com>
> >> Date: Wed, 2 Jan 2002 01:21:25 -0800
> >> To: coblist at deatech.com
> >> Subject: Cob: earth plasters in conventional housing
> >>
> >> Friends of mine just purchased and gutted an old house, soon to be
> >> re-drywalled, painted, etc. We plan to do some experimenting with earthen
> >> plasters at least in one room as a demonstration project here in Vancouver.
> >> Some of the old drywall will be left in place and in other rooms, the
> >> drywall or old plaster was striped to the wood lathe.
> >>
> >> We plan to use a traditional interior earth plaster either over the drywall
> >> or lathe. The plaster that I have worked with is kaolin clay, silica sand,
> >> straw fiber, mica, pigments and white glue. I would also like to experiment
> >> with something other than white glue.
> >>
> >> We will begin with some test boards including chicken wire over drywall and
> >> lathe, directly on drywall and lathe without chicken wire and a rough coat
> >> (perhaps white glue and sand) on the drywall in place of chicken wire.
> >>
> >> I have only seen one house, Kaki's in Moab, Utah in which the interior of a
> >> conventional house was completly redone with natural plasters and paints.
> >> It looked beautiful.
> >>
> >> Does anybody have experience doing this? What did you do? how did it work?
> >> Your responses are appreciated.
> >>
> >> Ian
> >> Down to Earth Building Bee
> >>
> >>
> >>