Learn About Single, Double Doors

Door units, without pre-hanging, are also called “slabs”. We sell our Knotty Alder doors as single doors or in pairs (double doors). Generally speaking, double doors are two/each of the single doors. For example, if you order a double door in our Square Top Rail style, the door will be two of the single doors positioned side by side.

For the Top Rail Arch style doors (in both raised panel and plank styles), 1-3/8” thick double doors have the normal Top Rail Arch on each of the doors of the pair. However, if you upgrade to 1-3/4” thick doors in these TRA styles, the Top Rail is arched over the entire double door, or what we call a “Top Rail Arch Pair”. See below for these comparisons.

If you choose to purchase a pre-hung double door, the entire double door is framed with a double door jamb. In this case, you’ll choose one of doors as “active”, with a working handle or lockset. The other door of the pair is inactive (still opens and closes, but no working knob or handle), and includes a “T-Astragal” attached to the door edge for latching the active door. Flush bolts (top only for Interior doors, and both top and bottom for Exterior doors) are included to secure the inactive door in the closed position. A variety of active door, handing and swing choices are available, and can be found under the “Select Handing and Swing” drop down list, under pre-hanging.

In addition to normal “swinging” doors, we can pre-hang your double doors in either “ball catch” or “Bipass” configurations. These options are often used for double closet doors. These choices are available with pre-hanging, under the “Select Handing and Swing” options.

How Do I Measure Height & Width?

The first step in measuring the height and width of your new door is to measure the rough opening where the door will be placed. Rough opening means the opening of the stud wall structure prior to installing the door frame (door jamb). The process for determining the door height and width needed for your rough opening is as follows:

For Interior Doors

1. Measure the height of the rough opening, from the floor to the bottom of the upper stud of the opening (see the illustration below for this measurement). Measure the height on both corner edges of the opening, and then use the smallest of these two measurements. Then, subtract 3” from this height. This equals your needed door height.Example: Rough opening height = 83”. Door height needed = 80”, or 6’/8” (83” – 3” = 80”, or 6’/8”)
2. Measure the width of the rough opening, from inside of wall stud to inside of wall stud (see the illustration below for this measurement). Measure this in three places—top of the opening, middle of the opening, and bottom of the opening, and then use the smallest of these three measurements. Then, subtract 2” from this width. This equals your needed door width.Example: Rough opening measurement = 32”. Door width needed = 30”, or 2’/6” (32” – 2” = 30”, or 2’/6”)

If you are framing the rough opening for a new door (i.e. constructing the wall stud frame), just reverse the measurements above (i.e. select your desired finished door height and add 3” to this measurement, then select your desire finished door width and add 2” to this measurement).

For Exterior Doors

1. Measure the height of the rough opening, from the floor to the bottom of the upper stud of the opening (see the illustration below for this measurement). Measure the height on both corner edges of the opening, and then use the smallest of these two measurements. Then, subtract 3” from this height. This equals your needed door height.Example: Rough opening height = 99”. Door height needed = 96”, or 8’/0” (99” – 3” = 96”, or 8’/0”)
2. Measure the width of the rough opening, from inside of wall stud to inside of wall stud (see the illustration below for this measurement). Measure this in three places—top of the opening, middle of the opening, and bottom of the opening, and then use the smallest of these three measurements. Then, subtract 2” from this width. This equals your needed door width.Example: Rough opening measurement = 38”. Door width needed = 36”, or 3’/0” (38” – 2” = 36”, or 3’/0”)

If you are framing the rough opening for a new Exterior door (constructing the wall stud frame), just reverse the measurements above (i.e. select your desired finished door height and add 3” to this measurement, then select your desire finished door width and add 2” to this measurement).

 

Why does the opening need to be larger than the door and its jamb? First, the additional space provides room to adjust the door and jamb to the rough opening. The stud wall structures of rough openings are not always plumb and square, so providing extra space allows the installer to “shim” the jamb for a perfectly plumb, level and square door installation. Second, the additional height allows space for flooring material above the sub-floor such as carpeting, wood, tile for Interior doors, or the threshold for Exterior Doors. Last, walls may expand and contract slightly with the natural humidity and moisture changes that occur with changing seasons. So the extra space allows for minor adjustments to your door fit, as necessary.

Learn About Jamb Species, Types

Jamb Species

For both Interior and Exterior doors, we offer solid Knotty Alder wood jambs.

