PARTITIONS are used to divide rooms from one another, instead of walls, to save space and expense, and they are desirable in upper stories where there are no brick or masonry walls below the divisions required between the rooms.
These may be "framed" or "common" - the former being trussed so as to carry their own weight between the walls as abutments, the latter merely resting upon a dwarf wall when intended for the ground floor - and in other cases upon walls, floors, or rolled iron joists or whatever may be immediately below them.
A quartered partition sometimes rests on the cross and party wall of the ground-floor. This is not a good arrangement, as the partition becomes cracked in consequence of its being unable to settle together with the main walls to which it is fixed.
Nor should the weight of the partition be allowed to rest on the floor below it, as it bears heavily upon the joists, cracks the ceilings below, and also settles and tears away from the ceiling above it.
A better arrangement is to suspend the partition from the floor or roof above; this prevents the cracking of the cornice above the partition.
Of course, if the weight of the partition be thrown upon either of the floors or the roof, these latter must be strengthened accordingly.
By far the best plan, however, is to make the partition self-supporting, depending only on the main walls carrying its ends, and forming, in fact, a very deep truss.
If the trussed partition be supported by two walls of very unequal height they may settle unequally, and, if so, will cause it to crack. If the walls are of equal height and well founded they will settle equally, and the partition moving with them will sustain no injury.
The framing of the truss should be so arranged as to throw the weight upon the points of support in the walls at the end of the truss.
Partitions should be made of very well-seasoned timber, and the joints carefully fitted. The whole should be allowed to stand for some time before being lathed, so that the timber may take its bearings and twisted timbers may be put right before plastering.