Cob: Cob Walls and Buttresses

[Kim West]

Some of you may remember that I decided to build a rectilinear home and dug
the foundation accordingly. I had planned to put in buttresses for support
since the walls were going to be straight. Well, I have learned much from
this cob building experience and one of them is to not be inflexible. Since
starting the walls I had a change of heart and instead of making the walls
so straight I decided to let them undulate. If you look at them from above
the sides are not going in symmetrically wavy patterns but are following the
outlines of the stones jutting out from the foundation under them. The
inside and outside faces may make perfectly parallel [though wavy] lines or
they may move towards or away from each other, making the walls varying
thickness in places. Some sections are straight but not for long distances.
So far it looks very pleasing to the eye although I realize that it may make
the lime plaster/render job more of a task later. I am wondering if this
will be far enough away from straight lines that buttresses will not be
required. Anyone have any idea?

As an update to those who have been staying tuned, our building progress in
August was about half of what we had expected it to be. August is supposed
to be our hottest, driest month here but you could have fooled me this year.
It, like the other months this year, was very wet and we had thunderstorms
almost daily. Working evenings was out of the question due to them and I had
to spring for $30 light to use outside after dark just so that we would not
get so far behind that it would be impossible to finish before cold weather.
I can only hope that we do not have an early and cold winter. So far I am
getting back aches from pressing and poking the layers of cob together, but
the legs and the rest of the bod are holding up well with no probs at all.
I've read that you can walk the cob down but this stuff is so slippery I
can't see it myself. Just wish we had a decent place here so that we could
invite folks to come here to help. Some help would be great! haha.

Another thing slowing us down is that the clay we are using now is very good
and sticky and so close to pure it could be called pure. It is hard to get
it to dissolve in the water whether wet or dry when you try--it would much
rather just stick to your feet in thick globs when wet and have you deposit
it somewhere other than where you want it, or fool you into thinking it is a
rock when dry, making you go get a screwdriver or hammer to verify what the
heck it is. This is good since it will make for better cob, but bad in that
it takes so much longer to get the clay ready for the sand. Lots of hand
action is necessary to prepare it and keep it where you want it.

Another thing I maybe should ask is whether anyone here has any experience
with acrylic. I found some acrylic plates for 50 cents apiece and bought
some to use as windows. They are either a light blue or clear and they have
a raised dot pattern on the rim that looks really nice when light shines
through them. I figured at 50 cents a pop you couldn't beat them unless you
found glass for free. I did an online search and what I found said that
acrylic has a melting point of between something like 106 and 200 something.
I hope that is right. We left some "glasses" of the same material outside
all summer and they seemed to suffer no damage from the semi-tropical heat
down here.