PARTITIONS The studding used in partition walls is usually of 2X4-inch stuff, although 2X 3-inch studding may sometimes be used to advantage if the partition does not support any floor joists.
Furring Walls. The partition walls are made 4 inches wide, the same as in the outer walls, except in the case of so-called "furring" partitions. These are built around chimney breasts and serve to conceal the brickwork and furnish a surface for plastering. They are formed by placing the studding flatwise, in order to make a thin wall; and as it is usually specified that no woodwork shall come within 1 inch of any chimney, a 1-inch space is left between the brickwork and the furring wall. It is possible to apply the plaster directly to the brickwork, and this is sometimes done, but there is always danger that cracks will appear in the plastering at the corner mil, Fig. 120, between the chimney breasts and the outside wall. This cracking is due to the unequal settlement of the brickwork and the woodwork since the plastering goes with the wall to which it is applied. The method of constructing a furring wall is shown in plan in Fig. 121. AA are the furring studs, B is the plastering, and CC the studding in the outside wall. The arrangement without the furring wall is shown in plan in Fig. 120. If there are any open ings in the furring wall, such as fireplaces, or "thimbles" for stove pipes, it is necessary to frame around them in the same way as was explained for door and window openings in the outside walls. See Fig. 122. A A are furring studs, BB are pieces forming the top and bottom of the opening.
If the outside walls of • the building are of brick or stone, a wood "furring" wall is usually built just inside of the outer wall; this furnishes a surface for plastering and for nailing the inside finish. The stud ding for these walls is 2 X 4 inches or 2 X 3 inches or 1 X2 inches set close up against the masonry wall and preferably spiked to it. Sec Fig. 123. Spikes are usually driven directly into the mortar between the bricks or stones of the wall, but sometimes wood blocks or wedges are inserted in the wall to afford a nailing surface.
Wherever a wood partition wall meets a masonry exterior wall at an angle, the last stud of the partition wall should be securely spiked in the masonry wall, to prevent cracks in the plastering.
Cap and Sole. All partition walls are finished at the top and bottom by horizontal pieces, called, respectively, the "cap" and the "sole." The sole rests directly on the rough flooring whenever there is no partition under the one which is being built; but if there is a partition in the story below, the cap of the lower partition is used as the sole for the one above. The sole is made wider than the stud ing forming the partition wall, so that it projects somewhat on each side and gives a nailing surface for the plasterer's grounds and for the inside finish. It is usually made about 2 inches thick and 51 inches wide, when the partition is composed of 4-inch studding, and this leaves a nailing surface of 4 of an inch on each side. The sole is shown at B in Fig. 124. The cap is usually made the same width as the studding, and 2 inches thick, so that a 2 x 4-inch piece may be used in most cases; but if the partition is called upon to support the floor beams of the floor above, the cap may have to be made 3 or even 4 inches thick, and some architects favor the use of hard wood such as Georgia pine for the partition caps. The cap is shown at A, Fig. 125.
Bridging. In order to stiffen the partitions, short pieces of studding are cut in between the regular studding in such a way as to connect each piece with the pieces on each side of it. Thus, if one piece of studding is for any reason excessively loaded, it will not have to carry the whole load alone but will be assisted by the other pieces. This operation is called "bridging," and there are two kinds, which may be called "horizontal bridging" and "diagonal bridging." The horizontal bridging consists of pieces set in horizontally between the vertical studding to form a continuous horizontal line across the wall, every other piece, however, being a little above or below the next piece as shown in Fig. 126. The pieces are 2 inches thick and the full width of the studding; and in addition to strengthening the wall, they prevent fire or vermin from passing through, and also may be utilized as a nailing surface for any inside finish such as wainscoting or chair rails.