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.
251. It is evident that, if buildings are to be fireproof, as little wood as possible should enter into their construction; hence, only expanded metal or wire lath should be used to hold the plaster, unless the floors and partitions are of tile, in which case very little lathing is required. The plaster should be either one of the hard kinds or machine-mixed mortar, preferably the first. Where a hard plaster is to be applied to lathing, the latter should have a close mesh, and should be either galvanized or painted.
Girder Protection. Cornices to protect and conceal girders are often formed by constructing a frame of light iron strips and covering it with wire lath, to which the plastering is applied. This method of casing a girder is represented in Fig. 110, which shows a stiff framework of light iron bars a, bent to form the desired outline, and attached to the girder by clamps b and c. To this frame is fastened the wire cloth d, upon which the plaster c is laid.
Column Protection. Fig. 111 shows the method of casing a column, using a similar framework, securely fastened to the column. At (a) and (b) are indicated the methods of forming round and square columns; the wire cloth a is wrapped around and fastened to light frames b, spaced at proper distances, and firmly clamped, as at c, to the column d.
112 represents a method of constructing thin partitions, using very light T bars, or channels, and wire lathing to support the plaster. At a is shown one of the 3/4-inch channels, which are spaced from 12 to 16 inches apart and firmly fastened to both floor and ceiling; at b is shown the wire cloth, stretched and laced to the channel studs; at c, the plastering, which should be the best kind of work, as upon it depends largely the stiffness of the partition; and at d, a2" x 3" piece of wood, to which the baseboard e is nailed.
Another form of thin wire partition has a 1/4-inch rod woven into the cloth at distances of about 8 inches. The lathing is tightly stretched over the studs, with the rods crossing the latter at right angles, and well laced where they cross.
When moldings are required, strips of wood may be laced to the lathing at the proper height. The plaster when put on holds the strips firmly in place, and the picture mold may be screwed to it. If a close-mesh lathing is used, the moldings may be fastened by screws directly to the wire cloth.