The illustrations show the four types in their entirety. But in order to fully understand the combination-frame, it is necessary to know what features of the braced-frame and balloon-frame are used to-day.
THE FEATURES OF THE BRACED-FRAME
WHICH HAVE SURVIVED
1. The use of the girt, because it permits the location of the second-floor windows at any point irrespective of the first floor windows. This cannot be done when a ribbon-board is used, for this requires studs which extend continuously from sill to plate, and if any windows are to be located on the second floor, they must be placed directly over those on the first floor. The ribbon-board does not act as a stop for either vermin or fire, as does the girt. However, fire-stops can be introduced in connection with the ribbon-board, if the extra expense is no hindrance.
2. The use of the sill, because it serves as a firm foundation for the outside studs and first tier of floor-joists. The balloon-frame has no sill, for the floor-joists are set directly upon the top of the foundation-wall, and the exterior studs are built on top of them.
3. The use of the corner braces, because they stiffen the frame.
TYPICAL FRAMING OF “WAR HOUSES.”
FEATURES OF THE BALLOON-FRAME
WHICH HAVE PERSISTED
1. The use of small timbers, or the standardization of the 2 by 4 for all parts except the sill, because of economy. The corner-posts are made of three 2 by 4’s, and the plate is made of two 2 by 4’s.
2. The use of the nailed joint, because of its cheapness and its greater strength. It will not rattle loose when the timber seasons, as does the mortise and tenon joint in the braced-frame.