Make sure you get the basics right so your earthbag home is safe, sound and durable. As obvious as this seems, the most fundamental earthbag building principles sometimes get lost in the forest of information. That was one reason for writing the Earthbag Building Guide – to focus on the most important steps and demonstrate the best techniques in the right order of construction to avoid mistakes. A $20 investment in this book can easily save hundreds of dollars or more in wasted time and effort. (Same is true with just about any subject – knowledge is power.)
Key earthbag principles:
– Earthbags are not just bags of dirt or sand. Proper earthbags have enough clay in the soil to bind the aggregates together into a solid block.
– Use moist soil, not loose, dry soil.
– Earthbags are tamped solid, much like rammed earth. Once dry, they are similar to giant bricks.
– Avoid slumping corners by pre-tamping the soil (this is explained in my book)
– Overlap bags in a running bond, including at corners or use tubes
– Use barbed wire between courses for tensile strength and to prevent slippage
– Build straight, plumb and level (for rectilinear structures)
– Build uniform, smooth curves if building in the round
– Protect walls with a good foundation and a good roof with adequate roof overhang
– Raise the building site so water flows away from the building.
– Add reinforcing where necessary, especially on long, straight walls and at door and window openings
– Protect the bags from ultraviolet (UV) damage if your project will take more than a few weeks