Cob:

[Darel Henman]

Just some comments inline below:

Grei Raven Shadow Walker wrote:
> ........ snipped
> You either a waterproof/resistant
> insulation material such as light clay, wool, 

These two are not waterproof or water resistant.

> or any one of the many foam insulations available. wool is
> one of the rare insulation materials that doesn't lose
> it's r-value when wet, 

It does lose R-value when wet or you can look at it as the total R-value
of the water content and the Wool content.  The water content replacing
the air films which is the real insulator and water is a far better
conductor of heat/cold than air.   Wear a wet wool shirt out in the cold
and compare it to a dry wool shirt.  You'd see the R-value is different.

>cotton unfortunately does.
At the moment I can't think of any material that's r-value doesn't
change when saturated or wet.  

The key is to provide a breathable, yet water/rain drop proof rendering
over the insulation material.

Darel