Cob: how cold can you go?

[Darel Henman]

Jen,


jen walker wrote:
> 
> Hello cob afficionados,
> We were really excited to receive our copy of the Hand Sculpted House which
> is wonderfully inspirational reading. We'd love to build a cob house in West
> Quebec for us and our two small boys. Our intended location is the
> beautiful Ottawa Valley-actually, up the valley in the hills. We nearly have
> the money raised for the land. It gets cold here, as low as -40 degrees
> celsius (I'm not sure what that is in Fahrenheit)

It's the same -40 degrees F.  Which is about as cold as the North Pole.

> however, the winter
> weather is more often in the vicinity of -10 to -20 and is often blazingly
> sunny for days on end. Also, a lot of snow is sure to fall. We are only a 2
> hour drive north of the border with New York. Its definitely the frigid
> hinterland but its not Winnipeg where I believe temps can be as low as -60.
> My question is, could a cob house be insulative enough in this locale,
> perhaps if built on a south facing slope? Does any one really know as yet?

I recommend that you refer to some of the earthship houses that have
been built at high altitude areas, in the U.S., these are cold areas.
 
A lot depends on your design.  I would probably put strawbale or a light
clay additional insulation wall on the outside of the cob, and then add
a eathern berm with an underground umbrella to shed water away.  Some
put insulation underthis to keep the warmth in the ground from getting
out to sound.  Put these at least on the coldest side of the house, in
your case probably north.   

Another good idea would be to build into a south facing hill.  This
might preclude the use of cob for the inside areas, though.

Check the climate data, because if you have a lot of sunny days in the
winter, it would make a big difference.  Also the number of cloudy days
in a spell, would give you a worst case scenario for being without solar
energy.   Talk to people with cellars and basements in your area to see
what the average temperature are down there, without directly added
heat.

> Thanks in advance for any thoughts on this matter
> 
> Jen Walker, Andy Daub & family

Darel