Upon completing this section, you should be able to describe the procedures for laying out and installing interior doofram es, doors, and the hardware used.

Rough openings for interior doors are usually framed to be 3 inches higher than the door height and 2 1/2 inches wider than the door width. This provides for the frame and its plumbing and leveling in the opening. Interior doorframes are made up of two side jambs, a head jamb, and the stop moldings upon which the door closes. The most common of these jambs is the one-piece type (shown in fig. 6-23, view A). Jambs can be obtained in standard 5 1/4 inch widths for plaster walls and 4 5/8 inch widths for walls with 1/2-inch drywall finish. The two- and three-piece adjustable jambs (views B and C) are also standard types. Their principal advantage is in being adaptable to a variety of wall thicknesses.

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Figure 6-23.—Interior door framing parts.

Some manufacturers produce interior doorframes with the doors fitted and prehung, ready for installing. Installation of the casing completes the job. When used with two- or three-piece jambs, casings can even be installed at the factory.

Common minimum widths for single interior doors are as follows: bedrooms and other habitable rooms, 2 feet 6 inches; bathrooms, 2 feet 4 inches; and small closets and linen closets, 2 feet. These sizes vary a great deal, and sliding doors, folding door units, and similar types are often used for wardrobes and may be 6 feet or more in width. However, in most cases, the jamb stop and casing parts are used in some manner to frame and finish the opening.


Casing is the edge trim around interior door openings and is also used to finish the room side of windows and exterior doorframes. Casing usually varies in widths from 2 1/4 to 3 1/2 inches, depending on the style. Casing is available in thicknesses from 1/2 to 3/4 inch, although 11/1 6 inch is standard in many of the narrow-line patterns. A common casing pattern is shown in figure 6-23, view D.

The two general types of interior doors are the flush and the panel. Flush interior doors usually have a hollow core of light framework and are faced with thin plywood or hardboard (shown in fig. 6-24). Plywood-faced flush doors (fig. 6-25, view A) maybe obtained in gum, birch, oak mahogany, and several other wood species, most of which are suitable for natural finish. Nonselected grades are usually painted as hardboard-faced doors.

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Figure 6-24.—Hollow-core construction of flushed doors.

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Figure 6-25.-Interior door types.

The panel door consists of solid stiles (vertical side members), rails (cross pieces), and panels of various types. The five-cross panel and the colonial-type panel doors are perhaps the most common of this style (fig. 6-25, views B and C). The louvered door (view D) is also popular and is commonly used for closets because it provides some ventilation. Large openings for wardrobes are finished with sliding or folding doors, or with flush or louvered doors (view E). Such doors are usually 1 1/8 inches thick.

Hinged doors should open or swing in the direction of natural entry, against a blank wall whenever possible. They should not be obstructed by other swinging doors. Doors should never be hinged to swing into a hallway.


When the frame and doors are not assembled and prefitted, the side jambs should be fabricated by nailing through the dado into the head jamb with three 7d or 8d coated nails (fig. 6-23 view A). The assembled frames are then fastened in the rough openings by shingle wedges used between the side jamb and the stud (fig. 6-26, view A). One jamb is plumbed and leveled using four or five sets of shingle wedges for the height of the frame. Two 8d finishing nails should be used at each wedged area one driven so that the doorstop covers it. The opposite side jamb is then fastened in place with shingle wedges and finishing nails, using the first jamb as a guide in keeping a uniform width.

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Figure 6-26.—Doorframe and trim.

Casings should be nailed to both the jamb and the framing members. You should allow about a 3/16-inch edge distance from the face of the jamb. Use 6d or 7d finish or casing nails, depending on the thickness of the casing. To nail into the stud, use 4d or 5d finish nails or 1 1/2-inch brads to fasten the timer edge of the casing to the jamb. For hardwood casing, it is advisable to predrill to prevent splitting. Nails in the casing should be located in pairs and spaced about 16 inches apart along the full height of the opening at the head jamb.

Casing with any form of molded shape must have a mitered joint at the comers (fig. 6-26, view B). When casing is square-edged, a butt joint maybe made at the junction of the side and head casing (fig. 6-26, view C), If the moisture content of the casing material is high, a mitered joint may open slightly at the outer edge as the material dries. This can be minimized by using a small glued spline at the corner of the mitered joint. Actually, use of a spline joint under any moisture condition is considered good practice, and some prefitted jamb, door, and casing units are provided with splined joints. Nailing into the joint after drilling helps retain a close fit.

The door opening is now complete except for fitting and securing the hardware and nailing the stops in proper position. Interior doors are normally hung with two 3 1/2-by 3 1/2-inch loose-pin butt hinges. The door is fitted into the opening with the clearances shown in igure 6-27. The clearance and location of hinges, lockset, and doorknob may vary somewhat, but they are generally accepted by craftsmen and conform to most millwork standards. The edge of the lock stile should be beveled slightly to permit the door to clear the jamb when swung open. If the door is to swing across heavy carpeting, the bottom clearance may need to be slightly more.

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Figure 6-27.—Door clearances.

Some manufacturers supply prefitted doorjambs and doors with the hinge slots routed and ready for installation. A similar door buck (jamb) of sheet metal with formed stops and casing is also available.


Hardware for doors is available in a number of finishes, with brass, bronze, and nickel being the most common. Door sets are usually classified as entry lock for interior doors; bathroom set (inside lock control with safety slot for opening from the outside); bedroom lock (keyed lock); and passage set (without lock).

