[Cob] shelves

[Marlin Nissen]

There could be an engineering calculation about spans
and weight (force) in the middle of the span except
cob varies so much.

It seems to me that you're asking about the shear
strength of a "flat" cob shelf? Instead, if you were
creating a bridge shape, which is an arch and
distributes the weight to the outter walls.
 (see attached drawing)

Otherwise you're exposing the cob to straight DOWN
force which could expose a crack, likely near the
center of the span. I've seen (in pix) sticks or
bamboo shelf structures (horiz. girders) with cob over
them that strengthens the span.....but why not try the
arch? It doesn't have to be a full "Roman arch" even
though that's the strongest but cuts away a lot of the
space of the shelf below.

Cob with a good amount of long straw would (I'm
guessing) be good for the strength of the shelf span.

A little arch will do ya,,,,

Marlin

p.s. great way to experiment with only books falling
down.....




--- Copper Harding <copperharding at yahoo.com> wrote:

> Ok.  So does anyone have any thoughts on the maximum
> shelf length, width, extension that one could make
> out
> of cob?  Does anyone have any approximate formulas
> for
> extension and width versus thickness of the actual
> shelf?  Has anyone managed to overload their shelf
> with books and have it fall on their head?
> 
> Thanks,
> 
> Copper
> 
> __________________________________________________
> Do You Yahoo!?
> Tired of spam?  Yahoo! Mail has the best spam
> protection around 
> http://mail.yahoo.com 
> 
> _______________________________________________
> Coblist mailing list
> Coblist at deatech.com
> http://www.deatech.com/mailman/listinfo/coblist
> 

__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com