There are many reasons a door can stick. Here are a few simple suggestions to help you to get a door unstuck.
Step 1
Wash the door down with soap and water. Sometimes the door is just a little sticky and needs some cleaning. If soap doesn't work, try some "Goo Gone" or a similar stickiness removal product to remove the stickiness.
Step 2
Oil the hinges. Sometimes the hinges might be a bit sticky. If this is the case, put some oil in them to loosen them up.
Step 3
Find out where the door is sticking against the frame. Slide a piece of paper between the door and the frame when the door is closed. It should move easily all round the door. If it sticks anywhere, mark each side of this area on the door with a pencil. When you have determined where the door is sticking, remove the door and plane off approx 2mm / .078" at the marked areas. Before you plane any of the door, however, make sure you check out some of the other steps below. Planing a door is usually a last resort.
Step 4
Check for humidity. The problem may also be humidity, which can cause wood to swell, warp, and shrink.
Step 5
Replace the screws. Sometimes a good fix is to remove one screw from each hinge at the jamb and replace the screws with longer screws that will reach the house framing. Depending on the gap between the door jamb and the rough frame, you should be able to accomplish this with either an 1 3/4" (4.5 cm) or 2" ( 5 cm) wooden screw. Bring one of the old screws with you to the hardware store so you can buy the right size and material to match the old... Although it is a much easier fix to remove all screws in one lief at a time and drill 2 each 3/16" holes behind the lief and put 2 ea. 2.5" drywall screws thur the jamb mortize tightening each one a little more than the other alternating the tightening so you are using each screw as a lever to move the jamb closer to the stud.replace hinge screws. Much faster and more effective than finding a matching hinge screw that you will almost never find.
Step 6
Adjust the hinges. If the hinges are screwed in tightly and the door is still hanging askew in the frame, figure out which direction the doors needs to move in order for it to hang correctly. Usually, either the top hinge needs to move away from the door, or the bottom needs to move toward the door. In order to adjust the hinges, take the pin out of the hinge that needs adjustment, and bend the individual hinge knuckles of one side (aka "leaf") of the hinge in the direction it needs to go. This can usually be done easily with an adjustable wrench. Replace the pin, and repeat the process if it needs further adjustment.
Step 7
Adjust the door. If none of the above apply and you just can't find out why the door is sticking, it could be because the house has shifted. If this is the case, you might need to adjust the door to the proper height where it no longer sticks, or shave a bit off the bottom or top.
