How to Build an Earthbag Dome

Step 11 Build the Arch

You need a way to support the bags as you build the arch over the door. You could build an elaborate wood and plywood form. This might be worthwhile if you’re building lots of arches the same size. But this dome has just one arch, so we lashed two used tires together for the form. Build some supports on each side of the door opening to hold the tires at the correct height. Add some horizontal blocking to hold everything together, but leave enough space in the middle to squeeze through and for the string line that will determine your dome curvature. Note: you could temporarily fill the space with adobes, bricks, etc. and remove them later, but then you lose access to the dome and can’t use the string line.

It looks really complicated to build an arch, but it’s not. Make tapered earthbags about 12” high. Make sure you use the right soil mix that will withstand high pressure. Compact the bags from the sides and top as much as possible. The taper aligns with the center point of your form (the center of the tires in this case). You could use a string line for this or just eyeball it like I did.

Comments

[Arghus]

would it be a problem going up a floor? and in what country u build these houses?

[Owen Geiger]

The first floor can easily support a second floor, but lifting heavy soil high in the air is difficult. It would be more efficient to build a lightweight second story. Earthbag houses are being built all over the world. Our blog has readers from about 100 countries, and we've profiled completed projects in dozens of countries.

[D00M99]

Is there barbed wire between the bags on the arch?

[Owen Geiger]

No, only over the top, which continues around the whole dome.