[Cob] Cob in Ohio

[Shannon C. Dealy]

On Tue, 2 May 2006, Rob Lewis wrote:

> I have been consulting with a green architect who has advised me not to
> build with cob. This is because the area where I live, northern
> Kentucky/SW Ohio, is, according to him, unsuitable for cob. His main
> concern is winter temps and r-factor/insulation issues. Is there any way
> to salvage my dream of building cob on my property?

A few methods have been tried which might be of interest.  A number of 
cob structures have been built in cold climates (some much colder than 
yours):


    - Build a cob straw bale hybrid, strawbale walls where the building
      doesn't receive direct sunlight, and use cob where it does (to store
      the solar heat), possibly with a glass wall outside of the exposed
      cob to help it capture and store heat.  Putting holes in the top
      and bottom of the cob if it's behind glass will allow air to
      circulate between the glass and the wall improving heating
      efficiency.  Covers can be installed over the holes to allow you to
      shutoff the flow of air.

    - Build the structure entirely of cob, then wrap the exterior in
      straw bales (or some other breathable insulation layer).  You
      could partially wrap it in bales and do the same exposed cob/glass
      wall approach above.

    - Try the new bale-cob hybrid wall system that Cob Cottage has been
      experimenting with.  Basically they build a cob wall that is
      completely integrated with an outer straw bale wall layer.  Because
      the cob is integrated with the bale portion of the wall, the cob wall
      can be thinner than you might otherwise make it, so that a single
      story building could be built with a hybrid wall that is about two
      feet thick.  There was an article about it a year ago in "The Cob
      Web" periodical put out by Cob Cottage Company.

It is important to note here that the insulation layer belongs OUTSIDE the 
cob wall, not inside as another message suggested.  If the cob is outside 
of the insulation, you have lost almost all of it's thermal stabilization 
and heat storage capabilities for your house.

Shannon C. Dealy      |               DeaTech Research Inc.
dealy at deatech.com     |          - Custom Software Development -
                       |    Embedded Systems, Real-time, Device Drivers
Phone: (800) 467-5820 | Networking, Scientific & Engineering Applications
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