[Greenbuilding] Earth block wall section

[Chris Green]

Stephen Collette wrote:
>
> My concerns are the spray foam and adobe together. I'm a bit hesitant  
> on that combination. But I don't  know how well the two materials  
> will play together. His other questions are minor to the fact of  
> whether this wall system would actually function in a varied climate  
> such as ours.
>   
I think CEB's can be compacted a lot more than adobes. That may or may 
not have an  impact on how the foam works with or against the earth, and 
I haven't run across and tests in English discussing how the more 
compressed blocks absorb moisture.  As long as the block withstands 300 
pounds psi, it can be used as if it were loadbearing masonry. IIRC, some 
of the CEB's exceed 3,000 psi. Maybe even more.
As for the foam...perhaps placing a 1/2" layer of rigid foam insul 
between the earthen blocks and the foam would be worth considering.
The problem is that you'd either need some kind of form on the outside 
to help shape the spray foam, or end up shaving a lot of bumps off.
Might be a good idea to build a 4x8' test wall first to work out the 
techniques.
Maybe a better idea to just glue the rigid foam on to the blocks with a 
sticky clay or lime/clay plaster?

Simon referred to the S.I.R.E. wall method developed by Meror Krayenhoff 
and Terra Firma Builders.  S.I.R.E.wall involves having the rigid foam 
at the core of the wall structure, but since Simon's thinking of using 
an exterior siding, he should know that other designers have placed 
insulation on the outside: this leaves the whole of earthen mass to work 
as a thermal fly wheel.
I believe some have placed it on the interior side, but I don't have any 
links to show any such buildings.
Placing the insulation in the core, as in the S.I.R.E.wall method, 
allows the layered aesthetic to be seen on both sides. Placing it on the 
outside and using siding allows the addition to retain the character of 
the rest of the existing building.
So it ends up being an aesthetic choice.
The Terra Firma link:
http://www.terrafirmabuilders.ca/index.html

and the S.I.R.E.wall homepage:
http://www.sirewall.com/

Check the second to last entry at earth architecture.org for a short 
post about a CEB's wall house in Utah.
http://www.eartharchitecture.org/
When you follow the link to the builders' blog about this house, you'll 
note they sprayed the blocks with some kind of silicon spray, probably 
waterglass. This is the first time I've seen a mention of this treatment 
anywhere.
As for an interior finish, a clay, clay/lime, or natural lime plaster 
should all be suitable. Using a silicon paint on the plaster will reduce 
the amount of moisture passing into the wall. 
Not that that is going to be a big problem.

For strait rammed earth construction in Ontario, check out this place:
> St. Thomas Church, Shanty Bay, Ontario, 1842. One of the oldest 
> remaining buildings constructed of rammed earth in Ontario
http://www.cdnarchitect.com/asf/enclosure_design_strategies/precedent_vs_innovation/precedent_vs_innovation.htm
The quote is a caption to one of the pictures of rammed earth structures 
discussed on this page.
I don't know how far Shanty Bay is from Peterborough, but it might be 
close enough to justify a trip over for an inspection.

The above quote implies there are other rammed earth buildings in 
Ontario... :-) I wouldn't hazard a guess as to their thermal 
performance, but 165 years proves the buildings are durable in that 
environment.

There are also "old" rammed earth buildings with wood siding on them in 
upstate New York and some on the Michigan penninsula. I believe it was 
Mr. Peipkorn who mentioned some of these and stated that sometimes the 
occupants aren't even aware they are living in earthen houses.
I don't have any links for these at this moment, but I think other 
members will.


Links which might be of interest:
Understanding Stabilized Earth Block Construction Using the Cinva-Ram, 
by Nils Gore, Assistant Professor, University of Kansas School of 
Architecture and Urban Design (page from 2000...)
http://www.kubuildingtech.org/ngore//nilsweb/cinvablocks/index.html

University of Kassel's Building Research Center, in Germany. One of the 
centers of the modern earthbuilding universe. Gernot Minke is the director.
http://www.asl.uni-kassel.de/~feb/Welcome_e.html 
<http://www.asl.uni-kassel.de/%7Efeb/Welcome_e.html>

An ebook entitled:  
Construction Manual for Earthquake-Resistant Houses Built of Earth is 
available for downloading at:
http://www.crystal-netbook.info/e126290/e129776/index_eng.html
Author is Gernot Minke.

RedVector has a 3-hour online course entitled: Alternative Construction: 
Rammed & Modular Earth
The course number is RV-6349 if you want to do a search of their courses at:
http://www.redvector.com/LMS20/Account/Order/ShopCart/CourseCatalog.aspx
Better yet, us the TinyURL link to go strait to the above course's 
description:
*http://tinyurl.com/2t93w3*

Engineers, Architects, and people in similar professions can earn 3 life 
learning credits for taking this course, depending on which association 
they belong to. Check the listings on the page with the course 
description. ** <http://tinyurl.com/2t93w3>


Cheers,

Chris Green.



<http://www.sirewall.com/>