I want to install a new door in my bedroom (replacing a door) with an pre-hung door - standard width is 4 1/2in. The wall is paneled, not dry wall - so the width of the existing jamb is 4 inches. Can I take 1/2 inch off the pre-hung jamb? And how? Thank you!



  1. Remove the hinges and door slab.
  2. Mark the location of the jamb stops with masking tape on each side, and then remove them by carefully prying them away from the jambs. They're usually nailed or stapled in place.
  3. Disassemble the jamb by carefully tapping apart and removing the nails/staples/screws at the corners.
  4. Run your jamb through a table saw, splitting it underneath the stop location. Run them through again to remove additional material to achieve the jamb depth desired.
  5. Combine the two halves of each jamb component using wood glue and clamps. Allow to dry overnight.
  6. Reassemble the jamb corners using your fastener of choice, then install the stops, hinges, and slab.
  7. Hang the door as usual.


It may be simpler to just fur out the back of your door casing (trim) to accommodate the extra depth. If done well this is nearly invisible, plus you have the option to convert to drywall later without replacing the jamb.


It would have been prudent for the paneling installer to have furred out the wall framing to achieve the half-inch thickness for just the reason you've encountered. That's water under the bridge, obviously, but it's a thought for next time.

  • Since it's only 1/2 inch, why not simply trim it off the non-hinge edge of the jamb components? The door would not be centered in the jamb (by 1/4 inch), but so what?
    – bib
    Jan 11 '17 at 19:20
  • I assume a paint-grade or hardwood veneer. (Doors aren't normally centered anyway.)
    – isherwood
    Jan 11 '17 at 19:27
  • After all that, I wonder if it still makes sense to go with a pre-hung door...
    – mmathis
    Jan 11 '17 at 19:38
  • That's massively less complicated than building your own jamb. I could do it in about 20 minutes.
    – isherwood
    Jan 11 '17 at 19:43
  • If the OP has the tools this method would give a professional look. I like to reuse material when I can.+
    – Ed Beal
    Jan 11 '17 at 19:50

If you are replacing the whole door and frame spend a few dollars more and buy a split jamb complete door. they sell them at Home Depot and Lowes. They can show you " how to" install if you need help.

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