Rammed earth is a method of building walls whereby a mixture of earth is compacted in layers between forms. Each layer of earth is approximately 15 cm (6 inches) deep. As each form is filled, another form is placed above it, and the process begins again. This is continued until the desired wall height is achieved. Forms can be stripped off as soon as the form above is begun, as the compressed earth wall is self-supporting immediately. Most rammed earth builders in Australia, including our company, use pneumatic rammers to compact the earth within the forms.
The soil mix needs to be carefully balanced between clay, sand and aggregate. The clay and moisture content of rammed earth is relatively low compared to that used for mud brick or other earth building methods.
A wider range of soils are suitable when a small amount of cement is added to the mix. Most rammed earth builders in Australia add some cement. The result, known as ‘stabilised rammed earth’, is a strong masonry product which provides excellent thermal mass.
Massachusetts Institute of Technology - Earth Wall and Joe Dahmen are working research of Rammed Wall building
