What is a Pre-Hung Door?
A prehung door is a complete, ready-to-install unit designed to simplify hanging a door in a rough opening. Installing a pre-hung interior door doesn’t have to be complicated. Because the door comes already mounted in its frame, the process is faster and more precise—as long as each step is done carefully. Follow these simplified steps for a smooth installation and professional-looking results.
Step One:
Check the Framing & Rough Opening
Confirm the rough opening is the correct size, level, square, and properly framed. Also check that the floor is level across the doorway to prevent alignment issues.
Step Two:
Measure & Cut the Jambs
Measure jamb leg length to ensure proper clearance above the floor. Leave a ½”–1″ gap above the top jamb so casing can cover the space cleanly.
Step Three:
Level the Door in the Jamb
Place the door in the opening and verify the head jamb is level before fastening anything permanently.
Step Four:
Secure the Hinge Jamb
Shim and nail the hinge jamb near the top hinge, then continue down. Adjust shims to maintain an even reveal and keep the jamb straight.
Step Five:
Secure the Strike Jamb
Shim and fasten the strike jamb from bottom to top, keeping a consistent gap between the door and the jamb.
Step Six:
Check Alignment
Close the door and make sure it contacts the door stop evenly. Make small adjustments until the fit is consistent.
Step Seven:
Cut Shims
Once everything is secure, trim excess shims flush with the wall using a utility knife or multi-tool.
Your Pre-Hung Door is Installed!
With the jambs secured and alignment checked, your pre-hung door is officially installed and ready for hardware and finishing touches. Taking the time to level, shim, and adjust properly will ensure smooth operation and a clean, professional look that lasts.