Quick Answer
Constructing a rammed earth wall involves excavating a trench, mixing a mixture of soil, sand, and water to the right consistency, and then compacting the mixture into a form using a tamper or hand tamp. The mixture is compacted in layers, with each layer being tamped to a depth of about 4-6 inches. The process is repeated until the desired wall height is reached.
Preparing the Site
To build a rammed earth wall for an earthship home, begin by excavating a trench 12-18 inches deep and 18-24 inches wide. The trench should be compacted to a stable base using a hand tamper or plate compactor. Next, mix a blend of local soil, sand, and water to create a workable mixture, ideally with a consistency similar to wet concrete.
Mixing and Compacting the Earth Mixture
The earth mixture should be mixed in small batches to prevent over-mixing, which can lead to a weak or brittle final product. A 1:1:1 ratio of soil to sand to water is a common starting point, though this may need to be adjusted based on the specific soil conditions. Using a hand tamper or mechanical tamper, compact the mixture into the excavated trench in 4-6 inch layers, vibrating the tamper to ensure thorough compaction. Repeat this process until the desired wall height is reached.
Finishing the Wall
Once the wall is built to the desired height, use a level to ensure it is plumb and a straightedge to check for any deviations from straight. A layer of compacted soil or sand can be applied to the exterior surface to provide a smooth finish. If desired, a plaster or render can be applied to the exterior surface to provide additional protection and aesthetic appeal.
Find more answers
Browse the full Q&A library by topic, or jump back to the topic this question belongs to.