[Cob] Curious about the clay

[Lance Collins]

Bob wrote:
>The word "clay" is used repeatedly but really where exactly is all 
>this clay coming from?  I have no idea where I'm supposed to get all 
>this clay.  For me, it would be easier just to buy clay from a 
>ceramics shop but I don't even know if that would work.  I live in 
>an urban area and it's not like we can just go out and dig up clay 
>at a local quarry.

Several years ago I had a visit from the famous Mr Dealy who thought 
it unusual that my soil was suitable for cob without any 
modification.    If you look up clay on wikipedia you will find that 
clay is a mixture of many different substances in widely varying 
proportions.

If you want to build with earth the first step is to study what you 
have available locally and work out what to do with what you have to 
get a satisfactory result.  And local can be very local 
indeed.   About ten metres from the material Shannon thought was OK 
is a patch of most unsuitable soil.

Earth building is a practical thing.  No amount of book learning will 
be of much use until you have gotten your hands dirty.

Lance