Doors #

Skill Level: Intermediate (Level 2) #

Estimated Time: 30-45 Minutes Per Door #

Introduction #

A pre-hung door is a complete unit — the door slab, jamb frame, and hinges come pre-assembled from the manufacturer, ready to be set into a rough opening and secured. Learning to install a pre-hung door properly is one of the most essential finish carpentry skills. Unlike a slab-only replacement where you mortise hinges and fit the door to an existing jamb, a pre-hung installation gives you full control of the jamb position, plumb, and reveal. For new construction, pre-hung doors are the standard. You’ll install dozens or even hundreds of them on a typical tract job, so developing a fast, repeatable method is essential to production speed and consistent quality.

In new construction, pre-hung interior doors are installed after framing is complete. The timing relative to drywall depends on the builder’s schedule and preferences. Some builders have doors set before drywall so the rockers can butt their sheets to the jambs. Others prefer doors to go in after drywall is hung and finished, which is the more common approach for finish carpenters. This pre-hung door guide covers post-drywall installation — the method you’ll use most frequently as a finish carpenter. The rough opening should already be framed, the drywall should be complete around the opening, and the door unit should be on site and verified before you begin.

The single most important concept when you install a pre-hung door is getting the hinge-side jamb perfectly plumb. Everything else follows from that. If the hinge side is plumb, the door will swing freely without binding, the reveals will be consistent, and the latch will engage the strike plate cleanly. If the hinge side is out of plumb, the door will swing open or closed on its own, the reveals will be uneven, and you’ll fight the installation every step of the way. Experienced carpenters spend most of their time on the hinge side and treat the strike side as a secondary adjustment.

Pre-hung doors come in standard sizes — 6’8″ (80″), 7’0″ (84″), and 8’0″ (96″) heights are the most common for interior residential work. Widths range from 1’6″ (18″) for small closets up to 3’0″ (36″) for bedroom and bathroom entries. The rough opening should be approximately 2″ wider and 2″ taller than the door unit to allow room for shimming and adjustment. Before you start the installation, always verify that you have the correct door for the opening — check the size, swing direction (left-hand or right-hand), and style against the door schedule or plans.

Before You Begin: Pre-Hung Door Prep #

Prerequisites #

• The rough opening is properly sized — typically 2″ wider and 2″ taller than the door unit (e.g., a 2’8″ x 6’8″ door needs a 34″ x 82″ rough opening)
• Framing is complete, solid, and the jack studs and header are securely nailed
• Drywall is complete — hung, taped, mudded, and sanded around the door opening
• The subfloor or finished floor is installed and level at the door opening — if flooring hasn’t been installed, you need to know the finished floor height
• The correct pre-hung door unit is on site, verified for size, swing direction, and style per the plans or door schedule
• Door packaging is intact — do not remove the factory shipping brace or cardboard spacers until you’re ready to install

What You Need To Know #

• Door swing direction must match the plans. Stand on the side the door swings toward you — if the hinges are on the left, it’s a left-hand door; hinges on the right, it’s a right-hand door. Verify this before removing the door from its packaging.
• The hinge side gets plumbed first — this is the most critical step in the entire installation. Everything else follows from a plumb hinge-side jamb.
• Check the rough opening for plumb before starting. If the jack studs are severely out of plumb (more than 1/2″ over the height), you may need to address the framing before setting the door.
• Shimming is the technique that makes or breaks the installation. Shims must be placed at every hinge location and at the strike plate, at minimum. Additional shims go at the top and bottom of each side jamb and behind the header.
• The reveal — the gap between the door slab and the jamb — should be consistent all the way around the door. The standard reveal is approximately 1/8″ (the thickness of a nickel). Uneven reveals are the most visible sign of a poorly installed door.
• Standard interior door heights are 6’8″ (80″), 7’0″ (84″), and 8’0″ (96″). Standard widths range from 1’6″ (18″) to 3’0″ (36″). Always confirm the size matches the schedule before opening the packaging.
• The gap under the door (between the bottom of the slab and the finished floor) depends on the flooring type. Typical clearance is 3/8″ to 1/2″ for hard floors, 3/4″ for carpet. Check with the builder or GC for the required gap.

