Cob Clay, Fibers, & FC

[avalonb]

well, i COULD attend a $450.00 - $1200.00 cob workshop, IF i had someone to keep my handicapped child, water the fall garden, feed all the animals, milk the goats and throw in a few more hundred for air fare --

OR i could buy the $22.00 cob building book,

OR, since i don't have the 22 bucks right now either, ask this list

can anyone provide some starting pointers on making 'cob'?

I have 4 acres of 'clayey' (slippery when wet) soil/dirt, plenty of grass hay and am 6 miles from west texas sandhills (ACRES of sand)

WHAT IS A GOOD STARTING RECIPE for making these here mud pies?

3 parts soil, l part sand and a handful of dried plant matter or WHAT?

last, but less important, how is cob really different from adobe, other than not needing the forms and drying time for the adobe bricks?

thanks for input. avalon

----------
> Hi Ron,
>
> The best way of finding out what clay works best in your situation is to make
> test bricks of varying proportions of clay sand & earth that are available at
> your site. For each brick, record its recipe and when dry compare its
> properties, such as strength, weight, cracking, does it crumble, easy to break
> or is it rock hard. Some clays have quite high silt content making them less
> suitable. Stickiness is a good indicator as the clay is basically used as a
> glue.
>
> Fiber cement would probably work ok for non-load bearing interior walls. But
> you might also want to consider other alternatives such as clay straw which is
> also cheep and doesn't need custom mixing machines, or thin burlap bags filled
> with stabilized earth and wood chips, or other combinations. You could also
> use other natural recipes such as roman cement which has held up the Roman
> aqueducts for the past 2000 years. I have forgotten its recipe but it is light
> and strong. I would look towards using available natural materials that are
> close at hand (on your property) for the best return.
>
> What is pine straw? Is it the smooth pine needles you are referring too?
>
> Regards,
> Will
>
>
>
>  -----Original Message-----
> From:	coblist [SMTP:coblist at deatech.com]
> Sent:	Thursday, October 15, 1998 8:49 AM
> To:	coblist; WFIRSTBR
> Subject:	Cob Clay, Fibers, & FC
>
> Greetings All,
>
> So, for my first question/contribution to the list, I have a concern about
> clay.  In this area, we have two types of clay:  an orangey-reddish clay that
> is most often found in the upper levels of soil, and a sticky grey clay (it's
> called gumbo around here) that is often found a bit deeper.  While I suspect
> clay is clay, instinct tells me that the gumbo would be a better choice to use
> for cob.  From the broad range of experience out there, I'm wondering if you
> all feel there is any benefit to using one or the other?
>
> Second, I'm curious about what plant fibers work well in cob.  I've read the
> archives (yes, ALL of them!) and while I've read of folks using plant material
> other than straw, I'm curious if anyone has tried pine straw?  With all the
> pines in South Carolina, we have an abundance of the stuff.
>
> Finally, regarding fibrous cement: if I understand correctly, one of the main
> drawbacks to the material is water absorbency, making it unsuitable for
> exterior walls and such in wetter climates.  However, what about using it for
> lightweight, non-structural interior walls?
>
> Metta to all,
>
> Ron Cameron
>