Cob: Re: Insulation etc

[maureen & dale smith]

off list please

Mike Holland wrote:

> Sojourner wrote:
>
> >Would the wood embedded in the walls have to be PT?  Or would normal
> <untreated wood be ok, since the walls will not actually be wet (better
> >not be!)  This would act like vertical "lathe", like they used to use
> >for plastering.
>
> Just for reference, one of the internal walls we removed was built with
> vertical posts about 2 foot apart, with split oak laths nailed to them - the
> kitchen ceiling/attic floor the same: the laths and posts had been there for
> anything up to a century and showed no particular signs of rot or insect
> attack.  I strongly doubt that they were treated in any way.  The lime in
> the cob mix used round here tends to dissuade insects, anyway.
>
> >Would you have to take special steps to make certain that the cob mix
> >would hold with the weight of the "lathe" and the siding?
>
> Then again, if you were going to go down this route, you might as well put
> up a wooden framework against the cob wall once dry, and nail your
> plasterboard/plywood/whatever to it - avoid the issue of the wall to lath
> cohesion.  We're actually using a steel framework in the bathroom area, if
> only because it's quick.  I don't enormously like the very smooth surface
> this type of system gives you - it's somewhat at odds with the "not a
> straight line nor right angle in sight" aspect of the rest of the house, but
> you have to balance aesthetics with convenience sometimes - and in any case,
> we can always lob some of the hemp/lime render on it later to soften the
> edges, if we feel like it...
>
> Mike