Jeremy Bunag wrote:But I'm imagining something like sandbags (or dirtbags) stacked up, with little fissures for air to infiltrate.
Seems to me that that is the last thing to worry about with this kind of construction. Earth bags are the exact same thing as sand bags used to hold back flood waters. Indeed most 'sand bagging' uses local soil rather than sand. Those hand stacked bags lock into each other so tightly that water can't get through even though the bag is made of open weave plastic and filled with permeable soil.
Thermal mass structures, especially in 4 season zones, are improved with insulation on the outside. I read of using vermiculite or expanded perlite render to plaster the exterior walls. But the discussion of rice hulls got me thinking - what about an outer row of rice hull bags next to the soil bags? Would they be stable enough to apply an external cob render over them?
There are immense quantities of shredded wood chips/mulch (not talking about leaf mulch) in many areas. A lot is used in gardening as ground cover. But the supply is nearly free if you have a chipper and brush to clear, or are willing to haul it away for others. Would this be useful in bags? It would be a lot better insulator than as thermal mass, and you'd need to be extra careful in providing a vapor barrier. Seems like it could compliment cordwood construction using on site dead trees and underbrush as building material. Most trees aren't suitable for lumber, but they could still provide useful building material.
hello i am myself ,a city dweller who is experimenting with bagged-dirt wall building...i have no construction experience..the only thngs i'm really 'skilled' at are art and music....but my backyard is kind-of private and so i've decided to build an earth-cave-like structure out of mud/clay-and dirtbags also lots of fallen-treebranches...basically i use just about anythng i can use from mother-earth herself..that's FREE of cost to me...i like to recycle as much as possible so paper and trash get burned and reused into my mudmixes....soo..here i have this man-made cave looking structure in my backyard where there is a firepit in the back-end of it((completly enclosed in mud/dirt))...anyways...last couple winters i was out burning tree branches and papertrash in my cave...and most of the heat stayed in my cave...somtimes i walk around on the outside of it to see if i can feel any heat escaping anywhere....but nope...outside walls are dry and cool...it's rather primitive looking..but at least it works..