Pre-Hung Door Tools Required #

Power Tools #

• Drill/driver (cordless) — for driving screws through hinge jamb into framing as reinforcement
• 18-gauge brad nailer (pneumatic or cordless battery-powered) — for nailing through jamb and shims into framing

Hand Tools #

• 4-foot level — essential for checking plumb on both side jambs and level on the header; this is the most important tool for the job
• 6-foot level — for 7’0″ and 8’0″ tall doors where a 4-foot level doesn’t give enough read
• Tape measure (16′ or 25′) — for measuring rough opening dimensions and reveal gaps
• Pencil — sharp carpenter’s pencil for marking shim locations
• Hammer — for tapping shims and making minor adjustments
• Wood shims (cedar) — tapered wooden shims for plumbing and securing the jamb in the opening
• Utility knife — for scoring shims flush with the jamb before snapping them off
• Handsaw (optional) — for trimming the bottom of jamb legs if needed for floor clearance adjustments

Supplies #

• 18-gauge brad nails, 2″ — for nailing through jamb and shims into framing
• 16-gauge finish nails, 2-1/2″ — for through-jamb nailing into framing at shim locations for a stronger hold
• Wood shims (cedar) — tapered shims, always used in pairs (opposing tapers) for a flat, adjustable shim point
• Construction adhesive (optional) — for bonding shims to framing on critical installations
• #9 x 3″ wood screws (2-3 per door) — for driving through the hinge plate into the framing for structural reinforcement, replacing the short factory hinge screws

Materials #

• Pre-hung door unit — Verify the correct swing direction (left-hand or right-hand), size (width x height), and style before removing from packaging. The unit includes the door slab, jamb frame (two side jambs and a header jamb), and hinges already mortised and installed. Most interior pre-hung doors come with two or three hinges depending on the door height and weight. Do not remove the factory shipping brace or cardboard spacers that hold the slab centered in the frame until the door is plumbed and secured — these spacers maintain the correct reveal during installation.

Pre-Hung Door Installation Process #

Step 1: Verify the Rough Opening #

Before you move the pre-hung door unit into position, take a minute to verify the rough opening. Catching problems now saves significant time and frustration later. This step is especially important on production jobs where framers may have built some openings out of spec.

• Measure the width of the rough opening at the top, middle, and bottom. It should be approximately 2″ wider than the door unit (for a 2’8″ door, the rough opening should be about 34″). If the opening is too tight, the door won’t fit; if it’s too wide (more than 2-1/2″ of space per side), you’ll need extra-long shims or blocking to fill the gap.
• Measure the height of the rough opening on both sides. It should be approximately 2″ taller than the door unit. If the opening height varies significantly from one side to the other, the header or subfloor may not be level — note this and plan your shimming accordingly.
• Check both jack studs for plumb using your 4-foot level. Place the level against the face of each jack stud and note the direction and degree of any lean. You’ll compensate for this with shims, but knowing the condition ahead of time tells you where you’ll need the most shimming.
• Identify which side gets the hinges per the door schedule or floor plan. Look at the plans — the door symbol indicates swing direction. The hinge side is the side the door pivots from; the strike side (latch side) is where the door latches when closed.
• Verify the floor is level across the bottom of the opening. Place your level on the subfloor spanning from one jack stud to the other. If the floor is out of level, you’ll need to adjust the door height on one side to compensate — the bottoms of the jamb legs get trimmed or shimmed so the head jamb remains level.

Step 2: Position the Door Unit #

With the rough opening verified, it’s time to move the pre-hung door unit into position. Keep the factory shipping brace and cardboard spacers in place — they hold the slab centered in the jamb frame with the correct reveal, and you’ll rely on that consistent spacing during installation.

• Remove the outer packaging (cardboard, plastic wrap, corner protectors) but leave the shipping brace across the bottom of the jamb legs and any cardboard reveal spacers between the slab and jamb. These factory spacers maintain the correct gap around the slab while you shim and nail.
• Lift the door unit and set it into the rough opening from the side the door will open toward. Most interior doors are set from the room side (the side with the door stop already applied to the jamb).
• Center the unit in the opening side to side. You should have roughly equal space on both sides between the jamb and the jack studs. Don’t worry about exact centering — the shims will handle final positioning.
• Check the gap between the top of the slab and the header jamb. It should be consistent across the width — if it tapers, the unit may be tilted or the header is not level. The factory spacer at the top should maintain this gap.
• Make sure the jamb edges are flush with the finished wall surface on both sides of the opening. The jamb width should match the wall thickness (drywall + stud + drywall). If the jamb is too narrow and sits recessed behind the drywall, you’ll need jamb extensions. If it’s too wide and protrudes past the drywall, plane it flush before proceeding.

