How to Replace a Pre-Hung Garage Entry Door

When just the door component of a prehung door unit needs to be replaced, often a simple slab door can be used. A pre-hung door unit consists of a door and jamb with components such as the hinges, locks and knobs already in place, making the initial installation of the unit much easier. A slab door is essentially a blank door, lacking hinge emplacements or knob and lock holes. By using the pre-hung door as a template, installing a slab door is a way to save money if you're handy enough to tackle this project. Taking the time to plan your project before starting ensures a smooth door transition.

Assistant
External replacement door
Ruler
Screwdrivers
Wood chisel
Drill
2-1/8-inch hole saw bit
7/8-inch spade bit

Instructions

- 1
  Remove the old door from the pre-hung unit by unscrewing the hinges while a second person holds the door. Start with the bottom hinges and work your way to the top.
- 2
  Remove the knob and lock setup from the old door.
- 3
  Lay the old door over the new door and mark off the locations for the hinges, lock and knobs. Remember, if the new door is too tall, cut from the bottom of the door, not the top. Also, be sure to mark the hinge location as well as the depth of the recession they are installed in, which is called a mortise.
- 4
  Score the edges of the mortise location with a wood chisel and gently cut away the wood in the mortise using the chisel. Periodically check the mortise by placing the hinge in it to verify the depth and proper fit.
- 5
  Drill the hole for the doorknob in the location marked previously from the old door, using a hole saw bit.
- 6
  Drill the hole for the latch hole using a spade bit.
- 7
  Install the doorknob and lock set into the door, following the manufacturer's instructions.
- 8
  Screw the hinges into the door in the mortises and then screw the other end of the hinges back into the door jamb while an assistant holds the door up.

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Doors