Jamb Types

Our Interior door jambs are flat jambs with an adjustable stop. We also offer bull-nosed kerfed flat jambs with an adjustable stop (for Interior doors only, at an extra charge). Kerfed flat jambs are slotted on the edge for wrapping the drywall corner bead (rounded drywall corners) into the jamb. Kerfed flat jambs provide for a clean opening, with drywall connecting directly to the door frame, and no case mouldings.

Exterior doors are framed with a more robust rabbeted jamb. A rabbeted jamb includes a non-adjustable stop cut into a solid Knotty Alder jamb, and Q-Lon Weatherstrip which is inserted into a kerf cut in the stop of the jamb. Weatherstrip is a durable foam rubber material used to seal the side and top edges of an Exterior door, to limit air transfer and exposure to outside elements. Our pre-hung Exterior doors also include an aluminum (Oil Rubbed Bronze color), adjustable Threshold (or sill), a metal walkway (or “ramp”) at the bottom of the entry unit. Pre-hung Exterior doors include 2” wide x 1-1/16” thick Brick Case Moulding for the exterior side of the door. The Brick Mould has an eased edge on the top two surface corners of the moulding (called “Eased 2 Edges”, or E2E). Exterior door hinges are more robust square corner 4.5” ball-bearing hinges. All of these elements combine to add the additional cost of pre-hanging an Exterior door.

How Do I Measure Jamb Width?

To choose the proper jamb with for your pre-hung door, you must determine the thickness of the wall where your door will be placed. Wall thickness includes the wall stud plus the sheetrock thickness. Normally, either 2×4 or 2×6 studs are used for wall framing. Sheetrock is usually either 1/2” thick or 5/8” thick. Determine your wall stud and sheetrock thickness and then use the charts below to select the proper jamb width to match your application.

Interior Jamb Widths

Flat (non-Kerfed) Interior door jambs are available in the following widths, to match the following wall stud and sheetrock thicknesses:

Solid Knotty Alder, Flat Jamb w/Adjustable Stop

Bull-nosed kerfed flat jambs for Interior doors are available in the following widths, to match the following wall stud and sheetrock thicknesses (Note: Kerfed flat jambs are more narrow than regular flat jambs, to allow for wrapping the drywall corner bead into the jamb):

Solid Knotty Alder, Bull-Nosed Kerfed Flat Jamb w/Adjustable Stop

Exterior Jamb Widths

Rabbeted jambs for Exterior doors are available in the following widths, to match the following wall stud and sheetrock thicknesses:

Solid Knotty Alder, Rabbeted Jamb

How Do I Choose Door Handing and Swing?

Handing & Swing refers to the side of the door which is hinged, and the way the door swings inside or outside of the room or home. Consider the way you would like your door to open when making this choice.

A simple way to understand handing is to stand in the doorway with your back against the jamb of the door where you want the hinges to be placed. From this position, if you want the door to open to your left, it is a left hand door. From this position, if you want the door to open to your right, it is a right hand door.

Next, determine if you want the door to swing inside or outside the room or home. Inside is an “inswing” door, and outside is an “outswing” door. Review the illustrations below to identify the way you would like your door to be handed and swing (Note:  These illustrations apply to Interior or Exterior single doors).

For Interior or Exterior double doors, one door is designated as “active” (operating knob or handle to open the door), and the other door is designated as “inactive” (still opens and closes, but no working knob or handle). The inactive door includes an attached T-astragal with flush bolts (top only for Interior doors, and both top and bottom for Exterior doors) to secure the door in the closed position. Review the illustrations below to select which side of your double door you would like active, and its handing and swing (inside or outside of the room or home).

In addition to these handing & swing options, we also offer Interior double doors with a “ball catch” or a “bipass” configuration. These double door options are most frequently used on closet door applications. For example, ball catches are typically used with “dummy” (non-active) handle sets, on outswing closet doors. Ball catch hardware is included at no additional charge on double ball catch doors, and track hardware is provided at no additional charge on double bipass doors. We do not bore for the dummy handle sets on these options. Review the illustrations below to select one of these Interior double door applications.

How Do I Choose the Right Bore Position? 

The bore position for your new door depends upon the type and function of the hardware (knob or handle) you desire to use on the door. Consult your hardware supplier for their recommendations. When you order a pre-hung door, we can bore your new door for a handle or lockset, at no extra charge. Our standard bore options and dimensions are documented in this section.

