[Cob] Silverfish, Tornadoes, and Humidity -- and roof!

[Amanda Peck]

I hope someone else can tell us about the chains. And the roof.  Might be 
rain chains to keep water away from the door there, but unless it's running 
into an underground tank, I don't see why someone would want to run water 
off the roof to right there.  But there are some things ON the roof that 
MIGHT send the water down to the chains.

Don't know if the kind of roof has a name.  It's made of round wood, looks 
like it might be well insulated/ventilated.  In addition to the strange 
shape.  Which I gather you can "just do."   If you have a cooperative 
structural engineer.  Or a really good sense of how structure works.  
Without one--or both--of those resources, people tend to put a plate up at 
the top, to spread the load out over the cob between rafters/purlins, 
whatever, as well as directly under them.  Which they may well have done 
here as well, even if I can't see it.

...........

Carmen wondered about some Cob Cottage photographs. (snipped to the point 
that I thought I had to put the URLs for the pictures back in.)   Hilde's 
house:

http://www.cobworks.com/images/hilde/hildesoutsidehighview.jpg
and
http://www.cobworks.com/images/hilde/hildesoutsidefrontdoor.jpg


Would that be what the chains on this cob cottage are for?
  What  kind
of roof is that and is it very difficult to do? It looks almost like it is
rather precariously balanced, and yet it also looks very solid.