Cob: Introduction

[D.J. Henman]

Alberto,
   would you clear up some puzzles  in  your post, included below.

All soil has some sand in it as well as some silt.   Have your done any 
simply jar tests yet?
You mention pouring water all day long.

Alberto Duran wrote:

> Greetings Cobbers!
> I've been on this list for about a month and thought I should jump in
> and introduce myself. My name is Alberto and I live in Banquete, Texas.
> This is a small farm community about 35 miles west of Corpus Christi.
> Out here the soil is a heavy black clay referred to as Victorian clay.
> There is NO sand in this stuff! ......snipped some.....

> Speaking of which- around here there has recently been drought
> conditions which can cause the ground to crack and split.

This is normal and happens when soil dries, more so for more clayey soils..

> Sometimes,
> for example, when I water my plants (I grow gourds) the ground will just
> collapse and the water just keeps going and going and ( someone earlier
> brought up the silly cartoon idea of this water leaking down to
> China...ya never know..)

Yes we do know that it won't go to China.
But, the puzzling thing here Alberto is that a pure clay soil would not 
collapse and keep accepting more and more water as the clay would expand 
and clay is a good water proofer that would keep water going deeper.   
What you described is more like what would happen in a deep sandy area, 
where the water could flow through.

> it never will fill up since its so deep!

What's so deep?   There must be a lot of sand under a foot clay layer 
for example.

>   Anyway,
> this is obviously a concern since I would not want something that I build
> to just slip away.

This is a problem with sand soils.

>   And-I really hate the idea of having to pour a concrete slab for
> a foundation.

What do you plan on doing for a foundation?
A rammed stabilized soil foundation might be a good way to go.

> It may be that I'll have to eventually build using a method other
> than cob- straw bale  for instance.

This through me off.  You were talking about cob and strawbale.  Were 
you going to use them both in a hybrid structure?

> I've considered perhaps using the rubble
> trench method for a foundation but... I'm just not sure. I've had a 
> little past
> experience working with clay (the kind that you fire) so cob really 
> has the
> most appeal to me for a building material!


What's your water table level there?

>            Alberto Duran

Darel