How to make
a rammed earth block

Keep in mind...

Rammed earth uses subsoil—the layer beneath topsoil, 2-3 feet down —made up mostly of sand, gravel, and clay. The ideal ratio is around 30–40% clay to 60–70% sand and aggregates, but for temporary projects, precision isn’t essential. To test your soil, mix it with water in a jar, shake well, and let it settle for 24 hours to see the layers.

1 / Set up for form

Arrange your four pieces of wood to form a square in the middle for the dirt to go. Use the clamps to secure the form in place

2 / Prepare the material

Add the dirt to a bowl, slowly pouring in water and mix. The ratio will be about 85% dirt 15% water, but may be less if the dirt is already moist. The test for the right consistency will be when you can condense some in hand making a fist. If it keeps its form its ready.

3 / Ramming

Dump 2-3 cups of dirt into the form. Condense using a few lighting tapping motion to even out the layer, then several hard rams all over. repeat until the form is full over dirt. When complete remove the form and allow it to air dry