Internal walls are occasionally built of stone or concrete, but more frequently of brick, the thickness as a rule depending mainly on the amount of money available. Brick walls only A inches thick are often used, but certainly a greater thickness is to be desired. Thick walls have the advantages of strength, increased fire-resistance, and of deadening sound.

The word ••partition" is not easy to define. Formerly it was applied exclusively to structures of wood, such as the ordinary boarded partition, and the framework of wood posts, etc, known as "studding"; but latterly it has been applied to various special kinds of brick and concrete blocks, devised for the purpose of providing light but strong and fire-resisting walls in the upper stories of buildings.

Studdings consists of upright wood posts resting on sills secured to the floor-joists or floor-boards, or - in the case of lofty and heavy partitions - to beams provided for the purpose. The studs or posts (for ordinary partitions not exceeding 10 feet high) may be anything from 4 indies by 3 inches to 8 inches by 1 inches, fixed about one foot from centre to centre, and braced across to give rigidity. The partition is usually covered on both sides with laths and plaster, like an ordinary ceiling. There are grave objections to these lath-and-plaster partitions: they are inflammable, and easily damaged; they harbour vermin, and transmit sound with great facility. In these days of steel joists, it is an easy matter to substitute a brick wall in almost every case. Certainly studding should not be tolerated between a W.C. or bathroom and a bedroom or sitting-room, or between two bedrooms.

Formerly brick-nogged partitions were much in vogue, i.e. partitions with the spaces between the timbers filled with bricks, but they are less frequently I nowadays, as it is simpler, cheaper, and better to dispense with the wood framing and to provide a steel joist to carry the brickwork.

Where exceptionally light fire-resisting partitions are required, special contrivances may be adopted instead of woodwork; as, for example, pumice bricks, hollow bricks, hollow concrete blocks, thin concrete walls (the concrete composed of Portland cement and breeze). One of these special kinds of partition is shown in Fig. 64. It is constructed of fire-resisting blocks 5 feet 5 inches long, 10 inches high, and 2 inches thick, each block having five small holes running throughout its length to reduce the weight. The blocks are secured to floors, walls, and ceilings by means of U-shaped metal clamps, and to each other by Z-shaped clamps "forced into slits cut by a saw in the adjoining edges of the blocks, one half of the clamp entering one block, whilst the other half enters the adjoining block". The partition is afterwards plastered on both sides, the plaster making the total thickness of the completed partition about 3 inches. The weight of the partition is about one-fourth the weight of a 4-inch brick wall. Several other partitions of a light but fire-resisting character are also now used, such as Picking's, Shepwood's, and Wright's. Sometimes partitions are formed of two layers of metal lathing attached to the two sides of a very light iron or steel framework, and covered on both sides with good plaster; the plaster forced through the meshes of the lathing renders the partition practically solid. The Expanded Metal Company dispenses with one layer of lathing by erecting a series of tightly-drawn vertical wires and inter-weaviui the sheets of expanded metal horizontally between them; thus, the first sheet will pass in front of the first wire, behind the second, in front of the third, and so on, while the sheet above it will pass behind the first wire, and in front of the second.

Internal Walls And Partitions 10084Fig. 64   Hygienic Block Partition.

Fig. 64 -" Hygienic "Block Partition.