This section is from the book "A Treatise On Architecture And Building Construction Vol2: Masonry. Carpentry. Joinery", by The Colliery Engineer Co. Also available from Amazon: A Treatise On Architecture And Building Construction.
116. Partitions are constructed of pieces of timber from 2 in. X 4 in. to 3 in. X 6 in. in section, called studs, which are set vertically, with the depth of the stud in the direction of the thickness of the partition, and are spaced 12 inches or 16 inches on centers, in order to accommodate the 4-foot lengths of lath which they are to carry. Any difference that may be required in spacing should be made at one end of the room, or, where the irregularity of spacing is caused by the insertion of a door or window, the difference should be made entirely on one side of the opening. Every spacing of studs which is a variation of the above will cause the laths to project past, or fall short of, the desired nailing point for their ends, necessitating in either case the cutting of the lath at the center of the nearest stud, thereby causing an expenditure of time and a waste of material.
117. Where partitions are required in a direction across the floorbeams, as shown in Fig. 35, a sill a is first laid on the beams and perpendicularly over it, and on the under side of the ceiling beams is nailed a cap, shown at b, Fig. 36; between this sill and cap the studs are set and securely toe-nailed through each end.
118. In Fig. 37 is shown a method of securing a firm internal angle at the corner of a building. a is the corner post of a building resting upon the sill s, and b', b, b are the studs of the outside wall. The corner post in this case is made with a 4"x6" piece a, and a 2"x4" stud b' spiked to it flush with the outside. This arrangement leaves the two surfaces c and c, to which the ends of the lath of each wall may be securely nailed.
119. In Fig. 38 is shown a method of forming the interior angles where partitions are placed at right angles to each other; g, g' are two studs, which may also be in the outside wall of a building, and h, h are the studs of an interior partition. At f on the partition, or wall, is a piece of plank 1 inch thick and 2 inches wider than the stud h to which it is nailed, and extending from the sill a to the top of the partition, thus affording a surface on each partition where the lath ends may be nailed, as at d and e. A strip may with advantage be nailed on top of the sill, to which the plank f can be nailed.
120. When the partition of an upper story comes vertically over one in the story below, the studs of the upper one should be set upon the cap of the one below, as shown at c', Fig. 36, and not upon the beams, as in Fig. 35.
This reduces the effects caused by the shrinkage of the timbers, which is bound to occur as the building dries out, and the fewer transverse thicknesses we have as supporting members to partitions, etc., the less will be the shrinkage and ultimate settlement of the whole house.
When a partition runs parallel with the beams it should stand on a beam framed in especially to receive it, or it should rest on the cap of the partition below, if such a partition exists.
121. All important partitions should be well supported at their foundations, either by a brick wall or by a girder carried upon brick piers or wooden posts, with masonry footings. This girder should be very little deeper than the sill of the house, or, when extra depth is demanded by the degree of strength required, the ends of the beams may be notched over the edge of the girder in somewhat the same manner as the floorbeams are notched over the sill in Fig. 30. In this way the amount of shrinkable material between the top of the post and the bottom of the partition studs may be reduced to very nearly the same as it would be in the sill under the outside walls; or, if the girder cannot be notched sufficiently to effect this, the house sill may be made somewhat thicker, or the floorbeams must be set with their interior ends slightly raised, so that subsequent shrinkage of the girder will render them level. It is shrinkage of material that causes new houses to settle, and if the settlement is uniform, no harm results from it, but irregular settlement causes uneven floors, cracked plaster, and doors and windows that refuse to open readily or close tightly.
Good, sound, well dried material, therefore, should always be used, when such is obtainable, and all unsound, curved, knotty, or shaky timber should be rejected as unfit for any purpose except firewood.
122. Lathing is applied to the partitions as soon after the studs are in place as is convenient. Where pipes or wires are to be carried within the walls, it is sometimes necessary to delay at least a portion of the lathing until they are in place; or, when the" exact location of these interior lines is determined upon, the lath may be left off one side of the partition until the wiring or pipe lines have been inserted.
Laths consist of strips of soft wood, generally 1 1/2 inches wide, 1/4 inch thick, and 48 inches long; they are laid horizontally on the partitions, nailed to each stud, and maintained, as nearly as possible, at a uniform distance apart - usually from 1/4 to 3/8 inch, as shown at g, in Fig. 43.
To guard against unsightly cracks in the plaster at the angles of the rooms, suitable nailing strips, as d and e, Fig. 38, or double studs, as a and b', Fig. 37, must always be provided; and under no circumstances must the lath be permitted to extend across from one stud to another behind the end of a partition, as from g to g', Fig. 38.