House construction is affected by soil composition more than most people would expect. Approximately half of the composition of soil is water and air, both of which can be squeezed out of soil under the weight of a building. This loss of soil volume will cause the building to sink into the soil, creating serious structural issues. Houses built on hillsides are especially vulnerable to sinking into the soil if the right precautions are not taken. Soil must undergo compaction (removal of air) and consolidation (removal of water) with various tools, such as a jumping jack tamper, before it is firm enough to support a significant load. To find out more about this subject, take a look at this new, well-researched article by Kenton Shepard.