Many types of exterior doors are available to provide access, protection, safety, and privacy. Wood, metal, plastic, glass, or a combination of these materials are used in the manufacture of doors. The selection of door type and material depends on the degree of protection or privacy desired, architectural compatibility, psychological effect, fire resistance, and cost.
Better quality exterior doors are of solid-core construction. The core is usually fiberglass, or the door is metal-faced with an insulated foam core. Solid-core doors are used as exterior doors because of the heavy service and the additional fireproofing. Hollow-core doors are normally used for interior applications. Wood doors are classified by design and method of construction as panel or flush doors.
A panel door, or stile-and-rail door, consists of vertical members called stiles and horizontal members called rails. The stiles and rails enclose panels of solid wood, plywood, louvers, or glass (fig. 4-16). The stiles extend the full height at each side of the door. The vertical member at the hinged side of the door is called the hinge, or hanging, stile, and the one to which the latch, lock, or push is attached is called the closing, or lock, stile. Three rails run across the full width of the door between the stiles: the top rail, the intermediate or lock rail, and the bottom rail. Additional vertical or horizontal members, called muntins, may divide the door into any number of panels. The rails, stiles, and muntins maybe assembled with either glued dowels or mortise-and-tenon joints.
Figure 4-16.-Parts of a Six-panel door.
Panel doors in which one or more panels are glass are classed as sash (glazed) doors. Fully glazed panel doors with only atop and bottom rail, without horizontal or vertical muntins, are refereed to as "casement" or "French doors." Storm doors are lightly constructed glazed doors. They are used in conjunction with exterior doors to improve weather resistance. Combination doors consist of interchangeable or hinged glass and screen panels.
Flush doors are usually made up of thin sheets of veneer over a core of wood, particle board, or fiberboard. The veneer faces act as stressed-skin panels and tend to stabilize the door against warping. The face veneer may be of ungraded hardwood suitable for a plain finish or selected hardwood suitable for a natural finish. The appearance of flush doors maybe enhanced by the application of plant-on decorative panels. Both hollow-core and solid-core doors usually have solid internal rails and stiles so that hinges and other hardware may be set in solid wood.
Two types of solid wood cores are widely used in flush-door construction (fig. 4-17). The first type, called a continuous-block, strip- or wood-stave core, consists of low-density wood blocks or strips that are glued together in adjacent vertical rows, with the end joints staggered. This is the most economical type of solid core. However, it is subject to excessive expansion and contraction unless it is sealed with an impervious skin, such as a plastic laminate.
Figure 4-17.-Three types of solid-core doors.
The second type is the stile-and-rail core, in which blocks are glued up as panels inside the stiles and rails. This type of core is highly resistant to warpage and is more dimensionally stable than the continuous-block core.
In addition to the solid lumber cores, there are two types of composition solid cores. Mineral cores (see fig. 4-17) consist of inert mineral fibers bonded into rigid panels. The panels are framed within the wood rails and stiles, resulting in a core that is light in weight and little affected by moisture. Because of its low density, this type of door should not be used where sound control is important.
The other type (not shown) has particleboard, flakeboard, or waferboard cores, consisting of wood chips or vegetable fibers mixed with resins or other binders, formed under heat and pressure into solid panels. This type of core requires a solid-perimeter frame. Since particleboard has no grain direction, it provides exceptional dimensional stability and freedom from warpage. Because of its low screw-holding ability, it is usually desirable to install wood blocks in the core at locations where hardware will be attached.
The doorjamb is the part of the frame that fits inside the masonry opening or rough frame opening. Jambs may be wood or metal. The jamb has three parts: the two side jambs and the head jamb across the top. Exterior doorjambs have a stop as part of the jamb. The stop is the portion of the jamb that the face of the door closes against. The jamb is 1 1/4 inches thick with a 1/2-inch rabbet serving as a stop.
Wood jambs are manufactured in two standard widths: 5 1/4 inches for lath and plaster and 4 1/2 inches for drywall. Jambs may be easily cut to fit walls of any thickness. If the jamb is not wide enough, strips of wood are nailed on the edges to form an extension. Jambs may also be custom made to accommodate various wall thicknesses.
Standard metal jambs are available for lath and plaster, concrete block, and brick veneer in 4 3/4-, 5 3/4-, 6 3/4-, and 8 3/4-inch widths. For drywall construction, the common widths available are 5 1/2 and 5 5/8 inches.
The sill is the bottom member in the doorframe. It is usually made of oak for wear resistance. When softer wood is used for the sill, a metal nosing and wear strips are generally included.
The brick mold or outside casings are designed and installed to serve as stops for the screen or combination door. The stops are provided for by the edge of the jamb and the exterior casing thickness (fig. 4-18).
Figure 4-18.-Parts of an exterior doorframe.
