[Cob] Seattle Area Cottage Update

[Leslie Moyer]

Wow!  Beautiful stuff!  I hope you'll continue to send photo updates.

 From reading I've done on cordwood (no actual experience), there is a 
school of thought that now suggests a 3-year drying time on wood before 
incorporating it into a structure.  Wood dries slowly--needing time for 
the moisture inside to move out where it can be evaporated off.  This 
means the wood continues to shrink until all of the moisture is gone.  
One recent suggestion I saw was to use a saw to cut down to the center 
of the tree, thereby allowing the inside to dry as quickly as the 
outside and thus prevent "checking" (the v-shaped cracks that form).  
Supposedly when the wood is completely dry, the crack will self-close.  
Checking forms because the outside dries and shrinks before the inside 
can dry and shrink, too.  Even those who say that the wood only needs to 
dry 6-12 months will tell you that the wood WILL continue to dry for 
quite some time after you've built the structure & tell you you will 
need to caulk around each log once it is completely dry.  It makes more 
sense to me to wait until it is dry in the first place. 

Personally, I love the look of cordwood but ruled it out because 
wood--throughout its lifetime--expands and contracts too easily, 
allowing cracks to form where the wood meets the mortar (or whatever you 
use to fill the cracks between logs).  Cracks = air infiltration.  If I 
were using cordwood, I would plaster over either the inside or the 
outside--or both.  But then it doesn't look like cordwood anymore.  
Another possibility is to build two walls parallel to one another with 
some sort of insulation in-between. 

As for drying times of cordwood vs. cob, I don't really know the 
answer--someone else surely will.  I know that wood will draw some of 
the moisture out of cob when the two materials are placed together, but 
it probably depends on how dry your wood was to start with.

After I looked at your photos, it looked like maybe air infiltration 
wouldn't be an issue in this particular project anyway.  What will be 
the function of the structure you're building?

--Leslie



Dulane wrote:
> Here's an update of my cottage, photo links below.
>
> We're working under a tarp, because the weather has changed. Sure slows down 
> the drying time!
>
> I'm switching to a cordwood design after I get over the door and window 
> lintels and get the loft beams in. Gotta get this done before the hard 
> freezes! Yikes.
>
> I've heard that cordwood dries faster than straight cob. My wood came from 
> last year's wind storm, and is almost dry...but I'm just getting it peeled 
> now.
>
> Any input on drying time for cordwood vs cob?
>
> http://s151.photobucket.com/albums/s143/Dulanec/?action=view&current=Tarp1.jpg
>
> http://s151.photobucket.com/albums/s143/Dulanec/?action=view&current=Sun.jpg
>
> http://s151.photobucket.com/albums/s143/Dulanec/?action=view&current=Sunflower.jpg
>
>
> "If man makes it, don't eat it."
> Jack La Lanne 
>
>
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