As mentioned earlier, doors should be hinged so that they open in the direction of natural entry. ‘hey should also swing against a blank wall whenever possible and never into a hallway. The door swing directions and sizes are usually shown on the working drawings. The "hand of the door" (fig. 6-28) is the expression used to describe the direction in which a door is to swing (normal or reverse) and the side from which it is to hang (left or right).

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Figure 6-28.—"Hands" of doors.

When ordering hardware for a door, be sure to specify whether it is a left-hand door, a right-hand door, a left-hand reverse door, or a right-hand reverse door.


You should use three hinges for hanging 1 3/4-inch exterior doors and two hinges for the lighter interior doors. The difference in exposure on the opposite sides of exterior doors causes a tendency to warp during the winter. Three hinges reduce this tendency. Three hinges are also useful on doors that lead to unheated attics and for wider and heavier doors that may be used within the structure. If a third hinge is required center it between the top and bottom hinges.

Loose-pin butt hinges should be used and must be of the proper size for the door they support. For 1 3/4-inch-thick doors, use 4- by 4-inch butts; for 1 3/8-inch doors, you should use 3 1/2- by 3 1/2-inch butts. After the door is fitted to the tied opening with the proper clearances, hinge halves are fitted to the door. They are routed into the door edge with about a 3/16-inch back distance (fig. 6-29, view A). One hinge half should be set flush with the surface and must be fastened square with the edge of the door. Screws are included with each pair of hinges.

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Figure 6-29.—Installation of door hardware.

When fitting doors, you should temporarily nail the stop in place; this stop will be nailed in permanently when the door has been hung. Stops for doors in single-piece jambs are generally 7/16 inch thick and may be 3/4 inch to 2 1/4 inches wide. They are installed with a mitered joint at the junction of the side and head jambs. A 45 bevel cut at the bottom of the stop, about 1 to 1 1/2 inches above the finish floor, eliminates a dirt pocket and makes cleaning or refinishing of the floor easier (fig. 6-26, view A).

The lock should be installed so that the doorknob is 36 to 38 inches above the floor line. Most sets come with paper templates, marking the location of the lock and size of the holes to be drilled. Be sure to read the manufacturer’s installation instructions carefully. Recheck your layout measurements before you drill any holes.

The door should now be placed in the opening and blocked up at the bottom for proper clearance. The jamb should be marked at the hinge locations, and the remaining hinge half routed and fastened in place. The door should then be positioned in the opening and the pins slipped in place. If you have installed the hinges correctly and the jambs are plumb, the door should swing freely.


The types of door locks differ with regard to installation, cost, and the amount of labor required to set them. Some types, such as mortise locks, combination dead bolts, and latch locksets, require drilling of the edge and face of the door and then routing of the edge to accommodate the lockset and faceplate (fig, 6-29, view B). A bored lockset (view C) is easy to install since it requires only one hole drilled in the edge and one in the face of the door. Boring jigs and faceplate markers are available to ensure accurate installation.

The parts of an ordinary cylinder lock for a door are shown in figure 6-30. The procedure for installing a lock of this type is as follows:

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Figure 6-30.—Parts of a cylinder lock.

  1. Open the door to a convenient working position and check it in place with wedges under the bottom near the outer edge.
  2. Measure up 36 inches from the floor (the usual knob height), and square a line across the face and edge of the lock stile.
  3. Place the template, which is usually supplied with a cylinder lock, on the face of the door at the proper height and alignment with layout lines and mark the centers of the holes to be drilled. (A typical template is shown in fig. 6-31.)

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Figure 6-31.—Drill template for locksets.

  1. Drill the holes through the face of the door and then the hole through the edge to receive the latch bolt. It should be slightly deeper than the length of the bolt.
  2. Cut again for the latch-bolt mounting plate, and install the latch unit.
  3. Install the interior and exterior knobs.
  4. Find the position of the strike plate and install it in the jamb.

Strike Plates

The strike plate, which is routed into the doorjamb, holds the door in place by contact with the latch. To install, mark the location of the latch on the doorjamb and locate the position of the strike plate by outlining it. Rout out the marked outline with a chisel and also rout for the latch (fig. 6-32, view A). The strike plate should be flush with or slightly below the face of the doorjamb. When the door is latched, its face should be flush with the edge of the jamb.

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Figure 6-32.—Door details.


The stops that have been temporarily set during the fitting of the door and the hardware may now be nailed in permanently. You should use finish nails or brads, 1 1/2 inches long. The stop at the lock side (fig. 6-32, view B) should be nailed first, setting it tight against the door face when the door is latched. Space the nails in pairs 16 inches apart.

The stop behind the hinge side should be nailed next, and a 1/32-inch clearance from the door face should be allowed to prevent scraping as the door is opened. The head-jamb stop should then be nailed in place. Remember that when the door and trim are painted, some of the clearance will be taken up.


The items of commercial/industial door hardware shown in figure 6-33 are usually installed in commercial or industrial buildings, not residential housing. These items are used where applicable, in new construction or in alterations or repairs of existing facilities. Most of these items are made for use in or on metal doors, but some items are made for wood doors. Follow the manufacturer’s installation instructions. Recommended door hardware locations for standard steel doors are shown in figure 6-34. Standard 7-foot doors are usually used in commercial construction.

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Figure 6-33.—Commercial hardware.

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Figure 6-34.-Location of hardware for steel doors.