Level of Difficulty:Intermediate Do-It-Yourselfer – Moderate
Interior doors are so pervasive in our daily lives that we scarcely seem to notice them anymore. Yet a properly selected and installed interior door can enhance any décor and perhaps force us to take notice. This is why it is important to choose the right model.
The difference between a prehung door and a slab door is that the prehung door is built into a jamb and has the hinges in place. This means that once it is inserted in the rough stud opening, it only needs a lockset and trim and it is finished. Hanging a slab door requires building the jamb and installing hinges.
Installing or replacing an interior door is a simple task if you follow the proper steps and have the right tools.


  • Wood chisel set
  • Hammer
  • 4" level
  • Nail punch
  • Pry bar
  • Screwdriver
  • Drill

  • Utility knife
  • 2-1/8" door hole drill bit
  • 7/8" spade drill bit
  • Door lock installation kit
  • Wood-cutting knife
  • Hand plane


  • 8d casing nails and finishing nails
  • Cedar shims
  • 4 ½” door jamb stock
  • Lockset

  • Door slab
  • Screws
  • Wood filler
  • Doorstop mouldings


Almost all interior doorframes are made up of similar parts. At the top is the head jamb and this is flanked on each side of the door frame by a side jamb, one for the lock side and the other on the hinge side. The doorframes are installed in a “rough stud opening,” a hole in the wall framed by wall studs and a header.
Once the jamb is in place any design of door, or “slab” from colonial patterns to French doors can be installed using specific door knobs and hinges to match.


Having a good, 4" level is very important for a good installation. Check the accuracy by laying it on a flat surface and then note the position of the bubble. Now turn the level over end for end and re-check the bubble. The bubble should be in exactly the same spot. If not, get another level.


The rough opening should be 2 to 2¾” wider than the door and 1" to 2" higher. All corners should be 90°. Add the width of the door slab to make sure that the combined door unit will fit in the door frame.
The width of an interior door slab (another name for just the door without the frame) varies between 24" and 36". Typically, 30" doors are used for every room in the house except for the door that leads to the basement where it should be 32" wide (or greater). Note that if you want to keep your washer and dryer in the bathroom, you should install a 32" door (or greater), if space allows.
When we talk about a 30" door, we are talking about the width of the door slab itself. The frame adds an additional 2" in width and 1" height. Standard doors are 80? high. You must allow a clearance of ½” between the bottom of the door and the floor.


Both the number of hinges used and their size depends on the type of door and how thick it is. Hollow core interior doors usually have two hinges while the heavier, solid-core doors should have at least three.


If placing the door between adjoining rooms that will have carpet or a hardwood added later on both jamb sides can be adjusted from 3/8" to 1" above the floor depending on the material that will be installed.


If you plan on painting or staining your door do so before you install it. By laying the door flat, the paint or stain will be much easier to apply and will not run or leave drip lines.

1.1. Measure the door frame between the jack studs (vertical studs) starting under the header and at floor level to make sure the combined width of the door slab and the door jamb will fit.
Subtract ¾” off each side of the door header to make allowance for the thickness of the two door jambs (1½” total) as they will be nailed to each side.

1.2. Cut the door jambs to these measurements.

1.3. Assemble the doorframe on flat surface.

1.4. Attach the head jamb to the two sides using glue and finishing nails.

2.1. Place the frame in the opening.

2.2. Insert cedar shims firmly between the jambs and the wall on both sides, one under the other over top.

2.3. Make sure the sides are perfectly upright with a level.
Hammer the shims lightly to adjust.

2.4. Drill screws through the frame and shims to hold the jambs in place but do not tighten.

2.5. Measure the horizontal gap between the jambs at three points: top, middle and bottom.
These should be equal so that the door slab will fit perfectly. If not back out the screws and adjust the shims. When the measurements match tighten the screws to secure the doorframe.

2.6. Trim off the shims with a utility knife.

3.1. Turn the door on its edge and anchor between two sawhorses to provide steadiness for working on the hinges.
Putting the door between the legs will work as well.

3.2. Depending on the thickness of the door, determine the location of the hinge butt and draw the outline on the door edge. The top hinge should be 7″ from the top and the bottom hinge should be 11″ from the bottom.

3.3. Measure de distance between both hinges.

3.4. Copy these marks onto the door frame.
Start from the top. Do not mark 11″ from the floor as there is a gap of ½” under the door.

3.5. Use a wood chisel to cut the mortises (notches) in the edge of the door for the hinges.
Go no deeper than the thickness of the hinge and smooth the bottom of the mortise so that hinge is flush with the edge of the door.

3.6. Predrill the holes for the hinge plates and attach hinges to the door with screw supplied with the hinges.

4.1. Fit the door inside the frame and shim the bottom so that the top of the door slab and the sides have equal spacing.

4.2. Verify that the marks on the door frame are correct. If not, adjust.

4.3. Remove the door slab.

4.4. Hollow out the mortises on the doorframe for the hinges with the wood chisel.

4.5. Place the door slab back into the door frame and attach the door hinges l with screws.

4.6. Make sure the door is plumb and swings freely without rubbing on the door frame.

5.1. Position the handle template on the door and drill the handle hole with a 2 1/8″ hole drill bit.
If the hole saw is not capable of cutting all the way through, turn the door over and use the pilot hole to drill from the opposite side.

5.2. Drill the latch hole in the door edge with a 7/8″ spade bit.

5.3. Position the latch in the 7/8″ hole on the door and mark around the outside of the face plate.

5.4. Cut the recess for the strike plate with a 1″ wood chisel.
Be careful to only go as deep as the thickness of the strike plate.

5.5. Place face plate and latch assembly into the hole and hold in place with screws supplied with the lockset.

6.1. Swing the door so that the latch touches on the doorframe and mark the position of the latch on the doorframe jamb.

6.2. Drill the hole for the latch with the 7/8″ spade bit.
The hole should be as deep as the latch is long.

6.3. Cut the mortise for the strike plate using a wood-cutting knife.

6.4. Assemble the door handle as per the instructions given with the lockset.
Test the door swing and adjust the strike plate as needed.

6.5. Cut the doorstop to fit the door jamb.
Close the door and nail the door stop around the frame with finishing nails.

6.6. Set the nails with a nail punch and fill the holes with wood filler.