Cob submissions

[Shannon C. Dealy]

On Wed, 12 May 1999, Don & Jannet Ewing wrote:

> Is this the address for submissions to the coblist ?

Yes.

> I am a missionary in Honduras working with danificados, people who lost
> everything in the hurricane. We are beginning to build houses out of
> adobe using a mechanical shaped brick press. Our house uses prefab metal
> roofing erected by gringos and walls built of local dirt by the people
> who will receive the houses.
> 
> Does this style of adobe satisfy requirements to be called cob ?  I
> didn't think so..

Not in my book, cob has a fairly high fiber content (usually straw), and
generally when building with cob, you build free form and without
using/making bricks (this is a big advantage if you don't have a press,
or if the press can't keep up with the demand).  Normally cob is applied
in layers to create a wall that is a single monolithic piece.

> How do tropical insects like the inclusion of natural materials into
> brick making ?

Don't know, but I wouldn't expect it to be much of a problem, since straw
has very little food value, and the critters would have to go through a
lot of dirt just to get the straw (cob is around 10% straw which means the
other 90% is sand/clay).

> We don't currently use anything but a clay based dirt, we don't need
> tensile strength because the bricks are made on site and inside a wall
> within a couple weeks of being manufactured.
[snip]

The point of the tensile strength is to hold the wall together once it has
been built.  During settling or in an earthquake or other natural 
disaster, an adobe brick wall will tend to fracture along the joints
between the bricks.  Cob on the other hand has no joints and is reinforced
by the fiber, so it should be far less likely to come apart.


Shannon C. Dealy      |                    DeaTech Research Inc.
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