How to Adjust a Door Threshold

An exterior door threshold is designed to seal off airflow under the door.

Prevent air leaks under your doors by adjusting thresholds.Prevent air leaks under your doors by adjusting thresholds.
This prevents loss of cooling or heat in homes and buildings while they're closed for indoor climate control. The threshold is adjustable to seal up the crack between itself and the door if a draft is detected from under an entry door. Keep a door threshold adjusted properly to prevent heat and air conditioning from escaping your home or office.

Check for the location of cracks between an exterior door threshold and an exterior door on a sunny day. Get on your hands and knees in front of the door on the inside and look between the threshold and door to see where the sunlight comes through. A little light at the corners is acceptable.

Open the door and adjust the threshold by turning the screw closest to the spot where light came through. Turn the screw counterclockwise with a Phillips screwdriver to raise the door threshold.

Lay the edge of a framing square over the door threshold to see if it's straight and level. Adjust any other screws to the necessary height to make the top of the threshold level. Turn screws clockwise to lower a section of the threshold if necessary.

Close the exterior door and check for light shining through from underneath after making the adjustment. Make further adjustments if necessary to close the crack under the entry door.

Things You Will Need

  • Phillips screwdriver
  • Framing square

About the Author

Jonra Springs began writing in 1989. He writes fiction for children and adults and draws on experiences in education, insurance, construction, aviation mechanics and entertainment to create content for various websites. Springs studied liberal arts and computer science at the College of Charleston and Trident Technical College.