About the only difference in the construction of the window frames in a brick building from those in a wooden building, is that an additional board, B L, Figs. 97 and 98, is nailed to the back of the frame to form a box for the weights, and a moulding or strip, S, is nailed to the outside casing to make a finish with the brickwork. From the fact that a complete box is formed for the weights, frames * made as in Figs. 97 and 98 are commonly called "box frames." The pulley stile, P, and outside casing, O C, are the same as in a wooden building, and so also is the yoke. The sill of box frames, where stone sills are used, is frequently made as thin as 1 1/8 inches, and the outside edge is generally set flush with the outside of the outside casing. In cheap work, also, the rebate in the sill at R is often omitted. In all good work, however, the sill should be at least 1 3/8 inches thick, and always rebated. A thickness of 1 ¾ inches is desirable in large windows, and in some localities the wood sills are made as thick as 2 ½- inches. Some architects also show the sills projecting to the outer edge of the staff bead, S, but in the author's opinion there is no advantage in this, except that a narrower stone sill may be used, and a wide sill is more apt to " curl up " than a narrow
The piece, S, is called the "staff bead" in the Eastern States, and is there usually made of the general shape shown in Fig. 98, although a three-quarter bead is frequently used. Staff beads are generally worked out of 1 3/8 -inch stuff. In the Western States this piece is more generally termed a "brick mould," and for dwellings and ordinary brick buildings it is commonly made of the shape shown in Fig. 97, 1 1/8 inches thick and 2 inches wide. When this shape of the staff bead or brick mould is used, the piece, O C, is sometimes called the "blind stop," but its more general name is the outside casing. The section of brick mould shown in Fig. 97 is best adapted to windows that are to be fitted with outside blinds. The board, B L, is called the back lining.
The distance, X, Fig. 97, may be varied to suit the taste of the designer, but is most commonly made 2 inches. The distance, Z, is also generally made 2 inches, so that when X and Z are each 2 inches, the width of the opening will be just 8 inches more than the width of the glass for two-light windows, which is very convenient in figuring the plans and taking off the length of the sills and caps*
In an 8 or 9-inch brick wall the frame is usually set so that the inner edge of the pulley stile will just come flush with the plastering, and with 1 ¾-inch sash it is generally necessary to clip the backs of the front bricks. In thicker walls the outside casing is generally set in just the width of a brick, and sub-jambs and casings used, as shown in Fig. 98.
If a 9-inch wall is furred, there will be plenty of room for 1 ¾-inch sash without clipping the bricks, and also for a ground casing, the same as shown on the frame in Fig. 95.
The piece, J C, Fig. 98, is called the "sub-jamb," or "jamb casing," the latter term being perhaps the more common. The piece, C, is sometimes called the "sub-casing," or "inside casing," but the term "box casing" would appear to be better, as it can then not be confounded with the piece A, which is also called the casing in many localities.
The covering piece, V, is only used where the finish is to be of hard wood, or to be varnished. It has no specific name, but is generally called a veneer. The etched portions of the drawings in these figures (with the exception of the sash and wall) belong to the inside finish. The distance, Y, Fig. 98, may be varied from ½ to 3 ½ inches, but is commonly made about 2½ inches. Under the sill of all box frames a piece of joist should be built into the wall, to which the wood sill may be nailed, and to receive the ground, G, or the apron, if there is no ground.
The thickness of the various parts of a box frame are usually the same as for a skeleton frame, except that the sill is sometimes made thinner, as above noted. For large windows, and in first-class buildings, the outside casing should be 1 1/8 inches thick, and also the pulley stile.
Fig. 99 shows sections through the sill and jamb of a style of window that is quite common in some parts of Pennsylvania, where it is known as a "plank front" frame. This frame shows little reveal,
•and is frequently used without an outside lintel, the outer brick being laid on top of the frame, which, as may be noticed, is quite heavy.
This detail also shows a wood sill, which, while not as durable as a stone sill, will last for a long time if kept painted. The detail also shows paneled shutters on the outside of the window. These shutters are quite common in old work; they were usually made with flush panels on the outside, and moulded on the inside. If either shutters or blinds are used on the outside of a window in a brick wall, the hinges should be of such a shape that the shutters or blinds will open back flat against the face of the wall. Where box frames do not set into the wall, a piece of wood, about 1 ½x2 inches, should be nailed to the back lining, as shown at S, Fig. 99, to keep the frame from being pushed in or out.