[Cob] Slow progress on cob walls

[Barbara Roemer]

Lorraine wrote:


> We've
> found we need a wetter mix to be able to press the mix into cobs, and
> need to add a bit more straw. It's much slower as we are only going up
> about 4 or 5 inches in height per course and can only add one course per
> day as it wants to slump a bit too much otherwise.  We punch and pat the
> cobs onto the wall, not walk on it - it doesn't seem to be suitable for
> walking on without the fresh cobs being pushed off the wall.  Again,
> this probably suggests our mix isn't right.

If you use a simple plywood form, you can use a much drier mix which won't
slump.  People here using tractor cob, drier too, are using plywood forms to
go up about a foot at a time, and by the time they get to the end of a wall,
they can go up another foot or two, depending on the labor available and the
daylight hours.  You can tread on the damp wall without it spluging.  The
directions to Simon Holmes' and Rob Palacek's innovation was written up by
Jim Reiland in the latest edition of the California Straw Building
Association's newsletter.  You could make slightly curved forms to
accommodate other the straight walls, as well.