Doors that stick or rub are usually a maintenance issue, but can occasionally be a “Red Flag” under some circumstances.
The most common maintenance issues:
Too much paint
Some doors and jambs have been painted a number of times over the years. One coat builds up over another coat again and again. Eventually the doors rub or stick from having so many coats. Sanding down these doors and repainting will often correct the sticking problem.
Swelling or contraction
Humid summer weather may bring with it the problem of sticking doors. The wood absorbs moisture in the air and swells as a result. Homes that have poor ventilation where the air gets filled with moisture from cooking or hot showers in the bathroom can also have sticking or rubbing issues. In the winter, when things get cold, they contract. If a door was installed in the summer during a hot spell, then in the winter it may stick a little due to contraction.
Soil settled or shifted
When a house settles a little or there is some soil movement, then the doors may rub or stick. Usually adjustments or sanding the edges will improve how the door works.
The installer goofed
If the installer of the door failed to get sufficient clearances between the door edge and the jamb when installing the door, the jamb or just didn’t get it secured properly, then the door may rub.
Sand, plane and adjust
Sanding or planing the edge down a little, or making a little adjustment to the jamb will usually correct a door that rubs or sticks.
Hinges – check them
Check the hinges to see if one has come a little loose. Sometimes the problem is only that the screws need to be tightened.Who to consult? Qualified handymen, door hangers and finish carpenters.
DIY home owners may install or repair their doors on their own. Door hangers, finish carpenters and qualified handymen are the most proficient at installing and working on doors.