Cob: Re: straw wattle

[Shannon C. Dealy]

On Sat, 26 Jul 2003, andrea arnold wrote:

[snip]
> worked well, though it was surprising to me how much
> clay we needed.  I always here how cob is more sand
> than clay.  But with everything else we did - clay
> slip to dunk bales in, clay slip for the light
> straw/clay, clay for the earthen floor and plasters,
> clay for the cob - I think we used more clay than
> anything else (sand, straw, etc).
[snip]

You need to keep in mind that a "clay soil" may still have alot of sand
and/or silt in it, so it's possible (I don't remember what the soil
composition is like where Michael is building) that you weren't using
nearly as much clay as you think.  To get a good cob mix with the (high
clay) soil here requires about one part sand for every part soil (and even
more sand for a good floor or plaster mix), but the soil is actually only
about 35% clay, so even when using it as a slip, the clay is still very
much the minority of the mix.


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