From DIYinfo.org
Sticking Along One Side
Sticking is usually caused by a build-up of paint on the edge of the door and the frame. The problem is often worse in wet weather when the wood swells. If the trouble is not severe, simply rub the edge of the door with a candle or with dry powder lubricant.
If that is not enough, you will have to strip the door edge and frame.
1 Wait for a warm dry spell, and strip off the paint
2 It is a good idea to dry out the surface with a hot air gun before repainting.
3 Rub the stripped surfaces with glass paper and check that the door opens and closes easily
4 There should be a slight gap between the edge of the door and the frame, so run a thin knife blade all round the edge of the door when it is closed. Where the gap is insufficient, plane the edge of the door. It may be necessary to take the door off its hinges, and perhaps remove locks and bolts.
5 Sand, prime and paint the edge of the door. Let the paint dry before closing the door.
Sticking At The Bottom
If an external door sticks along its bottom edge, the problem is often caused by moisture being absorbed by the unpainted edge.
1 Wait for dry weather, then take the door off its hinges and thoroughly dry the bare edges with a hot air gun.
2 If the binding is severe, hold the door on one of its long edges in a portable workbench. Mark a line to work to, then plane downwards from the edge of the door to the center; this will avoid splintering the edge.
3 Prime and paint to match the rest of the door.
Sticking At The Top
You may be able to plane the top edge of a door without taking it off its hinges. It will have to be propped open firmly while you work from a stepladder.
Doors stick at the top much less frequently than at the bottom or side.
A Squeaking Door
Oil the hinge pins with an aerosol lubricant. Work the door backwards and forwards a few times to get the lubricant into the hinge, then wipe away surplus oil with a clean rag.
With rising butt hinges, lift the open door off the hinge pins and lightly smear them with grease or petroleum jelly. Wipe away the surplus after re-hanging the door.



