[Cob] foundation, concrete

[Amanda Peck]

If this is still available take a look at this--it didn't turn up when I 
just tried to find it--a short booklet on design of earthen buildings for 
seismic areas by Gernot Minke and his students--and the price is right.   I 
emailed them to ask.

http://www2.gtz.de/Basin/publications/books/ManualMinke.pdf

I really don't know enough about the subject to speculate on a grade 
beam--with or without reinforcing bar.  Not much is going to help in a big 
earthquake.  Various methods will do more or less good for the smaller ones. 
  Since the big fault is quite a ways away from me, we tend not to think 
about it in design situations.

There is a technique called "light clay"  in which straw--not chaff--is 
tossed with clay slip to form walls of nearly any width you want--packed 
firmly into forms that are then moved up.  More straw, less (none!) sand 
than cob.  Horizontal reinforcing bar--almost any kind--bamboo is good, weed 
tree saplings--sound like a use for them, metal--put in before you move the 
forms.  once the wall is up, then it gets to dry for a while.  And then it 
gets plastered, usually.   You might or might not want to use it for 
external walls, or if you want the lovely wavy cob walls of the cob revival. 
   But internal walls--at the same kind of thickness as the wattle and daub 
might be wonderful.

Predrag wrote (snipped)

Regarding foundations, maybe to think about concrete grade beam to protect
the house from earthquakes? And than stone blocs on it, or cob directly?


The idea about cob with the wattle and daub technique you have mentioned was
very interesting to me. Traditional building in Serbia use this technique,
but it is not pure cob, but chaff and clay. Of course, sand is already a
component of clay. It is maybe a good insulation but not as solid as cob is.
Walls in these houses are not too thick, often only about 8 in. or sometimes
thiner. It is maybe it needed much of labor work. The houses are very
pleasant to live in, excellent in summer, but not so warm in the winter, I
think there is a need for more thermal masses.
And also, our tradition use wooden pillars but cob building doesn't. Or we
can combine that?