[Cob] More on earthbag foundations

[David Elfstrom]

There's been two buildings done in Ontario, Canada with earthbag 
foundations, both by the sustainable building students at Fleming College.

I worked on the second one, for the Kinark sustainable living centre.

Photos are at http://www.sustainablebuilding2006.ca , click on 
Construction Photo Gallery.
Look at the photos for weeks 2 and 3.

We did both a single wall version and a double wall version.

The double wall version is illustrated here:
http://www.sustainablebuilding2006.ca/gallery/main.php?g2_itemId=1989

We have a sill gasket on top of the earthbag, beneath the sill plate, to 
prevent wicking. In the double-wall version we have placed some recycled 
EPS as a thermal break.

Flashing is placed on the outside. For the inside, fill was brought in 
to raise the floor to the sill plate level.
For the rounded foundation wall, we meshed and then stuccoed the outside 
of the earthbag.

The outside of this foundation has a skirt of EPS boards, in what is 
called a shallow frost-protected foundation.

The mix in the earthbags was sand, clay, stone and a bit of cement.

If you have any questions, drop me a line.

David Elfstrom, P.Eng.
Residential Sustainability Engineer
Toronto