Cob: healthy home data

[Shannon C. Dealy]

On Mon, 31 Jul 2000, Arthur Petch wrote:

[snip]
> Issue eight, spring 19999 of the CobWeb suggests in an article by Ianto
> Evans that cob is toxic free, but there seems to be some suggestion in a
> past emails that mold may be a problem
> [http://www.deatech.com/natural/coblist/coblist-web/1998/0917.html].
> Molds can be very toxic.  Does anyone have any experience with this
> problem?
[snip]

While the referred to posting suggests that the clay is the source of the
mold, a close examination (which I have done on several occasions) will
show that the mold/fungus/whatever-it-is is always growing on a piece of
the straw (or whatever fiberous material you are using in your mix) that
is at the surface of the wall.  Probably the handling of the mix tends to
smear a bit of clay and visually obscure much of the surface fibers, but
there is still alot of straw right at the surface of the wall.  I can't
say what kind of growth this is, but I have only seen it occur while the
wall is initially being built, and generally only while building at cooler
times of the year when it takes much longer for the wall to dry.  After
the wall has dried more and loses it's "damp earth" look, the growth seems
to disappear.

For what it's worth, I have seen similar looking growths (mold/whatever)
on the ground around here (Western Oregon) in the late fall when things
start getting cool and wet, so even without being in a damp freshly built
cob house in this area, you probably would get lots of exposure to
whatever it is every year.


Shannon C. Dealy      |               DeaTech Research Inc.
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