Project Guide

How to Install Split-Jamb Interior Doors

1
Choose a Door and Determine Door Swing
Side by side split-jamb doors that open from the left or right.
  • The first step is choosing the correct door to install.
  • Like slab doors, split-jamb doors can come in a variety of styles and sizes, so measure your opening and choose one that fits your space.
  • Choose whether you want the door to swing open to the left or to the right. 
  • If you are left-handed, consider having the knob on the left when the door opens to you. Similarly, if you are right-handed, you will likely want the knob on the right when the door opens to you.
  • If you are right-handed, consider having the knob on the right when the door opens to you.
2
Square and Plumb the Stud Opening
A man using a level to ensure a door frame is straight.
  • Use a carpenter square or level to make sure the threshold is completely level.
  • The hinge side of the opening should be plumb, and the top corners should be perfectly squared off.
3
Place the Door into the Opening
Two men placing a door into an open frame.
  • Have a partner help while you center the door into the opening.
  • Insert the bottom first, then lift the top into place.


Tip: If you are staining or painting your door after installation, it should be sealed with two coats on all six sides, including the edges. This will restrict moisture penetration. 

4
Secure Shims into the Frame
A man securing shims into the door frame.
  • Open the door and work from the inside.
  • Block and shim the jamb at the hinge locations and above the jamb with 8d finishing nails.
  • If your door is larger and has more hinges than a standard door, you will have to use additional shims above each hinge.
  • Double-check to make sure that the door is still square and plumb. Adjust the shims as needed.
  • Follow these same steps to shim the jamb on the lock side of the door.


Tip: If you use tapered shims, alternate the direction in which they are inserted.

5
Nail into the Frame
A man nailing in the frame of a door.
  • Work from approximately six inches below the top of the frame, driving 8d finishing nails into the hinge side of the frame. 
  • Penetrate through the jamb and shim, making sure the frame remains square and plumb.
  • Drive another nail approximately six inches above the bottom of the frame, and the third nail into the middle.
  • Follow these same steps to secure the lock side of the door.
  • Use a shim behind each nail and trim them with a utility knife when this task is complete.
6
Secure the Frame Center
A man securing the center of a door frame with a nail gun.
  • Slide the second part of the frame into place.
  • Nail through the jamb stop and secure together.
  • Secure the trim to the wall with two side-by-side nails every 12 inches from top to bottom.


Tip: Do not drive the nails fully into the frame in case they need to be removed in the future.

7
Make Finishing Touches
A man securing a white door into place.
  • Remove the nails from the top and bottom of the frame.
  • Use a hammer to tap the frame into place, using a hammer until the gap is closed. 
  • Re-nail the frame to secure your final adjustments and countersink the nails that were left in place.
  • Install the door knob and lockset, if applicable.