Empirical design of columns

Columns are axially loaded vertical members used in a building structure to support floors or roofs. Columns may support one floor or many floors, depending on the configuration of the building. In most multistorey buildings, columns align from floor to floor, so that the column on the lower floor receives load directly from the column above. If the columns are not aligned, a ‘transfer girder’ is required, at least in the span in which the upper column is located. The sizing of transfer girders is discussed briefly in Chapter 5.

A significant issue in wood and steel columns is the tendency to buckle; that is, to distort in an unstable manner under large loading. This will be discussed below in Sections 4.6 and 4.7 that deal respectively with steel and wood columns. Columns in concrete and masonry are naturally stockier and have a very limited tendency to buckle. As a result, their design is controlled primarily by strength, rather than stability.