Doorframes can be purchased knocked down (K. D.) or preassembled with just the exterior casing or brick mold applied. In some cases, they come preassembled with the door hung in the opening. When the doorframe is assembled on the job, nail the side jambs to the head jamb and sill with 10d casing nails. Then nail the casings to the front edges of the jambs with 10d casing nails spaced 16 inches OC.
Exterior doors are 1 3/4 inches thick and not less than 6 feet 8 inches high. The main entrance door is 3 feet wide, and the side or rear service door is 2 feet 8 inches wide. A hardwood or metal threshold (fig. 4- 19) covers the joint between the sill and the finished floor,
The bottom of an exterior door may be equipped with a length of hooked metal that engages with a specially shaped threshold to provide a weatherproof seal. Wood and metal thresholds are available with flexible synthetic rubber tubes that press tightly against the bottom of the door to seal out water and cold or hot air. These applications are shown in figure 4-20. Manufacturers furnish detailed instruction for installation.
Figure 4-20.-Thresholds providing weatherproof seats.
Of the various types of doors, the swinging door is the most common (fig. 4-21 ). The doors are classed as either right hand or left hand, depending on which side is hinged. Stand outside the dear. If the hinges are on your left-hand side, it is a left-hand door. If the hinges are on your right, it is a right-hand door. For a door to swing freely in an opening, the vertical edge opposite the hinges must be beveled slightly. On a left-hand door that swings away from the viewer, a left-hand regular bevel is used; if the door opens toward the viewer, it has a left-hand reverse bevel. Similarly, if the hinges are on the right and the door swings toward the viewer, it has a right-hand reverse bevel.
Figure 4-21.-Determining door swings.
A door that swings both ways through an opening is called a double-acting door. Two doors that are hinged on opposite sides of a doorway and open from the center are referred to as "double doors"; such doors are frequently double acting. One leaf of a double door may be equipped with an astragal an extended lip that fits over the crack between the two doors. A Dutch door is one that is cut and hinged so that top and bottom portions open and close independently.
INSTALLING THE EXTERIOR D OORF RAME
Before installing the exterior doorframe, prepare the rough opening to receive the frame. The opening should be approximately 3 inches wider and 2 inches higher than the size of the door. The sill should rest firmly on the floor framing, which normally must be notched to accommodate the sill. The subfloor, floor joists, and stringer or header joist must be cut to a depth that places the top of the sill flush with the finished floor surface.
Line the rough opening with a strip of 15-pound asphalt felt paper, 10 or 12 inches wide. In some structures, it may be necessary to install flashing over the bottom of the opening. The assembled frame is then set into the opening. Set the sill of the assembled doorframe on the trimmed-out area in the floor framing, tip the frame into place, center it horizontaly, and then secure it with temporary braces.
Using blocking and wedges, you should level the sill and bring it to the correct height (even with the finished floor). Be sure the sill is level and well supported. For masonry wall and slab floors, the sill is usually placed on a bed of mortar.
With the sill level, drive a 16d casing nail through the side casing into the wall frame at the bottom of each side. Insert blocking or wedges between the trimmer studs and the top of the jambs. Adjust the wedges until the frame is plumb. Use a level and straightedge for this procedure (fig. 4-22).
Figure 4-22.-Plumbing an exterior doorjamb.
After the installation is complete, a piece of 1/4-or 3/8- inch plywood should be lightly tacked over the sill to protect it during further construction work. At this time, many Builders prefer to hang a temporary door so the interior of the structure can be secured and provide a place to store tools and materials.
Hanging the door and installing door hardware are a part of the interior finishing operation and will be described later in this course.
PREHUNG EXTERIOR DOOR UNITS
A variety of prehung exterior door units are available. They include single doors, double doors, and doors with sidelights. Millwork plants provide detailed instructions for installing their products.
First, check the rough opening. Make sure the size is correct and that it is plumb, square, and level. Apply a double bead of caulking compound to the bottom of the opening, and set the unit in place. Spacer shims, located between the frame and door, should not be removed until the frame is firmly attached to the rough opening.
Insert shims between the side jambs and trimmer studs. They should be located at the top, bottom, and midpoint of the door. Drive 16d finishing nails through the jambs, shims, and into the structural frame members. Manufacturers usually recommend that at least two of the screws in the top hinge be replaced with 2 1/4-inch screws. Finally, adjust the threshold so that it makes smooth contact with the bottom edge of the door. After a prehung exterior door unit is installed, the door should be removed from the hinges and carefully stored. A temporary door can be used until final completion of the project.
Place additional wedges between the jambs and stud frame in the approximate location of the lock strike plate and hinges. Adjust the wedges until the side jambs are well supported and straight. Then secure the wedges by driving a 16d casing nail through the jamb, wedge, and into the trimmer stud. Finally, nail the casing in place with 16d casing nails. These nails should be placed 3/4 inch from the outer edges of the casing and spaced 16 inches OC.