[Cob] purpose of straw in cob

[Ocean Liff-Anderson]

this question reveals much that needs to be learned...

how can you be "ready to cob" if you don't know why straw is included  
in the mix???  just where have you learned about cob, and from whom  
did you learn it?

in order to mix and build with cob, you need to know several things -  
quality of clay, the right kind of sand, the best quality straw, and  
the right mix of all three, along with water to mix them into cob.  i  
can't believe that there isn't any straw in the state of georgia.   
what do farmers do for their animal bedding?

don't build with cob until you take a workshop, from someone skilled  
in cob building, who can then explain all you need to know - the  
proper way to make a good cob mix, a good foundation, a good roof.   
if you are planning to build a structure which will be inhabited, you  
must do so safely, or face the possibility of a catastrophic failure!

sorry to be the harbinger of doom and gloom,
ocean

On Jul 12, 2007, at 10:20 AM, Damon Howell wrote:

> What is the purpose of straw in a cob mix? Nobody seems to "really
> know" what the role of straw is anyway. Is it there to hold the cob
> together while the wall is still wet (like a free form), or to keep
> the wall from crumbling incase it cracks later (like reenforcement),
> or to allow air/water to move through the wall (because straw is
> hollow)? The problem is that nobody knows the reason they used straw
> because they didn't leave behind notes on how and why they built that
> way, and it's been a while since they lived here. What do they do in
> Africa? Do they use straw "in" the cob? Can any other plants be used
> as tensile such as long grasses? I'm almost ready to start cobbing
> but straw is just unavailable in GA right now, and what straw there
> is has a very high price on it. I'm not willing to pay three times
> the price for it if there's a substitution. I would love to just go
> out in the field and get some tall grass if it would suffice. It's a
> heck of a lot cheaper!
>
> Chow,
> Damon Howell
> North Georgia, US
>
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