It can be said that, in general, there are no residual soils in Canada- certainly none that will be encountered in ordinary building operations. Types of Soils Soils are generally described and defined by the size of the particles of which they are constituted. Sand, for example, is readily recognizable as consisting of small particles which are easily seen by eye. Silts are soils which are made up of particles finer than those found in sand but not as fine as those that make up clays. These finer particles cannot be seen by eye, but there are laboratory methods of determining their size so that it is possible to lay down certain limits for the accurate description of soil types.
Sand particles smaller than No.
Silts particles smaller than 0.02 mm and larger than 0.002 mm in diameter Clays particles smaller than 0.002 mm in diameter. These sizes relate to soils consisting of aggregations of particles of approximately the same size. Glacial till is perhaps the best example of a soil mixture since it usually consists of particles ranging all the way from boulders to clay. If one looks carefully at a sample of any such soil mixture, it is not hard to appreciate that between the individual soil particles there are voids. In the case of a dry soil, the voids are filled with air.