Monthly Archives: October 2014

Mini Earth Bag Dome Duck House

I’ve been wanting to make an earth bag dome forever (and click that link if you want to know what the heck that is or how to do one right!)  I’ve been saving poly woven bags since my days collecting soil samples in them for work.  I finally had a project to use them for: there are too many poultry on site to shove them all back into my chicken house for the winter so I needed to make a duck house.  I have 5 Muscovies now, and even though they need less protection than chickens in general,  it’s extreme enough in Anchorage that they needed a warm place to sleep in the winter. IMG_4034 I started by shoveling off the turf and topsoil (less than 6 inches) in a circle.  I scribed the circle with a stick on a string attached to a centrally placed pole.  Then I filled bags with the gravelliest soil I could find on my lot.  The inside diameter of this first ring is a little less than 4 feet. IMG_4039 I was running low on gravelly soil, so I went to the home improvement store and bought about $40 of pea gravel (10 bags) to do the next level.  This creates a barrier to moisture wicking up into the rest of the structure. Then I had the brilliant idea of using wood chips in the rest of the bags instead of soil.  Mostly because they are lighter and easier to move and I have a ton of them.  They would be more insulating that soil…think straw bale, kind of.  They would not have the strength of soil bags though, and have a high danger of decomposition and the resulting instability.  I also had 7 bags of ready mix concrete that were getting a little solid from sitting around for a while. Maybe woodchipcrete would be a little more stable?  SO I mixed in one 50 lb sack per wheel barrow load: IMG_4048   IMG_4049   This worked for most of the layers in the dome, until I ran out of concrete mix for the last couple of layers, but everything seems pretty stable…for now. IMG_4067 Here is a selfie of me standing on the top: IMG_4069 And here is a door detail: IMG_4061 I used a big cottonwood log as a form for the door, but it wasn’t as wide as the bags so things did settle to a little smaller than I would have liked, but still big enough for a duck. Then I covered everything with 6-mil poly (builders plastic/visqueen) to hopefully keep the rotting to a minimum: IMG_4071 And threw the top soil and turf back on: IMG_4085 And lo and behold, after baiting it with some canned salmon, the ducks finally trusted it enough to go in at night! IMG_4092 So we’ll see (and I’ll let you know) how things go. There is no ventilation other than the doorway. I will have to pull the poopy bedding out with a potato fork since even a rake is too big to get through the door. If they lay eggs in there that I don’t want them to hatch, it’ll be fun trying to get them out. My moisture management could fail miserably and things could settle or collapse in catastrophic ways (which could lead to a big pot of duck stew in a worst case scenario). I will have to shovel snow out of the entry. Next year I’ll have to get some sort of stucco over the non-dirt covered part of the entry so that it doesn’t photodegrade. It really didn’t take much time, energy, money, or materials to build, so I figure the risk is low for this experiment!

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