Why do doors stick in the summer?

Doors usually stick in the summer because wood soaks up moisture from humid air and swells. The door or its frame gets slightly bigger, and the small gap that let it swing freely closes up.

Wood takes in and gives off moisture all year long. Summer air holds more moisture, so wood doors and frames grow a little. In drier winter air, they shrink back. Bathrooms, laundry rooms and exterior doors that get rain are often the worst. Doors with unpainted top or bottom edges tend to absorb even more.

Humidity is not always the only cause. Loose hinge screws can let a door sag, so its top corner rubs the frame. A house that settles can also pull a frame out of square. If a door sticks all year, not just in summer, check the hinges first.

Start with the simple fixes. Tighten the hinge screws. A longer screw in the top hinge that reaches the wall framing can often pull the door back into place. Running the air conditioning or a dehumidifier lowers indoor humidity. Try not to plane or sand a door at the peak of summer, because it may leave a big gap in winter. If a door edge does get trimmed, seal the bare wood with paint or finish. If you have a door that still rubs, here is how our door adjustments work.