Cob: <no subject>

[Shannon C. Dealy]

On Tue, 24 Dec 2002, jen walker wrote:

[snip]
> difference. I was wondering, since single panes would be easier to salvage
> or make etc. if any of you out there know if they'd be o.k. in very cold
> winters with of course heavy curtains after the solar gain from them was
> done for the day. Perhaps they'd get too frosty.

You might try an alternative approach that I have heard of and am about to
try myself, set multiple single panes of glass into the cob.  Many people
have embedded single panes of glass directly into cob walls while they are
building them, at least one person I have heard of put two panes a short
distance apart to create their own double pane windows.  To embed a single
pane, put duct tape or something similar around the edges of the glass so
you don't cut yourself, then set it on the wall and build up slowly around
it, giving the cob around the glass plenty of drying time as you build it
up so that it doesn't put weight on the glass and break it (particularly
as you get to the top of the glass).  Basically you are trying to build so
that (except for the first layer of cob) the cob around the glass is
always providing all of the support for each new layer of cob.  I don't
recall if the person gave details on how they did multiple panes, but my
plan is to build in just a single pane, but make the opening for the glass
larger an inch or so from the single pane, and let the cob dry fairly
completely before doing anything more.  Once the cob has dried, I will put
another pane into the side where I left the opening wider, and then add
cob all around the interior of the opening to hold the additional pane in
place.  By doing it this way, I will be able to clean the single pane
before adding the second one (it would be a real problem if you put both
panes in at once and as you were cobbing over the top some cob fell
between the panes and smeared a little dirt between the panes), and if the
cob is dry enough around the glass before the second pane is set in place,
the cob will hopefully absorb any excess moisture between the panes before
it condenses between the panes and leaves streaks on the glass.  The
person I had heard of who had done this reported there were no problems
with condensation between the panes, but I don't recall where they were
building, and this may not work in all climates.  You could of course also
do this by cutting a hole in a dried cob wall and setting the panes one at
a time into the cob, though one of the advantages (for single panes
anyway) of embedding directly into the cob is you don't need to cut the
glass, you just stick it into the cob, and then cob around it in the shape
you want the glass to appear to be.  You can still do this when adding the
glass later, but you may need to cut a somewhat larger hole in the wall
and or cut the glass down a bit in order to achieve the desired result.

Presumably this approach could work with any number of glass panes,
allowing you to achieve a fairly high efficiency window, though the
possibility of condensation between the panes in different climates
remains an open issue.

Shannon C. Dealy      |               DeaTech Research Inc.
dealy at deatech.com     |          - Custom Software Development -
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