A reveal is that part of an opening which returns at right angles from the front of the wall - i.e., that part which shows vertically between the necessary angle from the face line and the front of the door or window frame, as in fig. 112, fig. 113 being an illustration of a splayed reveal, and fig. 114 a splayed jamb, explaining the difference between that and a splayed reveal; the former applying to the internal and the latter to the external finish.
Whether a reveal be square or splayed, the student must always bear in mind that a closer must be used on each side of the opening in the same horizontal line in the same course as that in which the closer is placed at the main angles. For instance, fig. 115 represents a square reveal in a wall, in the heading course of English bond, where the king closers will be seen to advantage, fig. 116 being the succeeding or stretching course of the same.
It should be pointed out that the setting back of the jamb (or reveal, as it is sometimes improperly called) varies in width according to the joinery frame that it has to take, usually being 4 1/2 inches wide for sash-windows, and from 1 1/2 to 3 inches for door and solid window frames.
It will be obvious that a splayed reveal is made by the peculiar shape of special bricks called cants, as shown by the dotted lines to figures; whereas a splayed jamb is generally roughly cut, and worked according to convenience in bonding.
Figs. 117 and 118 represent succeeding courses up both window jambs, with a reveal in a 14-inch wall with a splayed jamb, English bond; and figs. 119 and 120 that in an 18-inch or 2-brick wall; fig. 121 showing the same, without the splayed jamb; the dotted lines on fig. 119 representing the other course.
The 14-inch wall, treated in flemish bond, is represented on figs. 122 and 123, and the 18-inch on figs. 124 and 125.
Below the sills the brickwork is often set back within the thickness of the wall, the jambs continuing down to floor-line to allow of window backs from window board to floor (as shown on fig. 140), making a 14-inch wall only 9 inches thick below the window sill and between the jambs. Vide fig. 126.