Hello all, I thought I’d write a bit of an introduction to “earthbag” houses, since I had the brilliant experience of staying in one while at Kirinosato Takahara! All the photos in here are mine, of my little temporary home in the mountains. I had never heard of earthbag houses until I read Jian’s WWOOF host profile and noted that their volunteers (ideally one at a time!) sleep in an earthbag house next to the main hotel. I was intrigued, and keen to try it out! Here it is: | |
1. Prepare your building site, i.e. clear and level the ground, remove topsoil and position fill around the construction area to minimise fetching and carrying when making the bags. Dig a trench to stabilise the subsoil, and in it pour about 12 inches of gravel. Add corner guides and stringlines. 2. Collect together the things you’ll need: bags, buckets and a chute, gravel, the filler, a hammer and chisel, various types of wire (see website for a proper list ;) The filler will vary depending on the construction; Jian’s consisted of soil, sand, cement powder and water. |
3. Gravel is used to fill the bags that form the foundations and lower “courses”, or layers. These initial “bricks” will be double-bagged for strength. Fill each to about 90%; this should mean that the bags are all filled to capacity and all the same size, which in turn should make it easier to get the walls level. 4. Decide on and mark the door opening! Then place the bags in an initial layer, first positioning, then filling, then sewing each. Start from the corners/openings and work towards the centre. When the first layer or course is fully laid, tamp it down all over by walking on it and pressing the bags flat using a flat piece of metal on the end of a pole. Each layer should be solid and level before work begins on the next. |
5. When the first layer is solid and level, add two strands of four-point barbed wire along the top, holding the wire down with bricks as you go. This wire strengthens the wall and helps prevent slippage, and should be used between all layers. Jian, however, opted for an alternative approach, which I imagine can only work if you’re doing all this really fast and the bag contents are still fairly soft! His team used metal rods to “stake” the circle at a number of points, driving each rod downwards as deep as possible into the foundations (which would also need to be soft, still...). 6. If you’re going for the barbed wire method, you’ll need to use a metal slider between the new bags and the barbed wire as you lay subsequent courses, so the wire doesn’t tear the bags. So fill and sew each bag with it on the slider, then tilt the bag, slide the end into position against its neighbour, and yank the slider out from under it. |
7. Continue filling and sewing the bags, and when the wall is high enough to be safely above the risk of rising moisture: probably at least three layers above ground level, it’s time to switch from gravel to filler. This would also be a good time to think about where you want your windows ;) So now, turn each bag inside out before filling, so the corners don’t protrude, and lightly tamp down the bag contents after tipping in each bucketful, and after sewing the bag closed. 8. Continue laying each course, remembering the barbed wire each time, and if you ARE working fast you could also push some stakes in, à la Jian, to “pin” multiple layers together! |
Jian and co used 1300 brick-sized bags altogether, and it took four months from start to finish. The outer coating is also earth-based, but rendered waterproof by adding cement to the mix. For the roof of an earthbag house, one option is a “living roof” of moss, grass and plants – beautiful, and a butterfly haven when the flowers are out! The roof of Jian’s house is made of Japanese red pine and has a stained-glass skylight... when the sun streams in this window casts a beautiful coloured pattern on the inside wall :) |