Project Guide

How to Install Split-Jamb Interior Doors

Choose a Door
  • The first step a 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.
Determine the Desired Door Swing
  • 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.
  • If you are right-handing, consider having the knob on the right when the door opens to you.
Square and Plumb the Stud Opening
  • Use a carpenter square 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.
Place the Door into the Opening
  • 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 6 sides, including the edges. This will restrict moisture penetration. 

Secure Shims into the 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’ll need to use additional shims above each hinge.
  • Double check and make sure 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’re using tapered shims, alternate the direction in which they are inserted.

Nail Hinges into the Frame
  • Work from approximately 6-inches below the top of the frame, and drive 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 6-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.
Secure the Frame Center
  • Slide the second part of the frame into place.
  • Nail through the jamb stop and secure them together.
  • Secure the trim to the wall with two side-by-side nails every 12-inches top to bottom.

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

Make Finishing Touches
  • Remove the nails from the top and bottom of the frame 
  • Use a hammer to tap the frame over 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 know and lockset, if applicable.