We offer both single bore and double bore options. Double bores are typically used on Exterior doors, with a lockset with deadbolt. Our bores include mortising the edge of the door for the latch (latch and dead bolt for double bore), and mortising the “strike” on the jamb leg where the latch inserts (or latch and deadbolt for double bore).

The knob or handle bore is 36” from the bottom of the door to the center of the bore hole, and the bore hole is 2-1/8” in diameter. For double bore options, the distance between the two bore holes is always 5-1/2” center to center (from the center of the diameter of the knob or handle bore to the center of the diameter of the dead bolt bore). Available “backsets” (the distance from the edge of the door to the center of the bore diameter) are:

Available Backsets

2-3/8”
2-3/4”

Review the following illustrations to select the bore and backset you desire for your new door.

Learn About Hinges

Factory pre-hanging ensures that hinge pockets are mortised square and precise, and that hinges are always flush on the door and frame. Hinges are included in the price of pre-hanging.

3.5”, square corner hinges are provided on all 1-3/8” thick Interior doors. 4” ball-bearing hinges are provided on all 1-3/4” thick Interior doors. More robust 4.5” ball-bearing hinges are provided on all 1-3/4” thick Exterior doors. Nine different hinge colors are available, at no additional cost.

Learn About Pre-Finishing

Factory pre-finishing is a hallmark of our company. Our pre-finishing experience began over 25 years ago, and our finishes are renowned in the door industry. We offer the highest quality factory-applied stains, glazes, and topcoats—available in 24 color options. Our pre-finishes are “fine furniture” quality, providing much higher quality and lower cost than on-site painting. And our pre-finished products are ready to install, further adding value by reducing time (and scheduling) in the construction process. A summary of our pre-finishing strengths includes:

• A minimum of 30 minutes per door hand-sanding—ensuring grain closure and perfect preparation prior to finishing
• Top quality catalyzed conversion varnish systems (similar to high-end pre-finished cabinets and fine furniture)
• Proprietary stain formulas created specifically for our environment and applied using HVLP (High Volume Low Pressure) and air-assisted spray guns—ensuring even tones with no blotchiness
• A “clean room”, dust-free environment not achievable on the jobsite—preventing small dust and dirt particles from settling on the product before drying
• Six-sided coating on doors, providing moisture seal on all sides, preventing warping. Our door warranty increases from one year to five years on our pre-finished options

Step-by-Step Process

Our step-by-step process pre-finishing process includes:

• Sanding preparation. A minimum of 30 minutes per door, starting with heavier 150 grain sand paper and working down to finer 180 grain sand paper. This ensures grain closure, required for a furniture quality finish.
• Stain coat. Using our proprietary, solvent based stains.
• Seal coat. Using top quality catalyzed conversion varnish to seal and protect the stained wood.
• Seal sand. Additional sanding to smooth the sealed surface and prepare for final top coat.
• Glaze (completed on Stain/Glaze color options only). Hand-wiped, solvent based glaze to beautifully shadow profiles and edges.
• Top coat. The top coat provides the final finish coat of the wood, again using top quality catalyzed conversion varnish. Top coat for Exterior doors is more robust, for exposure to outside elements, including a UV (Ultra-Violet light) inhibitor.

Pre-Finished Jambs (Pre-Hung Doors)

If you select a Knotty Alder jamb, either for your Interior or Exterior door, the jamb will be pre-finished matching the pre-finish color you select for your door. For the flat or kerfed flat jambs available on Interior doors, the jambs and stop are finished separately, providing for on-site adjustment of the stop without finish touch-up.

Color Options

24 color options are available, with eight colors in each of three groups:

• Stains
• Stains/Glazes – Brown
• Stains/Glazes – Red

Glazing beautifully shadows the profiles and edges of the door.

Please note that pre-finish colors illustrated on computer screens may not exactly match the actual pre-finished colors of the doors. We assume no liability for such color discrepancies, and encourage buyers to request color samples to ensure satisfaction.

Stains

Pre-finish colors illustrated on computer screens may not exactly match the actual pre-finished colors of the doors.

Stains/Glazes – Brown

Pre-finish colors illustrated on computer screens may not exactly match the actual pre-finished colors of the doors.

Stains/Glazes – Red

Pre-finish colors illustrated on computer screens may not exactly match the actual pre-finished colors of the doors.