How to Install a Door Correctly

Installing a door correctly is one of the most satisfying DIY projects you can tackle. A properly hung door swings freely, latches smoothly, and seals tightly. Here's a complete step-by-step guide.

Types of Door Installation

• Pre-hung door: Door comes already mounted in a frame; easiest to install, best for new openings
• Slab door: Door only, no frame; fits into an existing frame; requires more skill

This guide covers slab door installation into an existing frame — the most common DIY scenario.

What You'll Need

• New door slab
• Hinges (3 for doors over 80")
• Door knob and latch set
• Strike plate
• Chisel and mallet
• Drill and bits
• Carpenter's square and level
• Pencil and measuring tape
• Hand plane or circular saw (for fitting)

• Amazon Basics Self-Closing Door Hinge 3.5" — satin nickel, hardware included
• CML Keyed Entry Door Knob Set — solid stainless steel, includes latch and all hardware
• Amazon Basics 8-Piece Wood Chisel Set — for cutting hinge mortises
• Mr. Pen Carpenter's Square 8×12" — verify frame squareness before starting
• AikTryee Laser Level Kit — check frame plumb

Step 1: Check the Frame

Before buying a door, check the frame is square and plumb. Use a carpenter's square on the corners and a level on the sides. An out-of-square frame means the door will never fit properly.

Step 2: Measure and Fit the Door

Measure the opening height and width. The door should be 1/8" narrower than the opening on each side and 1/8" shorter than the opening at the top. This gives proper clearance. Mark and trim the door if needed with a circular saw or hand plane.

Step 3: Mark and Cut Hinge Mortises

Standard hinge placement: top hinge 7" from top, bottom hinge 11" from bottom, middle hinge centered between them. Hold the door in the opening, mark hinge positions, then chisel the mortises to the depth of the hinge leaf.

Step 4: Attach Hinges to the Door

Screw the hinge leaves to the door first. Use 3" screws for at least one screw per leaf to reach the stud.

Step 5: Hang the Door

With a helper, lift the door into the opening and align the hinge leaves with the frame mortises. Insert the hinge pins from the top down. Test the swing.

Step 6: Install the Latch and Knob

Mark and drill the knob hole (2-1/8" diameter) and latch hole (1" diameter) at the correct backset (2-3/8" or 2-3/4" from door edge). Install the latch, then the knob set.

Step 7: Install the Strike Plate

Close the door and mark where the latch bolt hits the frame. Chisel the mortise and screw the strike plate in place.

• Gator Door Strike Plate — universal fit, satin nickel

Step 8: Test and Adjust

Open and close the door. It should swing freely with even gaps on all sides (1/8" top and sides, 3/8"–1/2" bottom). Adjust hinges with shims if needed.