[Cob] cob/insulation

[Robert Alcock]

Hi Bob,

In a climate as cold as Wisconsin, it sounds like you would want more 
insulation than could be provided by a wall consisting of woodchip in 
clay or lime matrix. Though I don't have specific figures, my feeling is 
that the matrix will provide plenty of continuous thermal bridging. 
Loose woodchip in a cavity wall sounds like a better option. Or since it 
sounds as if you've got a plentiful supply of other types of wood, you 
could go for cobwood (using woodchip as cavity insulation in between the 
inner and outer layers of cob).

If you did cobwood or else a strawbale structure plastered thickly with 
cob (like we are doing, in a far milder climate!), you could throw out 
the timber frame and avoid building a redundant loadbearing structure. 
(Sounds like you've made that decision already, though.)

Robert

www.abrazohouse.org

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> ------------------------------
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> Message: 5
> Date: Mon, 20 Apr 2009 00:44:01 -0500
> From: "Bob Smolen" <boka at mwt.net>
> Subject: [Cob] cob/insulation
> To: <coblist at deatech.com>
> Message-ID: <1DCC74DBD8724916828C21B46A84C891 at SmolenPC>
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> Because of the cold climate in Wi. , I am considering  a sandwhich of cob with woodchips in the middle. This will be an infill for a timberframe structure. What is the best way to build ? I assume boards or plywood could be used to support a 4 to 6in cob wall between the timbers and then the forms could be stripped and used to support an exterior cob walll say 6 to 8 inches away from the first wall after which wood chips would be placed into the space between. Alternatively, after the first wall is built,the forms could be used as an outer support as a temporary wall and the woodchips poured between the cob and the form. After the woodchips (coated in light clay) dry and firm up, the outer cob wall could be built against the chips.
> Does anyone have any experience with this method?
> I guess cob is not necessary as a chip wall could be made between forms and then coated with a clay lime plaster because the wall is not load bearing and no need for cob. I have had problems getting the chips to firm up enough to be a basis for a wall. Has anyone worked with wood chips? A friend is a logger so I have access to unlimited amounts. I have a skidsteer and can produce a lot of cob working alone. That is why I am considering cob. 
> Thanks,
> Bob
>
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