Step 3: Shim and Plumb the Hinge Side #

This is the most critical step in the entire pre-hung door installation. A perfectly plumb hinge-side jamb means the door will hang straight, swing freely without resistance, and stay at whatever position you leave it. An out-of-plumb hinge side means the door will swing open or closed on its own under gravity, and no amount of adjustment on the strike side will fix it. Take your time here — this step is worth getting right.

• Start by placing shims behind the hinge-side jamb at each hinge location. For a standard 6’8″ door with three hinges, you’ll shim behind the top hinge, the middle hinge, and the bottom hinge. Always use shims in opposing pairs (one from each side) so the shim point is flat and adjustable — sliding the shims past each other increases or decreases the thickness.
• Place your 4-foot level against the face of the hinge-side jamb. Read the bubble carefully. Adjust the shims in or out until the bubble is perfectly centered. Check plumb on the face (side to side) and also on the edge (front to back). Both readings must be plumb.
• Add additional shim points between the hinges if needed — especially on taller doors (7’0″ and 8’0″ — see the 8’0″ hollow core guide and 8’0″ solid core guide for detailed tall-door shimming notes). You want the jamb fully supported, with no bowing or flexing between shim points. A good rule of thumb is a shim point every 16″ to 24″ along the jamb length.
• Check that the jamb is straight by sighting down the edge or holding your level along the full length. The jamb should not bow in or out between shim points. If it does, adjust the shims at those locations to bring it into a straight line.
• Verify the reveal between the slab and the hinge-side jamb. With the factory spacers in place, the reveal should be consistent from top to bottom — approximately 1/8″. If the reveal varies, the jamb may be bowed or the shims need further adjustment.

Pro Tip: When checking plumb, hold the level against the jamb and read it at eye level. Looking at the bubble from above or below introduces parallax error. On production jobs where you’re hanging dozens of doors, develop the habit of checking plumb in one consistent spot — many experienced carpenters place the level at the top hinge and adjust the bottom, then verify by moving the level to check the full length. Consistency in your method leads to consistency in your results.

Step 4: Nail the Hinge Side #

Once the pre-hung door hinge-side jamb is plumb and straight, it’s time to lock it in position. Nailing through the jamb and shims into the framing secures the jamb permanently. After this step, you should not need to move the hinge side again — so double-check your plumb reading one last time before you start nailing.

• Drive two 16-gauge finish nails (2-1/2″) through the jamb and through the shims into the jack stud at each shim location. Place the nails where they’ll be covered by the door stop (if the stop is separate) or where they’ll be least visible. Nailing through the shims is critical — nails that miss the shims don’t provide adequate holding power.
• Start at the top hinge shim location and work down. After nailing the first shim point, re-check plumb before nailing the next. Nailing can sometimes shift the jamb slightly, so verify as you go.
• For structural reinforcement, replace one factory hinge screw (the top screw in the top hinge) with a #9 x 3″ wood screw. This screw passes through the hinge plate, through the jamb, through the shims, and into the jack stud and potentially the header. This single screw carries the weight of the door and prevents the hinge side from sagging over time — especially important on heavy solid-core doors (see the 6’8″ solid core guide and 8’0″ solid core guide for complete details on structural screw placement for heavy doors).
• After nailing all hinge-side shim points, do a final plumb check on both the face and edge of the jamb. If anything shifted during nailing, address it now before moving to the strike side.

Step 5: Adjust the Strike Side #

With the hinge side locked in, the strike side (latch side) is adjusted to match. The goal is a consistent reveal between the slab and the strike-side jamb, matching the reveal on the hinge side. Close the door and use the slab as your reference — the door itself becomes your straightedge for setting the strike-side jamb position.

• Close the door gently and examine the reveal between the slab and the strike-side jamb. The gap should be approximately 1/8″ — consistent from top to bottom and matching the hinge-side reveal.
• Check the reveal at the top (header jamb) as well. The gap between the top of the slab and the header should also be approximately 1/8″ and consistent across the width of the door.
• Place shims behind the strike-side jamb at the strike plate location, plus at the top and bottom of the jamb. Adjust the shims until the reveal is consistent. Slide the shims in to push the jamb closer to the slab (reducing the gap) or pull them out to move the jamb away (increasing the gap).
• Add additional shim points between the top and bottom as needed — aim for a shim point every 16″ to 24″, same as the hinge side. The strike-side jamb must be fully supported to prevent bowing when someone pushes the door closed.
• Once the reveal is consistent, nail through the jamb and shims at each shim point using two 16-gauge finish nails (2-1/2″) per location. Nail at the shim points only — nails driven into unsupported sections of jamb will pull the jamb toward the framing and create a bow.

