We primarily use Interlocking Stabilized Soil Blocks (ISSBs) also known as Interlocking Compressed Earth Blocks (ICEBs) that are made from compressed mixed soil, water, Portland cement and other additives using Hydraform's Patented ISSB machine. Typically, around 3,000 psi (21 MPa) is applied in compression, and the original soil volume is reduced by about half