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.
40. The proportions of the panels, and the details of the design of the panels and moldings of doors, are subject to great variation. The lock-rail, however, should always be in a position not too low for one to be able to reach the lock without stooping, nor too high for a person to grasp the knob without reaching. The standard height to the center of the knob of the lock has been fixed at 3 feet from the floor. The lock should be mortised into the stile between the tenons of the lock-rail, or immediately above them, in order not to destroy these tenons when the lock is inserted. A preferable method is to put in a lock-panel from 6 inches to 7 inches wide in place of the lock-rail; this is accomplished by practically cutting the lock-rail in two in the width and inserting a panel between the sections, as shown in Figs. 21 and 22.
41. The moldings around the panels of doors may be a simple ogee, worked on the edges of the stiles and rails, or they may be inserted in the angle between the edge of the stile or rail and the panel, as shown in Fig. 19, care being taken to see that the nails pass into the edges of the framing (and not into the panels), as suggested in the Figure.
42. In some foreign countries, and in certain localities of America, the stiles and rails of panel work are put together with dowels, as shown in Fig. 20. These dowels vary from 3/8 inch to 1 inch in diameter, according to the thickness of the wood to be united, but in any case they are considerably thicker than a mortise would be in the same material. Along the edge of each dowel, a V-shaped groove is cut, as shown at a, to allow the air and surplus glue to escape when the parts are driven together.
43. Sliding doors differ from ordinary swing doors chiefly in the method of hanging them, and, as the strain of their parts is reduced or increased with the different methods, a corresponding alteration of the details of their framing is necessary. Fig. 21 (a) shows one of a pair of sliding doors, which is intended to be hung from the top, as the stile is not then subjected to as great a strain as when the door is hung on the side. Where a sliding door is hung with the patent stile hanger, which brings the entire weight upon the stile, particular attention must be given the mortises and tenons in the hanging stile to insure their perfect fit, as the slightest loosening would cause a sag in the door, which would prevent it from running smoothly.
In the plan of this door, shown at (b), the meeting rails of both doors are shown, and, as will be seen, the edges of the rail are worked to fit together in a shallow tongued-and-grooved joint. This preserves the alinement of the doors when closed, and tends to prevent the appearance of a slit, or crack, between them, as would be the case if they simply butted together.
In opening, the doors slide into a pocket built in the partition, as shown at d, the dotted lines c showing the position of the door when it is in the pocket. This pocket is framed and finished in the same manner as a simple studded partition, except that the studs are set in two rows with a space between them, at d, about 1 1/2 inches to 2 inches wider than the door is thick. The jambs of the door opening are then finished with a molded trim, which is let into the jamb, as shown at f", and is allowed to project over the end of the pocket to within 1/4 inch of the door. A stop is provided within the pocket d, to prevent the door from sliding too far into the opening. The hardware on the meeting stiles of the door must be sunk flush with the face of the stile, so that it will not prevent the door from sliding clearly into the pocket. Numerous sliding-door locks and catches are provided by the hardware dealers, made specially for this style of door.
44. Folding doors consist of a pair of single doors hinged on opposite sides of the opening, and provided with a stop-bead or rabbeted stile, so that they will close together in a tight joint at the middle of the opening. Fig. 22 shows a plan (a) and an elevation (b) of a pair of folding doors which are arranged to meet the requirements of the outside vestibule-entrance doors, or storm doors as they are sometimes termed, of a frame dwelling. When this form of door is used as an inside vestibule door or a direct-entrance door, the panels b, as shown at o in the section B", taken on the line B B' of the elevation, are usually of glass, but in the former case the transom only may be glazed, to admit light to the vestibule when both doors are closed. The sectional plan A" of the door is taken on the line A A', and shows the two lower panels at p. The framing of the stiles and rails of folding doors is precisely the same as for single swing doors, but the meeting rails must be rabbeted, as shown at c, so as to provide a stop against which the more frequently used door may close.
This rabbeted stop must be beveled off slightly on the inside, to give proper clearance to the outside angle of the door when it is opened. The amount of bevel necessary in order to accomplish this clearance is found by striking a circular are j k with a radius kl equal to the diagonal distance from the corner k of the door to be cleared to the center of the butt pin /, and with a center at the latter point.