The finish on each side of a door opening and also about the window openings is variously designated by the terms trim, casings or architraves. [The term "casing" appears to be the most widely used, and has been adopted by the author. The term " architrave" is frequently used to designate the piece inside of the "back band."]
Various methods of finishing the door openings are also employed. The style of finish shown at A, Fig. 234, is termed "block" or "pilaster " finish ; square blocks being placed in the upper corners and the casings butting against them. The blocks are usually ornamented by turned rosettes or by carving. In this style of£ finish any shrinkage in the casings does not show, as they will not shrink lengthways, and, the block being made 1/8 inch thicker than the casings, any shrinkage in the block will hardly be perceptible. The blocks are also generally made ¼ inch wider than the casings.
The style of finish shown at B is known as "mitred" finish. When mitred finish is used, especially if it is to be varnished, it is absolutely necessary that the wood be thoroughly dry, as any shrinkage in the casings will cause the mitre joints to open very perceptibly. In painted work this can be remedied by putty and another coat of paint, but in varnished work the crack cannot be hidden.
The casings may be composed of one or more members as desired.
Fig. 236 but if they are to be more than 13/16 inch thick it is better to make them of two or even more members, as shown at E and F, Fig. 234. There is less chance for shrinkage where two pieces are used and it requires less stock.
In Section E the piece b is called the " back band," and it is rebated so as to fit over the casing or " architrave " about $ of an inch. In varnished work the trim should be built up in this way rather than by simply planting a thin moulding over the casing, as it shows no joint at the back of the casing, and the rebated joint between the two members permits of a slight shrinkage without showing.
At Cis shown a combination of the block and mitre finish, which is very suitable for ordinary hard wood work. A section of the finish is shown at F. The casing is made \ of an inch thick by from 4 to
4 ½ inches wide, and has blocks in the upper corners of the same thickness as the casing. The back band extends around the block and is mitred at the corner. This does away with the mitre joint in the casing and does not look as heavy as the block finish.
Fig. 237 shows another method of constructing a door or window trim. In this case a flat moulding is planted or glued on to the casing and another moulding glued to the outer edge to cover the joint. At the corner the moulded portion of the casing is mitred, but the plain part has a straight joint as shown at a. Such a joint will open less, with the same amount of shrinkage, than a mitre joint.
In putting up the finish the architrave or casing should be kept about ¼ of an inch back from the edge of the frame, as shown in the sections.
The design or profile of the door or window finish may be varied to an almost infinite degree, and no especial attempt has been made in these drawings to suggest mouldings, but merely to show the general methods of using them. Pilaster casings with corner blocks should as a rule have both edges alike. In Fig. 238 a few sections of casings that have been used by various architects are given as a suggestion to the draughtsman. A few designs for cornices or "caps" above the doors and windows are also given. At A is shown a simple cap, worked from a single 7/8-inch board, which makes a neat and inexpensive finish. When the picture-moulding comes just above the top of the door or window casing, it will look much neater if the head casing is made wider than the others, so that the picture moulding may break over it, as at C.
Fig. 239 shows three different arrangements of pilaster casings with cornice. The detail at B is from Colonial work. The detail at C makes a. neat and not very expensive finish, and one that has no mitre joints. The egg and dart mouldings may be machine work.
Fig. 240 shows still another design for a pilaster treatment, after the German style. For very elaborate finish, and especially in public buildings, the pilasters are often terminated by inverted consoles which support the cornice.
In Fig. 241 is shown a mitred casing with the back band broken at the top, an arrangement quite frequently seen. Fig. 242 shows a heavy pilaster finish with a highly ornamented cornice. These last two examples are from Colonial mansions.
When a heavy pilaster is placed each side of the door or window openings it is generally better to set the pilaster 3 or 4 inches back from the edge of the jamb, with a narrow architrave around the opening, as in Fig. 242.
When the door and window openings are finished with a cornice the appearance of the room and of the wall decoration will be enhanced if the cornice is on the same level above all of the openings; as the window heads are usually higher above the floor than the door heads, a little different arrangement of the finish is required to bring the cornices to the same level.
Fig. 243 shows a very simple arrangement that the author has used for overcoming this difficulty, with good effect. If the difference in the height of the doors and windows is more than 9 inches, however, it will be necessary to either place a transom over the doors or an ornamental panel, or else let the cornices be at different levels
When the room is wainscoted the draughtsman should not forget to consider how the cap and base is to stop against the door finish. Usually the trim is finished with a wide backhand, as in Figs. 236 and 271, but where the cap of the wainscoting is quite heavy, as is often the case in public buildings, it is necessary to place a narrow pilaster or bracket just beside the door trim to stop the mouldings of the wainscoting, as shown in Fig. 275.