How to Install Split-Jamb Interior Doors

Quickly install pre-hung split-jamb doors

1-2 hours
Install Split-Jamb Interior Doors

Split-jamb pre-hung doors work well in situations where the rough frame is wider than a standard opening. They feature jambs that are split in half lengthwise, and the trim casing is already attached to each edge of the jamb, so no mitering is necessary.

With a split-jamb door, each half of the jamb is installed separately, beginning with the side that holds the hinges. Once the first half is completely installed, the second half slides neatly into place using a tongue and groove joint. This guide will help you to install split-jamb doors in just two easy steps.

Tip: When ordering a pre-hung door, make sure you specify the wall's overall thickness, and remember that the jambs ordered for plaster-covered walls are different than those for walls finished with drywall.

What You'll Need

Separate the two halves of the jamb
Separate two halves jamb - Split-Jamb Interior Doors

• Set the side with the door stop in the opening and tack through the casing about 12 inches from the top.
• Block and shim the jamb at the hinge locations and above the jamb.
• Plumb and square the unit.
• Nail through the jamb (not the stop) and into the door frame with 6d finish nails.

Cut the shims flush with the first half of the jamb
Cut shims flush first half jamb - Split-Jamb Interior Doors

• Inset the other half of the split-jamb into the first half and gently push it into place until the casing reaches the wall.
• Use 6d finish nails to nail through both halves of the jamb right in the center of the stop.
• Nail the casing to the wall with 4d finish nails.