Figure 5-13. - Box mounting on metal doorframe.
quick, simple method of installing a box on the doorframe. This anchor allows the box to be adjusted in all directions; that is, toward or away from the frame, the depth from the outside wall surface, and up or down as needed. The nut on the bolt shown in the figure holds the bracket to the anchor and must be loose while the anchor is installed. The anchor itself consists of a flathead bolt with a screwdriver slot and a threaded channel. The channel comes in two sizes; one for narrow doorframes not over 4 inches wide and a second for doorframes up to 7 inches wide. The anchor is set in place by inserting it in the frame channel with the flathead of the bolt toward the doorstop channel and the threaded channel under the lips of the doorframe. The anchor is locked in place by inserting a screwdriver in the slot of the bolt and turning it clockwise until tight. As you can see in the figure, the bracket is adjustable and is held in position by the tightened nut on the bolt. The box is adjustable toward or away from the doorframe and is attached to the bracket with two machine bolts and nuts.
Metal spring clips provide a quick and easy way of mounting boxes onto metal studs. The same clip will work on studs of more than one design and size, such as 1 5/8- to 3 5/8-inch C channel studs and the truss type of studs. They are designed to mount square boxes with cover plates and to permit device boxes to be flush- mounted with various thicknesses of wall surfacing. A metal spring clip is shown at the left in figure 5-14. To mount a box, tap the clip over the open edge of the box. Then tip the box so the upper prong slips behind the face of the stud, as you can see at the right in figure 5-14. Press the lower prong back with your thumb until it slips
Figure 5-14. - Box mounting on metal stud with spring clip.
behind the stud face and locks the box in place. The box can be moved easily up or down on the stud by releasing the spring tension. Boxes can also be attached to metal framing members with sheet metal screws or machine bolts and nuts.
Box Mounting Between Framing
At times, boxes must be mounted between the building or wall supports instead of directly on them. This positioning is particularly true of ceiling lights where the joists do not coincide with the spot at which the light is to be placed. In such cases, boxes must be mounted on a separate support attached to the structure. These supports may be purchased in the form of bar hangers or metal straps, or they may be constructed from metal straps or wooden strips. Figure 5-15 shows
Figure 5-15. - Box supports.Continue Reading