Cob in cold climes

[David Knapp]

Great photo's Will.  I could use a whole neighborhood of them instead of the vinyl sided tract-built jungle that is going up right now in the previously empty cornfield across from my house.

The pictures are good enough to eat!  You ought to repost your message to the ESSA list as well.

This is something to dream about while I work some "free" overtime on this Sunday morning (the only time I can get my work done due to the constant (phone) interruptions during the week.

I have some questions for you regarding your sb modifications you would perhaps make.  Any guesses how thick you'd make the interior cob wall section (next to the sb)?  Would it be straight or tapered?  Normally the inside is straight and outside tapered, but in this case it requires a different approach I guess.  Would the sb or cob section (or both) be the load bearing part?

Thanks for the sunshine,

Dave

>>> "Will Firstbrook" <wfirstbr%direct.ca at internet.rkd.snds.com> 03/21 4:29 AM >>>
Hi Dave & Paul,

I agree with the strawbale & cob approach for the colder climates in Canada
& US. Personally I'm going to build the organically curved walls out of
bent bales of straw pined together with sharpened bamboo spikes. Then put a
thick layer of cob on the inside and a cob plaster on the outside. Part of
it will be load bearing. In this way we get the high mass benefits of cob
with the great insulation value of strawbale on the North, East & West
sides. The only drawback is the walls are going to be 2 to 3' thick. I will
just use cob and lots of windows on the South side. 

Regarding the living roof. I visited Patrick's gorgeous cob cottage on
Mayne Island last week and took a few pictures. This was the 1st code
approved cob house in Canada. The way he got it approved was to get some of
the building inspectors on the island in the cob workshop he hosted. After
feeding them info on cob & strawbale for the last 5 years to spark their
interest. I just scanned the pictures and put them on my web site. If you
are interested you can find the pictures at:
http://www.geocities.com/RainForest/Canopy/7148/pat_cob.html . I was
introduced to Patrick at Robert Bolman's great slideshow presentation in
Vancouver. This cob cottage is located in the warmest and probably the
wettest location in Canada. I don't think it would be warm enough in some
of the colder parts of Canada. But this place has a warm relaxed beauty
that I found intriguing.

Regards,
Will

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From: David Knapp <DMKnapp at mail.rkd.snds.com>
To: coblist at deatech.com 
Subject: Re: Cob in cold climes
Date: Saturday, March 20, 1999 3:52 AM

paul,

i too have been contemplating solutions for our northern midwest winters in
Illinois.  your 2 x 4's would have to have some type of deadmen attached to
them like what they show in the cob books so that they won't pull out. 
this would be quite allot of work, but is possible.

my experience is extremely limited, but have been wanted to move toward
using only earth/people friendly materials as possible.  i have heard from
several knowledgeable folks that it probably work very well to use a straw
bale wall on the north and west (and possible the east walls in 9,000
degree year heating climates).  cob bonds very well to straw bale wall
sections when the appropriate planning is use.  i am also toying with the
idea of a living roof, with some type of timber-framed structure.  this
would be compensate for our very hot and humid summer.  the winter snow
load on the living roof also would tend to help the insulation value of the
roof too.  rob roy, of the cordwood masonry fame has written extensively on
how he does this.  perhaps you can borrow a few of his ideas and
incorporate them into your plan.

dave
winnebago, illinois
http://www.bigfoot.com/~renewables/ 

>>> "Paul Procure" <tempo%nrtco.net at internet.rkd.snds.com> 03/19 5:41 PM
>>>
As has been discussed on numerous occasions it appears that cob has no
great R-value (something like 0.25 per inch).  I was thinking about the
possibility of embedding two-by-eight studs into the cob mixture during
construction leaving a four inch ridge into which I would put fiberglass or
some other insulator. 

 What possible adhesive problems would I have between the cob and the wood
i.e. might the wood pull out of the wall?  Any other suggestions for
Canadians in North America's attic?

Paul Procure

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