Cob Re: Work in Georgia last weekend

[Patrick Newberry]

Just to fill everyone in...
 
A group of about 12 folks got together here in Mauk Georgia and did a 
large amount of work on our large dome. The walls of the 22 ft. 
diameter circle are now over 5 feet high.  Being that I 
normally work alone I was awed at the amount of work completed with 
the group. I also was filled with  a lot of gratitude. My family 
and I felt truly blessed. 

During the day I was able to answer a lot of questions 
concerning cob and superadobe, but one phrase kept coming to mind. 
"Give a cob house a good pair of shoes and a good hat and she'll last 
you forever" 
(or words to that effect)

This has lead to me to re-think the upper reaches of the house. That 
is the center dome. Carrying that amount of earth  up to the 
approximately 22 feet height is a bit overwhelming. But at the same 
time I wouldn't mind keeping it's general shape  as some kind of dome 
just to stay true to the architectural style of superadobe. I have an 
idea in mind that may be the answer. Once I get to roof level (by the 
end of next month) I plan on building a double thin shelled dome with 
Liechtlehmbau (light clay) infill. I'm doing a proto- type over my 
well pump right now. On the wall itself I'll put a bond beam with 
some wood blocks bolted into this bond beam. If any of you have seen 
a sweat lodge made from saplings then visualize that. I'll take some 
of the scrub oaks growing on the land and bolt them around the dome on 
the inner side of the bond bean to the wood blocks. Then pull the 
tops of these sapling to the center of the dome. On this I'll take 
discarded carpet and lay it over the sapling form. I'll cement this 
by rubbing cement into the carpet fibers. Basically a ferro- cement 
shell. The building I'm in now is built using this cemented carpet for 
the walls and roof. I've been working out of it for over a year now 
and did have to go back over it once to fix a few small cracks but it 
has been sturdy enough to walk on! Next I may put a bit of tar paper 
over the clay coated straw then another ferro-cement shell. On the 
inside of the dome between the saplings I'll have to plaster - more 
than likely with a lime earth plaster.  I'll leave the saplings 
somewhat exposed. Then I'll end up with a much lighter weight 
roof-dome than I would have with the superadobe. 

Now on the outer wall I plan on having a 4 ft. overhang and will use 
earth plasters here. HONEST, I'm trying not to use cement! I'm just 
trying to make the roof very fire resistant as we are so deep in the 
woods and if a fire were to start, you'd be in trouble with a 
thatched roof! Since money is a factor this seem to be a good option.

Lastly on the outer wall, I'm going to build it using the bags a bit 
like  the Roman aquaducts. That is to say a series of arches 
supporting a bond beam which in turn will support the roof (the roof 
from the outer wall to the inner dome. The open spaces between the 
arches will be used to place windows or doors or they will be 
just be filled in with cob or lightweight straw/clay and can be 
reopened latter with out affecting the structural integrity of the 
wall.

And really really lastly, in the section that were are "redoing". 
That is the foyer, we plan on putting in a 4 x 4 x 8 fish tank to do 
a bit of aquaculture. Bags and ferro- cement here to build the tank. 

Hope that wasn't too confusing a description.  


Latter, 
Pat
http://www.gnat.net/~goshawk
(site has floor plans if the above was too hard to visualize)