ABSTRACT
Moisture from the ground will penetrate into a building either up into the walls and floors by capillary attraction or through the structure of basements by hydrostatic pressure. In some parts of the country radon gas occurs naturally in the ground. In other areas where landfill has taken place, methane and carbon dioxide gases are to be found as a result of the action of anaerobic micro-organisms on biodegradable materials. Gases similar to landfill gas can also arise naturally. As the ground below the site of a building may suffer from a number of inherent causes of instability, such as geological faults, unstable strata, and disused mines, it is necessary to carry out a thorough site investigation before detailing any foundations for a large building. The level at which the strip is placed in the ground is determined by the nature of the soil and the need to avoid movement.
