[Sidenote: Wood]
[Sidenote: Hollow Tile]
[Sidenote: Metal]
The inside of all exterior brick walls should be furred, except
in climatic conditions where it has proved unnecessary, in order
to form an air space between the brickwork and the plaster. This
furring may be of wood, hollow tile, or metal. The first, which
is ordinarily used, consists of 1" × 2" wooden strips placed
vertically on the wall and spaced 16 inches on center (Fig. 24).
The strips are either nailed to the lath which have been placed in
the joints of the brickwork by the mason, or attached by driving
the nails into the mortar joints. The carpenter, in placing the
strips, should wedge behind them where necessary to make them
plumb. The grounds and lath are placed directly on these strips.
Hollow tile furring is formed by splitting 3-inch or 4-inch "split
furring" tile, which have been scored in manufacturing for this
purpose, placing the webs against the brick wall, and anchoring
them by driving ten-penny nails into the mortar joints over every
third tile in every second course. The tile should be laid without
mortar so as not to make a solid connection which would transmit
moisture. This tile furring makes a good surface for interior
plastering. Metal furring is only used with metal lath and consists
of small steel rods or other stiffening members either placed
separately on the wall or as part of the metal lath.