To start with, building with earth is an unbelievably old construction technique, but this doesn’t stop it for being fantastic for contemporary building designs. Also referred to as rammed earth, this compressed building material has multiple construction properties, including being flexible in application and design. Moreover, it exemplifies low-tech building techniques.
How is rammed earth as a building material formed?
Rammed earth is formed from loose subsoil that is moist and compacted into manageable building layers. The compacting process compresses the material to about half its original depth through compelling the clay in the earth to bond with the aggregate. Since all this is done manually, there are no chemicals involved in the process. However, you do require a high enough clay content, approximately 15-30%.
Due to its simplicity and ease of production, rammed earth as a construction method has been popular all over the world. While rammed earth, adobe and cob were utilized decades ago, these conventional construction techniques are now being rediscovered by many sustainable construction companies in Hawaii. Rammed earth, in particular, is becoming ever more prevalent in contemporary architecture with the growing demand for green and sustainable buildings.
Environmental advantages of rammed earth buildings
There are multiple benefits to rammed earth buildings. In a majority of cases, building built with earth emits virtually no pollution and require low energy outputs. Moreover, rammed earth has very low embodied energy. The embodied energy of a brick is 6 times more than that of rammed earth. Here are these benefits in a brief summary.
The thick walls of rammed earth buildings are incredibly fire-resistant. How so, you might ask? Well, compressed earth has no flammable components on it and everything is so tightly packed that there is little chance of combustion.
Somewhat moisture resistant
And when a stabilizer is added to the building material, it effectively becomes resistant to moisture; however, continued exposure to water at the bottom and top of earth walls should be avoided.
Since compressed earth is quite dense, it offers enhanced levels of thermal mass. External walls of approximately 250 mm thick provide perfect protection from extremes in climate. The density and thickness of the building material means that cold or heat penetration of the wall is relatively slow. As a result, the internal temperatures inside the building remain comparatively stable.
Unfortunately, the thermal resistance of compressed earth is quite poor, meaning that its uses in external walls need to be minimized.
Compressed earth walls are relatively maintenance free. Moreover, there are feature that stand alone and don’t require finishing with wallpapers, paint, tiles, render, gyprock or anything else. Simply put, with rammed earth walls, there is no need to ever again spend money and time painting. Best of all, should a homeowner prefer any of these finishes, they can be applied to compressed earth walls in just the same way as to other masonry walls.
Since rammed earth walls are quite think, there is reduced noise penetration. As a result, this building material can be extremely helpful when it comes to providing sound insulation between areas in a building with different requirements, for instance between the sleeping and living areas, or between a family room and a study section in a home.
Many building developers are utilizing rammed earth in residential and commercial constructions of different styles and for multiple purposes. Variations in finish, color and texture are quite possible, and elements such as feature stones, alcoves, circular windows and relief details can be incorporated. Simply put, rammed earth is a natural product that blends beautifully with the environment and other natural building materials.
All in all, while the above list of rammed earth is not all inclusive, it will give you an idea as to why you should opt for this natural building material in your next construction project.