This section is from the book "A Treatise On Architecture And Building Construction Vol3: Stair Building, Ornamental Ironwork, Roofing, Sheet-Metal Work, Electric-Light Wiring And Bellwork", by The Colliery Engineer Co.. Also available from Amazon: A Treatise On Architecture And Building Construction.
32. There are many different kinds of columns and pilasters, and different methods of constructing them. In a general way, however, Fig. 19 illustrates common practice. This figure shows in elevation at (a), and in section at (b), a three-quarter column, such as is used on the front of a building. The column is braced by wooden blocking, composed of 1 1/2-inch or 2-inch horizontal blocks a, a which are spiked to an upright post d, and spaced at intervals of not more than 2 feet. Vertical strips b, b are nailed to the face of the blocks, and are run from the square plinth c to the top of the capital. The sheet metal which forms the column is continued clown to the plinth, and up to the block or other member over the capital, the seam on c being soldered water-tight. The back edges of the sheet are nailed to the face of the wall in the ordinary manner. The base is then put in place and soldered to the column. The capital should then be soldered to the column. This is one of the best methods of bracing sheet-metal columns.
In fireproof construction the same method is employed, except that iron is used instead of wood. Pilasters are formed and covered in the same manner as columns. In all column and pilaster construction, avoid the formation of pockets wherein water may accumulate.