Possible Duplicate:
Doors are sticky and noisy when opened?
We have several old doors in our house, with possibly a great deal of paint build up on them. As a result they are very difficult to close solidly (and then open) - they stick a great deal. Is it better to "work" on the door or on the frame, and how do I find out where exactly they're sticking, and then what is the best way to resolve it?
You can also take a piece of paper and close the door on it, if it pulls out it is ok in not it is too tight, if you have tight fitting insulation don't put the paper all the way through. Sometimes just a gentle sanding with a block and medium sandpaper will loosen it up without having to repaint.
I would try rubbing some chalk on the doorframe, and then closing the door. Once you open the door again, the chalk will have rubbed off onto the door where it is sticking, and then you can use a block plane and shave some wood off of those areas.
To find out where it's sticking
Turn of all the lights in the room. Turn on all the lights in the adjoining room. Close the door. Examine the gap between the door and the frame, and any sticking points should be very, very evident.
My preferred method of resolving
Use a straight edge to mark the door where it's sticking, drawing a straight line down (or over) to where the gap is a reasonable size. In other words, you're drawing the line that would make the gap look even across the door, if it were cut at that point.
Then, use a plane to slowly edge off excess until you're close to the line. Sand down the rest for a smooth looking edge. If you've got a guide for a circular saw, you could also clamp it down along your line (or just above), and saw off the excess. Again, sand down to the final layer.
