A stuck door can cause a lot of problems in a house, especially if it is a main entry and exit point. There are a few things that can cause a door not to close properly. We've listed them below, along with ways to deal with them:
Sometimes there may be something preventing the door from closing which is not immediately obvious to the naked eye. This could be anything from a loose screw somewhere, on the lock or the strike plate perhaps to an accumulation of debris around the hinges or a badly installed weather strip. Check around the door on all sides for anything that may be stopping it from closing correctly.
Wooden doors and frames that are exposed to extreme weather conditions or internal humidity (like you might find in a poorly ventilated bathroom) are prone to absorbing moisture and expanding, causing the door to stick and not close correctly.
This can sometimes be dealt with by driving a large (~5cm) nail into the frame where the door is rubbing, pulling the frame tighter to the wall. It may not make much of a difference, but sometimes it can give you enough clearance to fix the issue.
If this doesn't resolve the problem, planing or sanding the edge of the door may be in order. You may need to remove the door to do this. If you’re planing or sanding the door, try not to take off too much wood at a time, though. You only want to remove enough to allow the door to close easily when expanded. If you take off too much and the door contracts again, you may be left with a sizeable gap.
If the door is leaning to one side or sitting lopsided on its hinges, it may be either that the hinge screws have come loose from the frame a little or that the hinges have been bent. This is very common for houses with kids who enjoy hanging off door handles! Often the hinges are loose enough or bent enough to allow for the door to sag and rub against the jamb.
If the hinges are OK and the screws are loose, simply tighten up the screws in the hinges to pull the door back up into shape. If the wood is too deteriorated for the screws to take a tight hold, you can remove the door and insert a piece of dowelling or, in a pinch, fill the hole with toothpicks and cut them flush with the wall to give the screws some purchase.
If your hinges are bent they will need to be replaced - provided that the door or frame aren't damaged and that you're handy enough with a screwdriver, this isn't too big a job. If possible, take the old hinges to the hardware store and make sure you get an exact replacement.
Removing and hanging doors is normally a two person job, so you may want to arrange for some help if you are planning on doing this.