WALL Let us next consider the framing of the walls of a wood or frame building. In this work there are two distinct methods of procedure, known, respectively, as "braced framing" and "balloon framing," of which the first is the older and the stronger method, while the second is a modern development and claims to be more logical and at the same time more ical than the other. Balloon ing has come into use only since about the year 1850, and it is still regarded with disfavor by many architects, especially by those in the eastern states. Figs. 90 and 91 show the framing of one end of a small building by each of the two methods, the braced framing in Fig. 90 and the balloon framing in Fig. 91.
Braced Frame. In a full-brac ed frame all the pieces should be fastened together with mortise and-tenon joints, but this re quirement is much modified in common practice, a so-called "combination" frame being used in which some pieces are mortised together and others are fastened by means of spikes only. A framework is constructed consisting in each wall of the two "corner posts" AA, Fig. 90, the "sill" B, and the "plate" C, together with a horizontal "girt" D at each story to support the floors, and a diagonal "brace" E at each corner, which, by keeping the corner square, prevents the frame from being distorted.
Balloon Frame. In a balloon frame there are no braces or girts, and the intermediate studs FFF, Fig. 91, are carried straight up from the sill H to the plate K, with a light horizontal piece called a "ribbon" or "ledger board," set into them at each floor level to support the floor joists. This frame depends mainly upon the board ing for its stiffness, but sometimes light diagonal braces are set into the studs at each corner to prevent distortion. The methods by which all these pieces are framed together will be explained in detail under the proper headings.
Sill. The sill is the first part of the frame to be set in place. It rests directly on the underpinning and extends all around the building, being jointed at the corners and spliced where neces sary; and since it is subject to much cutting and may be called upon to span quite considerable openings (for cellar windows, etc.) in the underpinning, it must be of a good size. Usually it is made
of 6 X 6-inch square timber, but in good work it should be 6 X 8 inches and nothing lighter than 6 X 6 inches should be used ex cept for piazza sills. For piazza sills a 4 X 6-inch timber may be used. The material is generally spruce, although sometimes it is Norway pine or native pine (depending upon the locality).
The sill should be placed on the wall far enough back from the outside face to allow for the water table, which is a part of the outside finish, which will be described later; and 1 inch should be regarded as the minimum distance between the outside face of the sill and the outside face of the underpinning, Fig. 92. A bed of mortar A, preferably of cement mortar, should be prepared on the top of the underpinning, in which the sill C should rest; and the under side of the sill should be painted with one or two coats of linseed oil to prevent it from absorbing moisture from the masonry. In many cases, at intervals of from 8 to 10 feet, long bolts B are set into the masonry. These bolts extend up through holes bored in the sill to receive them and are fastened at the top of the sill by a washer and a nut screwed down tight. They fasten the sill, and consequently the whole frame securely to the underpinning, and should always be provided in the case of light frames in exposed positions.
The beams or "joists" D, which form the framework of the first floor, are supported at one or both ends by the sill and may be fastened to it in any one of several different ways. The ideal method is to nang the joist in a patent iron hanger fastened to the sill, as shown in Fig. 93, where A is the sill, B the joist, and C the hanger. In this case neither the sill nor the joist need be weakened by cutting, but it is too expensive a method for ordinary work, although the saving in labor largely offsets the cost of the hanger. The usual method is to cut a mortise in the sill to receive a tenon cut in the end of the joist, as shown at A in Fig. 94. The mortises are cut in the inside upper corner of the sill. They are about 4 inches deep and cut 2 inches into the width of the sill and are fixed in position by the spacing of the joists.