In some cases partitions are carried up one above the other through two or three stories. Such partitions may be so arranged as to assist one another. Fig. 315 gives an outline of a partition extending through two stories, in which the door studs of the upper partition are supported by the queen posts of the truss of the one below.
In this particular example no straps are used, the tightening up of the truss being effected by the bolts shown in dotted lines.
1 Modified from an example in Newland's Carpenter's and Joiner's Assistant.
Fig. 314. Details of Partition.
Fig. 315. Partition through two Floors.
Iron straps are also used as in roofs, but in partitions they are often unnecessary and have the great disadvantage of interfering with the key of the plastering, unless trouble is taken as described (p. 148) to prevent this.
"Weights and Scantlings of Partitions.
Pounds per square.
The weight of a square of partitioning may be taken at from
1480 to 2000.
The weight of a square of single-joisted flooring, without counter-flooring ....
1260 to 2000.
The weight of a square of framed flooring, with counter-
2500 to 4000.
4 inches by 3 inches for bearing not exceeding 20 feet.
If the partition has to sustain the weight of a floor or roof, the sizes of the timbers must be increased to meet the additional strain that will come upon them.
In very common work, or when there is not room for a thicker partition, the brick nogging is of brick on edge, and therefore only 3 inches thick.
In a brick-nogged partition the quarterings should be at a distance apart equal to some multiple of the length of the bricks used, so that an exact number of bricks may fit in between them without the expense of cutting.
Horizontal "nogging pieces" about 1 inch to 3 inches thick should be fitted in between them in every third or fourth course of the brickwork. They are frequently placed at much deeper intervals.
Since the introduction of Portland cement, half-brick walls have greatly superseded brick-nogged partitions wherever partitions occur one above the other.