[Cob] East Tennessee

[Shannon C. Dealy]

On Wed, 21 Jan 2004, Luanna Dycus wrote:

> Hi ET,
>
> I live in Crossville, TN.  I am waitng until the
> freeze and thaws are over this spring to begin my cob
> work.  Am I mistaken that freezing is detrimental to
> cob until is has set and dried?
>
> Lu

You are essentially correct, but it is not necessary for the cob to
completely dry before a freeze, it only has to dry enough that there are
sufficient spaces left (by the drying that has occurred so far) for the
remaining moisture to expand into when it freezes, so that the freezing
does not expand the cob and break it apart.  Unfortunately, it is
very difficult to tell when this is, but, particularly if you are in a
climate that is not subject to long really hard freezes, it is relatively
easy to protect the walls from the freeze (if you are in colder areas
there are still things you can do, but it is more difficult).  The main
things to keep in mind are:

  - The wall has alot of thermal mass, so it is going to take some
    time to freeze.  Of course the colder it is the faster it will freeze.

  - Simply enclosing an area (even in just a tent or plastic sheeting) can
    have a significant effect on the temperature of that area.

  - In most areas that are not subject to really extreme temperatures, It
    usually doesn't take alot of heat to keep an enclosed area above
    freezing.  A small propane heater or electric heater can go a long way
    to protect an area, particularly for short term freezes (though
    most propane heaters have the down side that they inject more water
    into the enclosure).

  - In an emergency, you could simply break open some straw bales and
    spread a thick layer of straw over the new cob which might be damaged
    by the freeze (though you will still want some kind of enclosure
    around it to keep wind and rain out).

FWIW.

Shannon C. Dealy      |               DeaTech Research Inc.
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