Pro Tip: When adjusting the strike side, close the door and look at the reveal from the hinge side. Your eye can pick up inconsistencies more easily when you’re looking at the reveal as a continuous line from top to bottom. If the reveal is wider at the top than the bottom (or vice versa), the strike-side jamb isn’t parallel to the slab — adjust the shims at the top or bottom to correct it. A consistent reveal is the hallmark of a professionally installed door.

Step 6: Shim at the Header #

The header jamb (the horizontal piece across the top) needs to be shimmed between the jamb and the rough opening header to prevent it from sagging or bowing. On most interior doors, the header shims are less critical than the side shims because the header doesn’t bear any significant load, but they still need to be done properly to maintain the reveal at the top of the slab.

• Place shims between the header jamb and the rough opening header at two or three points — one near each end and one in the center. Use opposing shim pairs for a flat contact surface.
• Close the door and check the reveal between the slab and the header jamb. It should be approximately 1/8″ and consistent across the full width. Adjust the header shims to achieve this gap.
• Nail through the header jamb and shims into the rough opening header with two 16-gauge finish nails per shim location. Place nails where they’ll be covered by the door stop or casing.
• Verify that the header jamb is level. Place your level across the top — it should read level or very close. If the header is out of level and the reveals are still consistent, the reveals take priority. The casing will cover any minor discrepancy in the header position.

Step 7: Check Door Operation #

Before you call this pre-hung door done, thoroughly test the operation. This is your quality check — catching problems now is easy, but catching them after casing and painting is expensive and time-consuming. Open and close the door several times and evaluate every aspect of the installation.

• Open the door fully (90 degrees or more) and release it. The door should stay put wherever you leave it. If it swings open by itself, the hinge side is leaning toward the opening. If it swings closed by itself, the hinge side is leaning away from the opening. Either condition means the hinge-side jamb is not perfectly plumb — go back and adjust.
• Close the door slowly and check for binding at any point in the swing. The slab should not contact the jamb anywhere except at the stop. If the door drags at the top or bottom, the jamb may not be plumb or the slab may be warped — check both.
• With the door closed, verify the reveal on all three sides (hinge, strike, and header). The reveal should be approximately 1/8″ and consistent. Sight down each side from one end to the other — any waviness or variation indicates a shim adjustment is needed.
• Check that the latch catches the strike plate cleanly. Push the door closed and verify the latch bolt engages without having to push or pull the door into position. If the latch doesn’t engage, the strike side may need shimming adjustment, or the strike plate may need to be repositioned.
• Verify the gap under the door (between the bottom of the slab and the floor). It should match the spec for the flooring type — typically 3/8″ to 1/2″ for hardwood or tile, 3/4″ for carpet. If the gap is wrong, the jamb legs may need to be trimmed or the entire unit raised with shims under the jamb legs.

Step 8: Score and Snap Shims #

The final pre-hung door step is trimming the shims flush with the jamb or wall surface. Protruding shims will interfere with casing installation and look sloppy. The key is to remove the excess without disturbing the shim position — a shim that shifts during trimming can change your carefully set reveal and plumb.

• Score each protruding shim with a utility knife right at the face of the jamb (or the drywall surface, whichever is the flush line you’re trimming to). Press firmly and make several passes to cut halfway through the shim thickness. Cedar shims score and snap cleanly; pine shims may take more scoring. Family Handyman has additional visual references for this technique.
• Snap the excess off by bending it toward the jamb. The shim will break cleanly along the scored line. If it doesn’t snap cleanly, score deeper and try again. The broken face should be flush with or slightly recessed from the jamb face.
• Do not use a handsaw, oscillating tool, or any powered cutting tool to trim the shims. The vibration from cutting can shift the shim position and move your carefully plumbed jamb. Scoring and snapping is the correct technique — it applies zero vibration to the installed shim.
• Score and snap shims on both sides of the wall at each shim point. Remember, the shims protrude on both the room side and the hallway/adjacent room side of the opening.
• After all shims are trimmed, remove the factory shipping brace from the bottom of the jamb legs and any remaining cardboard spacers between the slab and jamb. Open and close the door one final time to confirm everything still operates correctly.

Pro Tip: Keep your utility knife blade sharp for scoring shims. A dull blade requires more pressure, which pushes against the shim and can shift it. Swap in a fresh blade at the start of each door-hanging session. On a production job where you’re hanging 20+ doors, the blade will dull noticeably by mid-day — change it when scoring starts to require effort.

