Cob: cob in the great white north?

[Fetter, Tom]

On the list from time to time, I've heard folks speaking about "cob in cold
climates."  Cold's a relative term, it seems - and I suppose it reflects
that most of the list members live far to the south of me!  But it seems to
me that by itself, cob's enormous thermal mass would only compensate for its
low R-value if the ambient temperature outside didn't stay frigid for long
periods.  Surely a thermal fly-wheel, however large, must be insulated in
really cold climates, even on the south side of the building.

Sooo ..... what's the best option?  Here in Edmonton Alberta, December
through February temperatures range from 10-40 below zero, with only a few
days at either end of winter with balmy above-freezing temps.  Has anybody
got beyond talking about cob/strawbale hybrids, and built one?  Would you
maybe put the cob structural wall on the inside, strawbales outside, and a
thin cob or mud plaster shell?  Would it be necessary to "pre-load" the
bales to compress them to account for eventual settling of the bales in a
hybrid as it is in more conventional strawbale construction, or would the
cob holding up one side of the bale prevent that settling?  God knows, the
cob won't settle!

Finally, does anybody know how well cob and/or earth plasters hold up in
rather severe freeze/thaw cycles?  Currently, when we face houses up here
with brick, the bricks must be fired at a high temperature to prevent them
taking up too much moisture close to freeze-up time.  Otherwise, the
moisture could cause the brick to crack and flake.  I'm concerned that
unfired mud could do the same, especially close to the ground where there
could be splashback from late fall rains, or damp from melting snowdrifts on
warm(ish) late winter days.  Having said all that, there are lots of lovely
80 year old brick houses 'round here, and the brick kilns probably weren't
blazing hot - maybe I'm over-concerned about nothing?

Tom Fetter.