You might feel it when using the door -- it sticks or rubs. Looking more closely, you notice a scrape on the jamb where the door contacts it. The problem might have occurred because the house has settled, or the jamb has loosened. It might be that the door has warped, or was installed improperly. It's not difficult to repair. A quick shave should do the trick.
Solutions and Options
Typically easy to find, the rub is usually on the doorknob side, at the top or bottom of the door. Focus on shaving only the part that rubs, tapering it for consistency.
Professionals use a hand-held power planer to shave doors. Power planers have a rotating head inside a lightweight body. It's quick and efficient, but requires some skill to operate.
Mark The Door
Close the door just enough so that it sticks or rubs -- don't shut it all the way. Examine the gap between the door and jamb on the interior side of the door -- the side that swings toward you. Locate the spot where the gap tapers, and the door rubs the jamb at the top or bottom. Draw a pencil line on the exposed edge of the door where it rubs.
Remove the screws holding the hinges to the jamb with a drill driver or screwdriver. Remove the hinges from the door. Clamp the door to two sawhorses, in a vertical position, with the side that rubs facing up.
Extend the pencil line so that it's at least 24 inches in length. The length of the shaved area is important to prevent shaving a dip or depression into the edge of the door. Use the pencil to scribble random lines, perpendicular across the vertical line. The scribbled lines are important, because they indicate how much material you'll be removing.
Set the depth gauge on the power planer to 1/64 inch. Place the planer on the edge of the door, with the opening for the cutter knife positioned at the far end of the scribbled section.
Tilt the back of the planer at a 15-degree angle, so that the flat, cutter edge of the planer is not touching the door. Pull the trigger to turn it on. Lower the tilt of the planer, easing the knife into the wood, until the base is flat on the door. Immediately begin pushing the planer forward in a steady motion, keeping pressure on it with both hands. Continue pushing until the planer glides off the end of the door.
Check the edge of the door to see if the scribbled lines have been removed. If not repeat the shaving process as many times as needed until they're gone. Two passes should equal about 1/16 inch. Four passes should be sufficient to shave it enough.
Rehang the door and check to see if it rubs. If it does, repeat the Steps. Finish by sanding the door with 100-grit sandpaper, followed by stain if needed, and two coats of lacquer.
The common belt sander is easier to control than a power planer, but caution is needed to avoid sanding dips or making the edge of the door uneven. The secret to shaving a door with a belt sander is to keep it moving. If you're not comfortable using a power planer, a belt sander can do the job, but it's more difficult to get it right.
Block planes are small, handheld planers. With a sharp knife extending from a metal base, you can use them to shave a door by hand. It's difficult to remove material fast, and requires patience, but it's relatively safe and effective.