Pre-Hung Door Quality Check #

Before moving on to the next pre-hung door, run through this final checklist. Every item should pass — if anything fails, address it now rather than coming back after casing is installed.

• Hinge-side jamb is perfectly plumb (check with level on face and edge)
• Reveals are consistent at approximately 1/8″ on all three sides (hinge, strike, and header)
• Door swings freely without binding at any point in the arc
• Door stays put at any position when released — does not swing open or closed on its own
• Latch engages the strike plate cleanly without forcing the door
• All shims are tight — no rattling or movement when the door closes
• All shims are scored and snapped flush with the jamb and wall surfaces
• Gap under the door is correct for the specified flooring type (3/8″ to 1/2″ for hard floors, 3/4″ for carpet)
• Jamb edges are flush with the finished wall surface on both sides of the opening
• Factory shipping brace and spacers have been removed

Pre-Hung Door Troubleshooting #

Door Swings Open or Closed by Itself #

This pre-hung door problem means the hinge-side jamb is not plumb. If the door swings toward the hinge side (opens on its own), the top of the hinge-side jamb is leaning into the room. If it swings toward the strike side (closes on its own), the top of the hinge-side jamb is leaning into the adjacent space. Remove the nails at the top or bottom hinge shim location, adjust the shims to bring the jamb into plumb, and re-nail. Even 1/16″ out of plumb can cause a door to drift — this is why the hinge side must be dead plumb.

Top of Door Hits the Jamb When Closing #

The header shims are too tight, pushing the header jamb down into the slab. This reduces the reveal at the top and can cause the slab to contact the header when swinging. Remove the header nails, back the shims off slightly to increase the reveal at the top, and re-nail. Alternatively, the hinge-side jamb may be out of plumb with the top leaning toward the strike side — check plumb on the hinge side and correct if needed.

Door Binds at the Latch Side #

The strike-side jamb is too close to the slab at one or more points. Close the door and identify where the binding occurs — top, middle, or bottom. The jamb is bowed inward at that location. Remove the nails at the shim point nearest the bind, adjust the shims to push the jamb away from the slab slightly, and re-nail. After adjustment, close the door and verify the reveal is consistent from top to bottom. On pre-hung doors, binding can also mean the slab is warped — check the slab with a straightedge to rule this out.

Large Gap at the Bottom of the Door #

The rough opening is too tall for the door unit, or the jamb legs are sitting on the subfloor instead of at the finished floor height. If flooring hasn’t been installed, verify the finished floor height with the GC and shim the jamb legs up from the subfloor to the correct height. If flooring is already installed and the gap is still too large, the rough opening was framed too tall. You can add an additional shim between the header jamb and the rough opening header to lower the entire unit, but this has limits — if the opening is more than 1″ too tall, the framing should be corrected.

Door Won’t Latch #

The strike plate is misaligned with the latch bolt. Close the door and observe where the latch bolt contacts the strike plate — it may be hitting above, below, or to one side of the strike plate opening. The most common cause is a strike-side jamb that is not in the correct position. Adjust the strike-side shims to move the jamb in or out until the latch bolt aligns with the strike plate opening. If the alignment is off vertically (latch hits above or below the strike plate), the strike plate may need to be repositioned — chisel the mortise slightly higher or lower and remount the plate. On a properly shimmed door, the factory-positioned strike plate should align without modification.

Reveals Are Inconsistent #

On a pre-hung door, inconsistent reveals mean the jamb is not following the slab consistently. The most common cause is insufficient shim points — the jamb bows between shim locations due to pressure from nailing or from the door being pushed against it. Add shim points between existing ones to provide continuous support. Another cause is a warped door slab — hold a straightedge across the face of the slab to check for twist or bow. A twisted slab will produce a reveal that looks correct at the hinge and strike sides but is off at the header, or vice versa. Severely warped slabs should be returned to the supplier.

Door Variant Guides #

• How to Install a 6’8″ Solid Core Pre-Hung Interior Door — Standard height, heavier door. Weight-specific shimming, structural screws, and handling techniques.
• How to Install an 8’0″ Hollow Core Pre-Hung Interior Door — Taller door, standard weight. Ladder work, longer levels, additional shim points, and tall rough opening considerations.
• How to Install an 8’0″ Solid Core Pre-Hung Interior Door — The most challenging variant. Two-person technique, slab removal, and maximum structural reinforcement.

Related Guides #

• How to Install Exterior Door Casing
• How to Install an Exterior Door
• How to Install a Cased Opening
• How to Install a Door Jamb Extension
• How to Install a Lockset on a Door