Rammed earth walls are a mixture of locally quarried sub soils, portland cement and other pozzolans, small amounts of clays and silts, and frequently, iron oxides for enhanced color. Notably absent are organic materials. There is no topsoil in a rammed earth wall. There are no organic binders such as straw; so there is nothing to rot or support the growth of unhealthy organisms. The stabilized aggregate mixture is transformed by the ramming process into a durable masonry wall. Finding appropriate material close to the site involves rigorous testing.
Our walls exceed the minimum compressive strength required for commercial concrete and our materials are tested using the same protocols as is typical for commercial concrete walls. Each project starts with a detailed analysis of potential sub soils, followed by making test cylinders that are tested at an independent testing agency. Results are submitted to the Structural Engineer for approval prior to construction commencing.