Re: SB: Lime versus Earth & sustain. foundations

[Barbara Roemer <barbandg@onemain.com>]

Carolyn, Matt and anyone who's interested,


I'm a novice doing lots of experimenting in a remodel with earth plasters
over sheetrock.  I follow Carolyn's line, with either clay from our toilet
pit excavation or kaolin, depending on whether I want a whiter finish or a
reddish one, adding varying amounts of the following for particular
properties:    
    € buttermilk for cohesion and hardness;
    € wheat paste for hardness and plasticity, though it affects color
somewhat (my red dirt plaster turns almost cocoa colored with wheat paste,
particularly on burnishing, and in the presence of dried cow manure; and a
thin coat of wheat paste on top of plaster is a great hardener, though I
don't think it will hold up to moisture behind a sink;
    € dried or fresh manure: cow is best (4 stomachs digest straw til it's
quite fine but not completely broken down): dried screens easily, but fresh
adds great plasticity;
    € different colored and different grit sand for strength: coarser for
rough plaster, finer for finish or aliz;
    € chopped straw for strength and beauty;
    € mica for plasticity, whiteness and some reflectivity, though that's
cut way down if you get very finely screened mica
    € pigments for coloring plaster or rubbing back into a dry plaster. (I
often use clay from our site - we have several different colors from red
through chocolate, grey, yellow, and blue)

Surfaces can be left quite rough or burnished to a satiny texture which
glows as though it's been waxed.  Sponging and then burnishing reveal the
straw and mica.  (And colored waxes are gorgeous over white micaceous
plaster, though probably can't be replastered easily.)



I don't mix cassein or
> wheat paste with the clay because it makes it go bad overnight.

I didn't think it a bad thing that my wheat paste batch smells and acts like
sourdough.  In fact, the plaster had greater plasticity after fermenting,
and the grain alcohol smell dissipates soon.  It was quite a surprise,
though, to find a batch rising like bread dough after a warm afternoon -
clearly airborne yeast had settled in the bucket.  I just stir it well,
admonish it with "down, boy!" and slap it on the wall.  The buttermilk batch
smells stronger after a couple of days of sitting, but it, too, seems
smoother with fermentation.  No hard evidence, but observation.  I think of
the poster who mentioned the Japanese idea of the materials "becoming
friendly" during fermentation when I had a problem with funky straw in a wet
poured earthen floor during the winter.

  
> Actually, when I only use clay and sand, I can tuck a little extra away and
> reuse it in the future if I need to patch.  It never goes bad.

I keep mine in dried "cookies" per Carol Crews' suggestion.  Just
reconstitute to touch up.

Of Carol, she has an article in "The Art of Natural Building," the newly
published Wanek/Smith/Kennedy book, on earth plastering and aliz.  Clear,
helpful, thorough, but you MUST make samples with your own clay and try out
the plaster under different light at varied times of day.

Of "Natural Building," Rob Tom's article on rubble trench foundations has
been invaluable to us.  Clear drawing, excellent method, well explained.

Put the book on your wish list - every article is written by someone with
plenty of experience, clearly illustrated, and articulately written, and the
book is truly encyclopedic in its coverage of natural building topics.

Barbara

 


-------------------------------------------------------------------------
To unsubscribe from the list, send a message to:
   <strawbale-unsubscribe@crest.org>

or for the digest to:
   <strawbale-digest-unsubscribe@crest.org>

Please send any list administration questions to
strawbale-owner@crest.org