Before you consider this option make sure the door cannot be adjusted. See the article 'Adjusting Doors' for more information.

Correct Door Opening Sizes

Door frames are usually installed in nominal sizes in increments of 2". For residential doors this would be from about 1' 6” to 3' 0”. The opening of the door frame will usually be exactly that size, 36” for a 3' 0” Door.

The door slab will be slightly undersized to allow the door to go in and out of the opening. A 3' 0” door slab will be 35 3/4” or slightly less. This would always be true, unless the door frame was improperly installed.

Door Frame Options

Check the size of the opening. Is it less than an even size? Is the door too big for the opening? Not good news and some work to fix.

Two choices at this point. Cut the door down to fit the opening or move the door jamb to the proper size. We may only be talking about an eighth or a quarter of an inch. Unfortunately, it is an important fraction of an inch.

Sanding and Planing a Door

If the door is just slightly off, you may be able to sand or plane. Keep in mind that both of these options will ruin the finish on the door. Part of the repair will be fixing the finish.

See the article 'Sanding and Planing a Door' for information on removing small amounts from a door.

Moving the Door Frame

If you choose to move the frame, get ready for some work.

Use a flat pry bar and carefully remove the trim on both sides of the strike side of the door frame. You will find that there is a gap between the door jamb and the framing for the wall. There are shims that keep the two spaced. Quickest easiest thing to do is use a reciprocating saw with a combination metal/wood cutting blade to cut out the shims.

With the shims gone, take a block of wood and a hammer and drive the door jamb toward the wall framing the needed distance. Make sure you take down anything that can be damaged or fall from the wall before you start pounding. Nothing worse than pounding on a wall and you hear your antique clock crashing to the floor on the opposite side.

Use the door to check your margins. With the door installed on the hinges, close it and adjust the jamb so that you have an even margin, an eighth of an inch or slightly more, along the strike side of the jamb. Use shims to hold the door the proper distance from the framing.

Re-Installing the Frame

I like square drive trim screws for door jambs, especially repair projects. Very positive attachment and eliminates a lot of pounding. Use 2 1/4” square drive trim screws to fasten the jamb. Go easy with a battery drill and draw them up until they set.

Sometimes they will pull the jamb in too far. Back them out, move the shim in a little and try again. Check the door and make sure it closes properly before you install the trim.

Clean up the trim and install it with finish nails or trim screws. Touch up the paint or stain as needed. Big job, were you successful? Find someone to pat you on the back, you have made a rather difficult door frame repair.