Cob: RE: Domes ...

[goshawk at gnat.net]

Well I guess I should respond this one since I sort of the Nader guy.
I have worked on earthbag domes and in my own case got up so 
far and switched to fero-cement. I do have one small vault that is 
earthfill bags and then covered with cement and I've never had any 
trouble with water being traped. It's pretty well ventalated however. 

I think the earthbag domes are pertty stable, even in wet climates, 
if they are plastered with cement/stabalized earth, then coated with 
either a lime platere or white cement works good too. 

I live in middle GA and it gets a bit humid here as well as periods of 
rain. We get about 50 inches a year. A unplastered dome would 
most definiately fail over time here. Another option to plastering 
would be to stablize the bags as you mixed / filled them but boy 
that would be a lot of work. This will be the beginning of year three 
for me. But I work mostly alone, and on weekends/ evenings.  Thus 
the long time has more to do with me, but the manual effort should 
not be underestimated. 

I have had a section colapse, that was earthbag filled and 
uncovered, unplasted etc. It rained slow and steady for something 
like four or five days straight, then one morning I came down the hill 
and it had fell during the night. 

Another post mentioned a fellow out in California. They might have 
been referring to Ken Kern. From what I understand, he knew the 
structure was weak but was just checking it out to see how long 
before it colapsed. But the may just be folklore.

Cool guy regardless (IMHO).

Nader as several cement coated domes with earthfill bags 
(superadobe as he would call it) and well heck he lives in the 
desert, but they are holding up fine.

Enough for me,
I'm out of  here...
L&L




On 8 Dec 99, at 17:34, Raduazo at aol.com wrote:

>     It is possible to make earth domes using synthetic bags filled with
>     earth 
> and tamped into dome shape.  I think the bags are then coated with cement.
>  Whether this is safe or not is open to question.  Cement tends to trap
> moisture in the earth of cob and adobe.  I assume it would also trap
> moisture in these earth filled bags.  Whether these bags will accumulate
> enough moisture to cause catastrophic failure? That is the question. Ed
> 


Pat Newberry
http://www.gnat.net/~goshawk